Tending the Wilted Flower: The Role of Psychological Need

Fulfillment in Treatment for Depression

by

Matthew Quitasol

A thesis submitted in conformity with the requirements

for the degree of Masters of Arts

Graduate Department of Psychological Clinical Sciences

University of Toronto

© Copyright by Matthew Quitasol 2016

ii

Tending the Wilted Flower: The Role of Psychological Need Fulfillment

in Treatment for Depression

Matthew Quitasol

Masters of Arts

Graduate Department of Psychological Clinical Science

University of Toronto

2016

Abstract

The present research integrated the principles of self-determination theory (e.g. Deci & Ryan,

2000) with the cognitive mediation model of depression (e.g. Whisman, 1993). Participants with

a SCID-IV diagnosis for major depressive disorder were randomly assigned to 16 weeks of

cognitive therapy or anti-depressant medication. They also completed indices of depression

severity, neuroticism, and psychological need fulfillment, at four assessment points (pre-

treatment, week 4, week 8, and week 16). Psychological need fulfillment increased over the

course of treatment and was negatively correlated with depression severity. Increases in

psychological need fulfillment predicted decreases in depression severity over and above the

effects of time, neuroticism, and negative cognitions. The temporal association between changes

in psychological need fulfilment was bidirectional, and significantly more pronounced in the

cognitive therapy condition. The association between changes in psychological need fulfillment

and changes in depression severity was not mediated by reduced negative cognitions.

iii

Acknowledgments

First and foremost, I am grateful to my supervisor, Marc A. Fournier. His mentorship, guidance,

patience, and insight have been paramount to my development as a young scientist, as well as my

navigation of the expected and unexpected trials of academia and clinical graduate work. I am

also grateful to my committee members, R. Michael Bagby and Lena C. Quilty, whose support

and clinical expertise enabled me grow as a clinical researcher and push this project beyond my

expectations. I would like to thank my labmates, Stefano I. Di Domenico, Nic Weststrate, and

Vicki (Mengxi) Dong for vetting my ideas, providing their invaluable feedback, and their

friendship. I would also like to thank Nina Dhir, Minnie Kim, Hanan Domloge, and Liz

Pulickeel. Your assistance and advice regarding the administrative and logistic affairs of

graduate school have helped to lighten the heavy burdens associated with a clinical program. I

am also grateful to the members of my cohort, Dean Carcone, Kyrsten Grimes, Le-Anh Dinh-

Williams, and Phil Desormeau. Your friendship and support have been instrumental in surviving

our forging into clinicians. I would also like to thank my brothers, Chris Quitasol and Mike

Quitasol. Your constant love and unbreakable support keep me “humble.” Finally, I am eternally

grateful and indebted to my parents whose unwavering support and many sacrifices have enabled

me to pursue my passion.

iv

Table of Contents

Acknowledgments.......................................................................................................................... iii

Table of Contents ........................................................................................................................... iv

List of Tables ...................................................................................................................................v

List of Figures ................................................................................ Error! Bookmark not defined.

Chapter 1 Introduction..................................................................................................................1

Chapter 2 Method ..........................................................................................................................9

Chapter 3 Results .........................................................................................................................13

Chapter 4 Discussion .....................................................................................................................25

References .....................................................................................................................................31

Appendix ........................................................................................................................................38

v

List of Tables

Table 1. Descriptive statistics and reliabilities.

Table 2. Zero-order correlations between psychological need fulfillment and depression

collapsing across participants and assessment points.

Table 3. Models of change in psychological need fulfillment and depression over t ime.

Table 4. Models of Change in Depression as a Function of Changes in Psychological Need

Fulfillment.

Table 5. Models of Change in Depression as a Function of Changes in Psychological Need

Fulfillment and Other Personality Variables.

Table 6. Models of Change in Depression as a Function of Changes in Psychological Need

Fulfillment and Negative Cognitions.

Table 7. Lagged Models of Change in Psychological Need Fulfillment and Depression Over

Time.

Table 8. Impact of Other Personality Variables on Lagged Models of Change in Psychological

Need Fulfillment and Depression Over Time.

Table 9. Stepwise Models for Assessing the Mediating Role of Change in Negative Cognitions

in the Relationship Between Psychological Need Fulfillment and Depressive Symptoms.

Table 10. The Impact of Treatment Group and Sex on the Association between Psychological

Need Fulfillment and Depressive Symptoms.

1

Chapter 1 Introduction

Carl Rogers (1959) conceptualized psychotherapy as a set of facilitative conditions that

nurture the client’s inherent tendencies to develop and enhance their capacity for autonomous

functioning. Just as wilted flowers can be tended back to health by providing them with sunlight,

nutrient-rich soil, and water, Rogers (1959) maintained that providing clients with nurturing

conditions, such as unconditional positive regard, was integral to clients’ psychological growth.

In the present research, we utilized self-determination theory (SDT), a contemporary framework

which maintains that all living organisms require the fulfillment of innate psychological needs, to

examine similar nurturing conditions that are theorized to be integral to psychological growth.

Specifically, we examined the extent to which clients’ basic psychological needs for autonomy,

competence, and relatedness are fulfilled over the course of cognitive therapy and

pharmacotherapy for depression, and how the fulfillment of these needs scaffolds healthy

psychological growth and cognitive change.

Self-Determination Theory

SDT is a macrotheoretical framework of personality, motivation, and optimal

psychological development (Ryan, 1995; Deci & Ryan, 2000; Deci & Ryan, 2008). Central to

SDT are three basic psychological needs. Autonomy describes the experience of one’s behavior

as volitional and reflective of one’s own values and interests; behavior is experienced as being

self-initiated and self-endorsed (Ryan, 1995; Deci & Ryan, 2000; Deci & Ryan, 2008).

Competence describes the experience of effectance, mastery, and growth in one’s activities vis-à-

vis the environment (White, 1959; Ryan, 1995; Deci & Ryan, 2000; Deci & Ryan, 2008).

Relatedness describes the experience of feeling cared for and connected to close others; a sense

of belongingness and the feeling that one matters (Deci & Ryan, 2000; Deci & Ryan, 2008;

Ryan, 1995).

SDT maintains that healthy psychological functioning is facilitated by conditions that

support psychological need fulfillment. Just as all plants flourish when they are provided with

nutrient-rich soil, water, and sunlight, all people thrive and maximize their psychological

integrity when they experience autonomy, competence, and relatedness (Deci & Ryan, 2000).

Conversely, just as all plants languish and wither when deprived of water, or when planted in

contaminated soil, so too do all people languish and wither when their psychological needs are

deprived or frustrated. Indeed, a substantial body of evidence has demonstrated that fulfillment

of autonomy, competence, and relatedness fosters psychological growth, integrity, and well-

being; similarly, deprivation or frustration of these psychological needs degrades psychological

integrity, resulting in psychopathology and ill-being (Bartholomew, Ntoumanis, Ryan, Bosch, &

Thøgersen-Ntoumani, 2011; Deci & Ryan, 2000; Deci & Ryan, 2008; Ferrand, Martineent, &

Durmaz, 2014; Reis, Sheldon, Gable, Roscoe, & Ryan, 2000; Ryan, 1995; Ryan, Deci, Grolnick,

& La Guardia, 2006; Vansteenkiste, Lens, Soenens, & Luyckx, 2006; Vansteenkiste & Ryan,

2013).

Although SDT has approached the definition of autonomy from the perspective of self-

governance and the self-authorship of behavior, the operational definition of autonomy has

historically been heterogeneous across the literature. Notably, Beck (Beck, Epstein, Harrison, &

Emery, 1983) conceptualized autonomy as a personality construct reflecting individual

differences in vulnerability to depression. For Beck and colleagues, the highly autonomous

individual places strong emphasis on personal freedom, mobility, individuality, achievement, and

is exceptionally sensitive to events perceived as threatening to these values. Beck maintained that

these qualities make the autonomous individual highly susceptible to reactive depression. As

such, Beck’s use of the term autonomy is more consistent with that of an individual difference

characteristic, whereas SDT uses the term autonomy to refer to a basic psychological need that

characterizes an experiential requirement of all individuals. Previous research has demonstrated

this heterogeneity in the operational definition of autonomy (Hmel & Pincus, 2002). In their

psychometric review of various measures of autonomy, Hmel and Pincus conducted a principle

axis factor analysis and found that autonomy as conceptualized by SDT, and autonomy as

conceptualized by Beck, were subsumed by separate and distinct factor structures. These factor

structures were not only separate, but also theoretically consistent. Indices associated with SDT’s

conceptualization of autonomy as volitional, and reflective of one’s own values and interests

loaded onto a factor conceptualized as self-governance. This underlying factor was characterized

by psychological adaptation, self-directness, positive emotionality, and intrinsic motivation,

qualities that are congruent with the literal meaning of autonomy (i.e., “self-ruling”). Indices

associated with Beck’s conceptualization of autonomy loaded onto a factor conceptualized as a

depressogenic vulnerability. In contrast to self-governance, this underlying factor was

characterized by a lack of agentic quality, an inclination towards negative affect, and

interpersonal detachment tapping a construct reminiscent of a cognitive personality style that

confers vulnerability to depression (Hmel & Pincus, 2002).

Self-Determination Theory and Treatment for Depression

The role of autonomy is considered by SDT to be an integral component of motivation

during treatment in psychotherapy (Ryan & Deci, 2008; Ryan, Lynch, Vansteenkiste, & Deci,

2011). The majority of clinical research applying SDT in the treatment for depression has

emphasized understanding how clients internalize and freely endorse treatment-related behaviors

in order to facilitate healthy psychological change. According to SDT, a depressed client’s

willingness to internalize and participate in treatment-related behaviors for healthy psychological

change can vary in the degree to which it is autonomously motivated (Deci & Ryan, 2000). Four

different qualities of internalization lie along this continuum of autonomous motivation: external

regulation, introjected regulation, identified regulation, and integrated regulation.

External regulation of treatment-related behaviors is the least autonomously motivated

form of internalization during therapy. Clients who are externally regulated participate in their

treatment in order to satisfy an external demand or reward contingency (Deci & Ryan, 2000).

When demands and reward contingencies regarding participation in therapy emanate from within

the client, internalization is said to be introjected. Introjected clients participate in treatment to

avoid feelings of guilt or anxiety (Deci & Ryan, 2000). A more autonomously motivated form of

internalization during therapy is identified regulation. Identified clients participate in their

treatment because it is personally important to them and instrumental to maintaining their mental

health. Finally, the most autonomously motivated form of internalization is integrated regulation.

Integrated clients fully assimilate and wholeheartedly endorse their participation in treatment

because healthy psychological functioning is congruent with their core values and underlying

sense of self. Indeed, previous research has found that depressed clients report fewer symptoms

and show a higher probability of remission when they are autonomously motivated to participate

in their treatment (Michalak, Klappheck, & Kosfelder, 2004; Pelletier, Tuson, & Haddad, 1997;

Ryan & Deci, 2008; Zuroff, Koestner, Moskowitz, McBride, Marshall, & Bagby, 2007).

According to SDT, a depressed client’s internalization of treatment-related behaviors

during therapy is actively supported by the clinician through establishing an autonomy-

supportive treatment context (Ryan & Deci, 2008; Sheldon, Joiner, Pettit, & Williams, 2003;

Ryan, Lynch, Vansteenkiste, & Deci, 2011). Autonomy support is comprised of three distinct

components (Deci & Ryan, 1985). The first component requires that the clinician acknowledge

the perspective of the client through validating and honoring his or her unique world view. The

second component requires that the clinician provide the client with reasonable and meaningful

choices, such that he or she can freely determine the course of his or her treatment. Finally, when

choice cannot be provided to the client, it is important for the clinician to provide the client with

a meaningful rationale for why he or she does not have a choice. When depressed clients are

provided with the necessary conditions for cultivating autonomous motivation over the course of

a variety of treatments for depression, they are better able to engage in treatment-relevant

behaviors and cultivate healthy psychological change (McBride, Zuroff, Ravitz, Koestner,

Moskowitz, Quilty, & Bagby, 2010; Ryan & Deci, 2008; Zuroff, Koestner, Moskowitz,

McBride, & Bagby, 2012).

Although autonomy is often discussed with more depth and elaboration among SDT

researchers because of its long debated controversy (Ryan, Deci, Grolnick, & La Guardia, 2006),

as well as its importance for describing qualities of motivation and behavior, SDT researchers

maintain that fulfillment of all three psychological needs is necessary for optimal motivation and

internalization (Deci & Ryan, 2000; Deci & Ryan, 2008; Ryan, 1995). Indeed, it is simply not

enough for a behavior or task to be congruent with one’s values, interests, and goals; one must

also feel capable and competent in the task. Moreover, given that most behavior does not occur

in an interpersonal vacuum, it is often not enough for one to be competent and volitional in their

actions; how one acts is also meaningfully connected to other people, especially close others.

Thus, just as a plant cannot grow by forgoing water for sunlight or nutrient-rich soil without the

risk of compromising its integrity, SDT maintains that psychological needs contribute equally to

healthy psychological growth.

Another corollary of the plant metaphor used by SDT to communicate the importance of

psychological need fulfillment entails that wilted and languishing plants can be transplanted to

more nurturing conditions in order to cultivate their integrity and promote healthy growth. By

analogy, therapeutic interventions should provide similar conditions for individuals with major

depressive disorder to enhance their psychological need fulfillment in order to promote healthy

and adaptive psychological change (Ryan & Deci, 2008). However, the majority of research

concerned with psychological need fulfillment in depressed populations over the course of

treatment has focused largely on the growth manifestations that emerge as a result of

autonomous functioning and autonomy-supportive conditions. Specifically, clinical research in

SDT has primarily focused on clients’ internalization and motivations to seek out and maintain

their treatment, and how these motivations affect treatment outcomes (Lynch, Vansteenkiste, &

Deci, 2011; Ryan & Deci, 2008; Ryan). Moreover, given that autonomy-supportive conditions

have been found to facilitate the fulfillment of all three psychological needs (Deci & Ryan, 2000;

Ryan & Deci, 2008), a key limitation of the existing research bridging SDT with treatment for

depression has been the largely untested assumption that clients experience increases in

psychological need fulfillment over the course of treatment. This largely untested assumption—

that psychological needs have either been fulfilled or frustrated (i.e. a converse error)—is also

present in research bridging SDT with other clinical populations, including obsessive compulsive

disorder (e.g., Assor & Tal, 2012) and eating disorders (e.g., Vansteenkiste, Soenens, &

Vandereyecken, 2005). Although some emerging clinical research using SDT as a framework

has begun to test this assumption (e.g., Verstuyf, Vansteenkiste, & Soenens, 2012; Verstuyf,

Vansteenkiste, Sonenes, Boone, Mouratidis, 2013), the majority of SDT research involving

clinical populations has focused less on exploring changes in psychological need fulfillment or

frustration, and focused more on the outcomes of processes which imply psychological need

fulfillment or frustration.

Self-Determination Theory and the Cognitive Mediation Model

According to the cognitive mediation model of depression, the primary process of healthy

psychological change during cognitive therapy comes from change in negative cognitions (Beck,

Rush, Shaw, & Emery, 1979; Whisman, 1993). Depression is rooted in a latent depressogenic

self-schema (Beck, 1967; Beck, Rush, Shaw, & Emery, 1979; Segal & Ingram, 1994) that, upon

activation, causes negative perceptual and cognitive processing biases. These negative cognitions

can transform banal sad moods into seemingly inescapable singularities of profound negativity,

resulting in major depressive disorder. Cognitive therapy works specifically to alter the function,

content, and structure of the depressogenic self-schema.

However, the processes governing the relationships between therapeutic factors and

healthy psychological change can be very complicated (Morgenstern & Longabaugh, 2000). Oei

and Free (1995) found that changes in cognitive style were related to changes in depression

across 44 outcome and process studies of therapy for depression, but that cognitive change was

not exclusive to cognitive therapeutic interventions. Similarly, Garratt, Ingram, Rand, and

Sawalani (2007) found evidence for cognitive change in the treatment of depression not only in

cognitive therapy, but also in noncognitive therapy and psychopharmacology. Given that

cognitive change does not seem to be specific to cognitive therapy, it is important to identify

additional theoretical frameworks (and their corresponding processes) with which to expand our

understanding of change processes in treatment. This is especially important for delineating both

specific and non-specific factors in treatment and how they contribute to outcomes.

One recent study has demonstrated the promise of applying SDT principles to the study

of cognitive change in depression. Dwyer, Hornsey, Smith, Oei, and Dingle (2011) investigated

the role of autonomy over the course of cognitive behavioral group therapy for depression. They

found that levels of autonomy fulfillment increased following four weeks of treatment; levels of

autonomy fulfillment were inversely related to depression severity, an association that was

mediated by reduced negative cognitions. An important limitation of this research was its

exclusive focus on the need for autonomy to the neglect of the other two needs. Indeed, given

that cognitive therapy provides opportunities for individuals to hone personal as well as

interpersonal skills (e.g. Greenberger & Padesky, 1995), there is no reason to assume that

relatedness fulfillment and competence fulfillment are met any differently compared to

autonomy fulfillment over the course of treatment.

Overview of the Present Study

In an effort to further clarify the role of SDT in the treatment of depression and building

on the existing work of Dwyer and colleagues (2011), the present study will examine how

autonomy, competence, and relatedness fulfillment change over the course of cognitive therapy

and pharmacotherapy for depression. Moreover, we will examine the temporal relationship

between changes in psychological need fulfillment and changes in depression severity. Given

that SDT posits a bidirectional relationship between psychological need fulfillment and mental

health (Deci & Ryan, 2000), we will examine whether clients experience an increase in

psychological need fulfilment prior to decreases in depression severity, subsequent to decreases

in depression severity, or both. Finally, in keeping with the cognitive meditation model of

depression, we will examine whether changes in negative cognitions mediate the temporal

relationship between psychological need fulfillment and depression severity.

Psychological Needs and Personality Change. Insofar as our goal is to examine the

relationship between changes in psychological need fulfillment and changes in depression

severity, it is also important to demonstrate that changes in psychological need fulfillment are

not accounted for by other personality variables which have been found to change over the

course of treatment, such as neuroticism (e.g., Renner Penninx, Peeters, Cuijpers, Huibers, 2013)

and attachment style (Kinley & Reyno, 2013; Marmarosh & Tasca, 2013; Maxwell, Tasca,

Ritchie, Balfour, & Bissada, 2014; Travis, Bliwise, Binder, & Horne-Moyer, 2001). Thus, we

will also examine changes in neuroticism and attachment style as covariates in the relationship

between changes in psychological need fulfillment and changes in depression severity.

Psychological Needs and Antidepressant Medication. In addition to psychotherapy, SDT

has also demonstrated the effect of autonomous motivation on health outcomes which require

adherence to various medication regiments, including regiments for antidepressant medication

(ADM; Bruzzese, Idalski Carcone, Lam, Ellis, & Naar-King, 2014; Williams et al, 2009;

Williams, Rodin, Ryan, Grolnick, & Deci, 1998; Zuroff et al., 2007). However, given the

humanistic foundations of SDT (Deci & Ryan, 2000; Deci & Ryan, 2008; Ryan, 1995) and our

goal of examining how psychological need fulfillment changes over the course of treatment, a

more pertinent question regarding the relationship between SDT and ADM concerns whether or

not ADM is able to produce changes in psychological need fulfillment that differ from those

produced in psychotherapy. Psychological needs are qualities of experience that emerge from

interactions with the environment (e.g. social contexts; Vansteenkiste & Ryan, 2013). It is

possible that ADM can alleviate symptoms that prevent depressed individuals from actively

engaging with their environment and conditions that facilitate psychological need fulfillment.

Consequently, we will also exam the role ADM in changes in psychological need fulfillment.

Research Hypotheses

We propose the following hypotheses:

1. Because psychological need fulfillment promotes healthy functioning, we predict that

psychological need fulfillment—that is, fulfillment of autonomy, competence, and relatedness—

will be negatively correlated with depression severity.

2. We predict that psychological need fulfillment will increase over the course of both cognitive

therapy and pharmacotherapy.

3. We predict that this increase in psychological need fulfillment will be associated with a

decrease in depressive symptoms over the course of treatment.

4. Given that SDT posits a bidirectional relationship between psychological need fulfillment and

mental health, we will construct a series of lagged exploratory models to test both (a) the effect

of psychological need fulfillment on subsequent depression severity and (b) the effect of

depression severity on subsequent psychological need fulfillment.

5. We predict that any temporal associations obtained between change in psychological need

fulfillment and change in depression severity will not be fully accounted for by change in

attachment style or neuroticism; psychological need fulfillment will have incremental validity in

its association with depression severity over and above the effect of change in attachment style

and the effect of change in neuroticism.

6. Insofar as psychological need fulfillment contributes to existing processes of healthy

psychological change during treatment for depression, we predict that increases in psychological

need fulfillment will be associated with a decrease in negative cognitions, and that increases in

psychological need fulfillment will indirectly predict decreases in depressive symptoms through

reduced negative cognitions.

7. Although the prototypical therapeutic setting is characterized as a supportive environment

conducive to psychological need fulfillment, antidepressants may also facilitate depressed

participants’ interaction with need-supportive conditions thereby enhancing their capacity for

need-fulfillment. However, the frequency with which therapy clients meet with their therapists

might afford them access to more psychological need fulfillment. Therefore, we predict that

participants assigned the cognitive therapy will demonstrate larger increases in psychological

need fulfillment over the course of treatment, as well as a more robust temporal effect of

psychological need fulfillment on depression severity compared to participants assigned to

pharmacotherapy.

9

Chapter 2 Method

Participants

Sample participants for the present investigation were recruited through media

advertisements and physician referral by the CAMH Clinical Research Department for a larger

study examining the cognitive mediation model of depression, and who met DSM-IV criteria for

major depressive disorder (MDD) based on the Structured Interview for DSM-IV, Axis I

disorders, Patient version (SCID-I/P; First, Spitzer, Gibbon, & Williams, 1995). Of the 1,415

potential participants who responded via media advertisements and physician referrals, 455

individuals expressed interest in participating and consented to a brief phone interview.

Following the telephone screening phase, 213 individuals were interested in participation and

eligible for a clinical interview. Of those individuals who completed a clinic screen, 140 were

eligible for and interested in participation. Participants were excluded if they met any of the

following criteria: (1) SCID-I/P diagnosis of (a) bipolar disorders, (b) psychotic disorders, and

(c) substance use disorders; (2) organic brain syndrome; or (3) current ADM or ECT treatment in

the past 6 months at the time of data collection. A total of 104 patients met criteria for

participation and were assigned to treatment.

Measures

Participants completed six self-report measures.

Balanced Measure of Psychological Needs (BMPN). Psychological need fulfillment was

indexed using the 18-item BMPN (Sheldon & Hilpert, 2012), a self-rated measure of perceived

autonomy, competence, and relatedness fulfillment. Participants were asked to report on their

psychological need fulfillment during the past week. Each psychological need was indexed via a

6-item subscale consisting of three items that measured need satisfaction (e.g. “I was successful

completing difficult tasks and projects”) and three items that measured need dissatisfaction (e.g.

“I did something stupid that made me feel incompetent”). Participants were asked to indicate the

extent to which they agreed with each of the 18 items using a 7-point scale ranging from 1

(Strongly disagree) to 7 (Strongly agree). The descriptive statistics of self-rated psychological

need fulfillment are summarized in Table 1.

Beck Depression Inventory-II (BDI-II). Participants also completed the BDI-II (Beck,

Steer, & Brown, 1996) a 21-item self-rated measure of depression. Participants were presented

with 21 groups of statements; after reading each group of statements carefully, participants

selected the one statement in each group that best described the way that they had been feeling

during the past two weeks, including the day on which they were completing the measure.

Statements for each item (e.g. sadness) were ranked on a 4-point scale ranging from 0 (e.g. I do

not feel sad) to 3 (e.g. I am so sad or unhappy that I can’t stand it). The descriptive statistics of

self-rated depressive symptoms are summarized in Table 1.

Cognitive Errors Questionnaire (CEQ). Negative cognitions were indexed using the

CEQ, a self-rated measure of four types of cognitive errors: catastrophizing, overgeneralization,

personalization, and selective abstraction (Lefebvre, 1981). Catastrophizing refers to when the

outcome of an event or an event in and of itself as perceived as being catastrophic or

unsuccessful. Overgeneralization refers to when the outcome of one experience or event is

believed to apply to other experiences or events in the future. Personalization refers to when

personal responsibility is assumed for negative events or negative events are interpreted to have a

personal meaning. Selective abstraction refers to when attention is only paid to a single, negative

detail of an event, ignoring the context in which that event took place.

Participants were presented with 48 different situations that might occur in daily life (e.g.

being told by your boss that you are being laid off due to a slowdown in the industry). Each

situation was followed by a possible thought that a person in that situation might have (e.g. “I

must be doing a lousy job or else he wouldn't have laid me off"). Participants were asked to

imagine themselves in each of the 48 situations and rate how similar each possible thought was

to how they would think in that situation using a 5-point scale ranging from 0 (Not at All) to 4

(Extremely). The descriptive statistics of cognitive errors are summarized in Table 1.

Dysfunctional Attitudes Scale (DAS). Negative cognitions were also indexed using the

DAS (Weissman & Beck, 1978), which was originally developed to test the core premise of

Beck’s (1967) cognitive model of depression: maladaptive thinking styles and attitudes underlie

vulnerability to depression. Participants were presented with a list of 40 beliefs and attitudes and

asked to rate the extent to which they agreed that a certain attitude or belief described how they

thought using a 7-point scale ranging from 1 (Totally Agree) to 7 (Totally Disagree). The

descriptive statistics of self-rated dysfunctional attitudes are summarized in Table 1.

The Revised NEO Personality Inventory (NEO-PI-R). Participants’ personality traits were

assessed using the NEO-PI-R, a questionnaire developed through rational and factor analytical

methods, to measure the Five Factor Model of Personality: neuroticism, extraversion,

agreeableness, openness, and conscientiousness (Costa & McCrae, 1992). Participants were

presented with 240 statements (e.g., “I often feel helpless and want someone else to solve my

problems” and “I’m a superior person”) and indicated the extent to which they agreed with each

statement on a 5-point scale. The descriptive statistics of self-rated personality traits are

summarized in Table 1.

Experiences in Close Relationships-Revised Adult Attachment Questionnaire (ECR-R).

Participants also completed the ECR-R, a 36-item self-rated index of attachment style comprised

of two factors, anxiety and avoidance, at Week 0 and Week 16 (Fraley, Waller, & Brennan,

2000). Participants were asked to report on how they generally felt in their romantic

relationships. Participants indicated the extent to which they agreed or disagreed with each item

(e.g. “I’m afraid that I will lose my partner’s love”) using a 7-point scale ranging from 1

(Disagree Strongly) to 7 (Agree Strongly). The descriptive statistics of self-rated attachment style

are summarized in Table 1.

Procedure

Participants were randomly assigned to 16 weeks of cognitive behavioral therapy or

antidepressant medication (CANMAT, 2001). During data collection, participants completed the

self-rated Beck Depression Inventory-II (BDI-II; Beck, Steer, & Brown, 1996) each week.

Participants also completed a battery of measures at four assessment points (pre-treatment, week

4, week 8, and week 16) to assess severity of depression, personality traits, and negative

cognitions. Participants also completed a measure of attachment style during their first and last

assessment point. A measure of psychological need fulfillment was also included in this battery

later in the data collection. Of the 104 participants who initiated treatment, 92 completed at least

eight weeks of CBT or pharmacotherapy. Five participants dropped out of the CBT treatment

group and seven participants dropped out of the pharmacotherapy treatment group. Of the 92

participants who completed a minimum of eight weeks of treatment, 51 (30 males, 21 females)

completed measures of psychological need fulfillment. Snijders and Bosker (2012) have

indicated that Level 2 sample sizes of over 30 participants can be considered large enough for the

purposes of multilevel modeling, the primary analytic approach of the present study. Of these 51

participants, 29 had been assigned to CBT and 22 had been assigned to pharmacotherapy. This

sample of participants was 79% Caucasian, and ranged from 18 to 59 years of age (M = 35.30,

SD = 9.83). Participants’ average level of education was moderate (total years of education, M =

16.18, SD = 1.90). Not all participants indicated their total annual household income; however,

75% of participants indicated that their annual household income was more than $20,000 per

year. Participants who completed measures of psychological need fulfillment reported fewer

dysfunctional attitudes at intake than those participants who dropped out of treatment or did not

complete treatment, t (39.95) = -2.4065, p < .05. In comparison to those who completed

measures of psychological need fulfillment, participants who did not complete measures of

psychological need fulfillment reported at intake significantly more depressive symptoms, t

(79.56) = -2.09, p < .05, made more personalization cognitive errors, t (81.65) = -2.39, p < .05,

and were significantly more conscientious, t (62.63) = -2.8529, p < .01.

Chapter 3

Results

Testing Hypothesis 1: Is Psychological Need Fulfillment Significantly Negatively

Correlated with Depression?

Table 1 contains the descriptive statistics for the BMPN, BDI-II, DAS, CEQ, and NEO-

PI-R for all four assessment points, as well as the descriptive statistics for the ECR-R for the first

and last assessment points. Table 2 contains the zero-order correlations for these measures

collapsed across assessment points and participants. In accordance with our first hypothesis,

psychological need fulfillment was significantly and negatively correlated with self-reported

depressive symptoms (Autonomy, r = -.27, p < .05; Competence, r = -.86, p < .01, Relatedness, r

= -.73, p < .01, Composite Psychological Need fulfillment, r = -.78, p < .01). Psychological need

fulfillment was also differentially related to cognitive distortions. Autonomy was negatively

correlated with overgeneralization (r = -.29, p < .05). Competence was negatively correlated with

dysfunctional attitudes (r = -.72, p < .01), selective abstraction (r = -.61, p < .01), and

personalization (r = -.32, p < .05). Relatedness was significantly correlated with dysfunctional

attitudes (r = -.56, p < .01) and selective abstraction (r = -.46, p < .01). Composite psychological

need fulfillment was significantly correlated with dysfunctional attitudes (r = -.53, p < .01),

selective abstraction (r = -.49, p < .01), and overgeneralization (r = -.24, p < .05). In accordance

with the cognitive model of depression (Beck, 1967; Weissman & Beck, 1978), self-reported

depression was significantly correlated with dysfunctional attitudes (r = .56, p < .01) as well as

for the selective abstraction scale from the CEQ (r = .24, p < .05). Contrary to the cognitive

model of depression, no other measure of negative cognitions was significantly correlated with

self-reported depression.

Finally, there were a number of significant intercorrelations among the Big Five

personality traits. Although Costa and McCrae (1992b) have argued that correlations among the

Big Five are method artifacts, the Big Five in the present study were intercorrelated in patterns

that were consistent with previous findings (e.g., John & Srivastava, 1999; Krueger, Caspi,

Moffit, Silva, & McGee, 1996; Yik & Russell, 2001).

Testing Hypothesis 2: Does Psychological Need Fulfillment Increase Over the Course of

Treatment for Depression?

To assess the within-person change in psychological need fulfillment and depression,

conventional growth curve analyses were conducted to test each of the primary hypotheses in the

present study. Growth curve analysis is a technique that utilizes hierarchical linear models (Bryk

& Raudenbush, 1987; Raudenbush, Bryk, Cheong, Congdon, & du Toit, 2004; Singer & Willett,

2003; Snijders & Bosker, 2012; Tasca & Gallop, 2009). Growth curve analysis offers a multitude

of advantages over other analytic techniques (Byrne & Crombie, 2003; Singer & Willet, 2003;

Tasca & Gallop, 2009). Notably, growth curve analysis can accommodate unsystematic missing

data, participants with differing numbers of assessment points, and uneven spacing in the data

collection schedule. Given that such instances of “unbalanced data” (Singer & Willett, 2003, p.

146) are common in ambulatory, outpatient treatment settings, such as the one used in the

present study, growth curve analysis was an integral technique for assessing change in

psychological need fulfillment over the course of treatment for depression. The analyses for the

present study were conducted in R version 3.3.0 (R Development Core Team, 2016) using the

nlme package (Pinheiro, Bates, DebRoy, Sarkar, & R Development Core Team, 2010).

Prior to constructing the proposed growth curve models, we assessed the extent to which

participants’ data were appropriate for conducting multilevel analysis. We calculated the

intraclass correlation coefficients (ICC) for each self-report measure completed by participants in

order to determine the degree of non-independence for participants’ self-reports across all four

assessment points (Hayes, 2006). The ICCs for each variable indexed in the present study are

presented in Table 1. The ICCs presented in Table 1 suggest that there are important

dependencies in the data that need to be accounted for, but that these dependencies are not so

great as to suggest that there is no session-to-session variation to study.

Growth curve models were constructed to examine changes in psychological need

fulfillment across all four assessment points. The results of these models are presented in Table

3. Model 1 represents change in the experience of autonomy over time, Model 2 represents

change in the experience of competence over time, Model 3 represents change in the experience

of relatedness over time, and Model 4 represents change in the experience of overall

psychological need fulfillment over time. The coefficients for Models 1 through 3 suggest that

the typical participant experienced increased autonomy fulfillment, b = 0.04, SE = 0.01, t (109) =

3.48, p < .001, competence fulfillment, b = 0.07, SE = 0.013, t (108) = 5.03, p < .001, and

relatedness fulfillment, b = 0.04, SE = 0.01, t (109) = 3.04, p < .005, across assessment points as

he or she moved through treatment for depression. Similarly, the coefficients for Model 4

suggests that psychological need fulfillment as a whole increased across assessment points, b =

0.05, SE = 0.01, t (108) = 4.86, p < .001. Inspection of the 95% confidence intervals for Models

1 through 4 suggest that autonomy, competence, relatedness, and overall psychological need

fulfillment did not significantly differ from one another in their rates of change across

assessment point.

Testing Hypothesis 3: Do Changes in Psychological Need Fulfillment Relate to Changes in

Depression Across Assessment Points?

Having established that psychological need fulfillment increased over the course of

treatment, we were able to test whether or not changes in psychological need fulfillment were

related to changes in depression severity. Before we could test this hypothesis, it was important

to examine whether or not severity of depression decreased over the course of treatment. Model

5 in Table 3 suggests that depressive symptoms improved over the course of treatment, b = -1.06,

SE = 0.09, t (456) = -12.00, p < .001. Because severity of depression significantly decreased over

the course of treatment, we were able to test whether or not changes in depression severity were

associated with changes in psychological need fulfillment. Models 6 through 9 reflect the

associations between changes in psychological need fulfillment and changes in depression

severity. Autonomy fulfillment, b = -5.86, SE = 1.24, t (107) = -4.72, p < .001, competence

fulfillment, b = -6.97, SE = 0.89, t (106) = -7.80, p < .001, relatedness fulfillment, b =-5.81, SE

=1.19, t (107) = -4.87, p < .001, and overall psychological need fulfillment, b = -9.43, SE = 1.23,

t(106) = -7.65, p < .001, were all significantly and negatively associated with depressive

symptoms. Inspection of the 95% confidence intervals for Models 6 through 9 revealed that the

slopes for autonomy, competence, relatedness, and composite psychological need fulfillment

were not significantly different from one another in terms of predicting change in depressive

symptoms. Because all three psychological needs increased over the course and treatment and

were significantly related to decreased depressive symptoms across assessment points, the

remainder of our analyses were conducted exclusively using the composite for psychological

need fulfillment.

In testing the relationship between psychological need fulfillment and depression severity

over the course of psychotherapy and psychopharmacology, it was essential to account for the

passage of time in our growth curve models. Indeed, the popular adage that time can heal all

wounds is reflected in the ubiquitous issue of regression to the mean, a complicating factor in the

assessment of change (Kazdin, 2007, Lambert and Ogle, 2004). We wanted to account for this

natural change process in our analyses. The results of Model 10 represent the relationship

between psychological need fulfillment and depression severity over the course of our four

assessment points controlling for the impact of the passage of time in the form of number of

weeks since the first assessment point. According to this model, the passage of time was

significantly associated with a decrease in depressive symptoms, b = -0.79, SE = 0.09, t (105) = -

8.58, p < .001. However, after accounting for this effect of time, psychological need fulfillment

remained significantly negatively associated with depression severity over the course of

treatment, b = -6.40, SE = 1.12, t (105) = -5.69, p < .001.

Beyond regression to the mean, we also wanted to demonstrate the incremental validity

of psychological need fulfillment in the prediction of depression severity over and above the

additional changes known to occur over the course of psychotherapy and pharmacotherapy.

Specifically, previous research has shown that personality change can accompany symptom

change over the course of treatment (e.g., Renner Penninx, Peeters, Cuijpers, & Huibers, 2013).

Notably, both attachment style and trait neuroticism have been implicated not only in the

vulnerability to depression but have been shown to change over time (Kinley & Reyno, 2013;

Marmarosh & Tasca, 2013; Maxwell, Tasca, Ritchie, Balfour, & Bissada, 2014; Travis, Bliwise,

Binder, & Horne-Moyer, 2001). We therefore wanted to demonstrate that the observed

association between changes in psychological need fulfillment and changes in depression

severity were not better accounted for by change in these personality variables. In order to test

this, we developed an additional set of growth curve models. Table 5 summarizes the results of

these models. In order to account for the role of change in attachment and neuroticism in

depression severity, we first needed to test whether attachment and neuroticism changed

significantly across assessment points. Models 11, 12, and 13 in Table 3 represent participants’

changes in neuroticism, attachment anxiety, and attachment avoidance over the course of

assessment. The results of these model indicate that only neuroticism, b = -1.00, SE = 0.28, t (67)

= -3.62, p < .001, and attachment anxiety, b = -0.03, SE = 0.01, t (41) = -3.35, p < .01, showed a

significant decrease over the course of treatment. Given the results of Models 11 and 12, we then

constructed a series of models to test if changes in neuroticism and changes in attachment

anxiety were significantly associated with changes in depression severity. Model 14 represents

the association between neuroticism and depression severity and Model 15 represents the

association between attachment anxiety and depression severity. Neuroticism was found to be

significantly associated with depression severity over and above the impact of the passage of

time, b = 0.33, SE = 0.06, t (66) = 5.27, p < .01. Similarly, attachment anxiety, b = 3.904871, SE

= 1.51, t (38) = 2.59, p < .05, was significantly associated with depression severity over and

above the impact of the passage of time.

Having established that both attachment and neuroticism were significantly associated

with depression, two additional models were constructed to test whether psychological need

fulfillment was associated with depression severity over and above attachment and neuroticism.

Model 16 in Table 5 represents the association between psychological need fulfillment and

depression accounting for both the passage of time and neuroticism. The results of this model

suggest that psychological need fulfillment was significantly negatively associated with

depression severity across assessment points over and above the effect of time and changes in

neuroticism, b = -4.826842, SE = 1.2730005, t (42) = -3.79, p < .001. Model 17 in Table 5

represents the relationship between psychological need fulfillment and depression accounting for

both the passage of time and attachment anxiety. The results of this model suggest that

psychological need fulfillment was not significantly associated with depression severity over the

course of treatment after accounting for changes in attachment anxiety and the effect of time, b =

-2.67, SE = 2.054, t (19) = -1.30, p = 0.21.

Given that cognitive change has been shown to be a significant component of treatment

for depression (Garratt, Ingram, Rand, & Sawalani, 2007) we wanted to demonstrate that

psychological need fulfillment could contribute to changes in depressive symptoms above and

beyond this existing process of change. With this mind, and building off of the correlations

between the CEQ selective abstraction scale and depressive symptoms and the correlations

between the DAS and depressive symptoms, we constructed a series models examining the

relative contributions of cognitive change and psychological need fulfillment to changes in

depressive symptoms. Table 6 displays the results of these models. First, we wanted to test

whether or not negative cognitions changed over the course of treatment. The coefficients in

Models 18 and 19 indicate that both dysfunctional attitudes, b = 0.03, SE = 0.01, t (131) = -4.53,

p < .001, and selective abstraction, b = -0.17, SE = 0.0337979, t (131) = -4.89, p < .001)

decreased significantly over the course of treatment. Models 20 and 21 represent that these

decreases in participants’ dysfunctional attitudes, b = 6.60, SE = 1.41, t (128) = 4.67, p < .001,

and cognitive errors, b = 0.93, SE = 0.29, t (128) = 3.25, p < .01, were significantly associated

with decreases in their depressive symptoms over and above the effect of time. Having

demonstrated that decreases in dysfunctional attitudes and decreases in cognitive errors were

associated with decreases in depressive symptoms, we wanted to test whether increases in

psychological need fulfillment contributed to changes in depressive symptoms above and beyond

that of changes in negative cognitions. Models 22 and 23 in Table 6 were constructed to test this.

The results of these models indicated that increases in psychological need fulfillment contributed

to decreases in depressive symptoms over and above the effects of decreases in dysfunctional

attitudes, b = -5.31, SE = 1.03, t (89) = -5.17, p < .001, and selective abstraction, b = -5.33, SE =

0.98, t (90) = -5.44, p < .001.

Testing Hypothesis 4: Is There a Significant Temporal Relationship Between Changes in

Psychological Need Fulfillment and Changes in Depression Severity?

In order to examine the temporal relationship between changes in psychological need

fulfillment and changes in depression severity over the course of CBT and pharmacotherapy for

depression, a series of models were constructed using lagged analyses (Singer and Willett, 2003).

Lagged modeling makes it possible to grapple with issues surrounding state dependence and

reciprocal causation. One concern in the present study was the possibility that participants’

psychological need fulfillment may have been state dependent on the severity of their depressive

symptoms at each assessment point. Alternatively, it is also possible that participants’ depressive

symptoms may have been state dependent on their psychological need fulfillment at each

assessment point. The advantage of lagged modeling is that it allows for testing and confirming

the direction of associations. Although lagged models cannot determine the causal pathways in

longitudinal relationships, a conclusion reserved for the addition of experimental controls,

lagging predictor variables does allow one to establish the temporal precedence of an association.

According to Singer and Willett (2003), examining the temporal precedence of an association

requires lagged models to be constructed based on theory. SDT maintains that psychological

need fulfillment is integral to psychological health and growth. As noted previously, the existing

literature surveying the relationship between psychological need fulfillment, internalization, and

psychopathology suggests that environments which facilitate psychological need fulfillment are

what lead to psychological health and growth (Deci & Ryan, 2000; Deci & Ryan, 2008; Ryan,

1995; Ryan, Deci, & Vansteenkiste, 2016). Given the assumption that psychological need

fulfillment is a prerequisite for health, it is possible that participants in the present study

experienced changes in their psychological need fulfillment prior to experiencing changes in

their depressive symptoms. Alternatively, SDT maintains that psychological need fulfillment

does not abide by a drive reduction model typically associated with conceptualizations of needs

(Hull, 1943). Specifically, individuals are not impelled to experience autonomy, competence, and

relatedness in order to satisfy or reduce a drive in the same way they are impelled to eat in order

to reduce hunger. Rather, psychological need fulfillment is drive-inducing (Deci & Ryan, 2000;

Ryan, Deci, & Vansteenkiste, 2016), where the experiences of autonomy, competence, and

relatedness energize motivation and broaden individuals’ capacities to seek out additional

psychological need fulfillment. In this vein, it is also possible that participants in the present

study experienced changes in their depressive symptoms prior to experiencing changes in

psychological need fulfillment.

Given that SDT proposes a bidirectional relationship between psychological need

fulfillment and psychological health, we constructed two lagged models to test this. The results

of these models are presented in Table 7. Model 24 in Table 6 represents the association between

changes in psychological need fulfillment and subsequent changes in depressive symptoms at a

lag of one assessment point. The results of this model indicate that there was a significant

negative association between changes in psychological need fulfillment and subsequent changes

in depressive symptoms, b = -4.32, SE = 1.63, t(64) = -2.65, p < .05. Model 25 in Table 7

represents the converse association: The association between changes in depressive symptoms

and subsequent changes in psychological need fulfillment. The result of this model suggest that

there was a significant negative relationship between changes in depressive symptoms and

subsequent changes in psychological need fulfillment, b = -0.03, SE = 0.01, t (79) = -2.73, p <

.01. Collectively, these two models indicate that participants’ depressive symptoms not only

decreased prior to associated increases in their psychological need fulfillment, but also that

participants’ experience of psychological need fulfillment increased prior to associated decreases

in their depressive symptoms. Models 26 and 27 in Table 7 were constructed to test whether

these temporal relationships between psychological need fulfillment and depression severity

remained significant after accounting for the effect of time. The results of these models indicated

that neither of these lagged associations were significant over and above the passage of time.

Testing Hypothesis 5: Do Other Personality Variables Impact the Temporal Relationships

Between Changes in Psychological Need Fulfillment and Changes in Depression Severity?

Beyond exploration of the temporal relationship between changes in psychological need

fulfillment and changes in depressive symptoms, we wanted to explore how both neuroticism

and attachment contribute to this relationship. In this vein we constructed an additional set of

models using neuroticism and attachment anxiety as covariates in the temporal association

between psychological need fulfillment and depression severity. First, given the bidirectional

temporal relationship between psychological need fulfillment and depression severity, it was

necessary to examine psychological need fulfillment and its respective relationships with

neuroticism and attachment anxiety. Models 28 and 29 in Table 8 were constructed to test these

respective relationships. The results of these models indicated that participants’ changes

neuroticism, b = -0.03, SE = 0.008, t (43) = -3.55, p < .01, and changes in attachment anxiety, b

= -0.57, SE = 0.16, t (21) = -3.68, p < .01) were both significantly and negatively associated with

their change in psychological need fulfillment across assessment points over and above the effect

of time.

Given the findings suggested by these models, it was possible to explore the relative

contributions of both changes in psychological need fulfillment to subsequent changes in

depressive symptoms, and changes in depressive symptoms to subsequent changes in

psychological need fulfillment above and beyond that of neuroticism and attachment anxiety.

Models 30 and 31 were constructed to test the association between participants’ increases in

psychological need fulfilment and subsequent decreases in depressive symptoms, accounting for

their decreases in both neuroticism and attachment anxiety over the course treatment,

respectively. The results of both of these models indicate that the association between increases

in psychological need fulfillment and subsequent decreases in depressive symptoms was no

longer significant after statistically controlling for changes in neuroticism, b = 1.03, SE = 2.90, t

(9) = 0.36, p = 0.73, and attachment anxiety, b = -0.22, SE = 6.13, t (13) = -0.04, p = 0.97.

Models 32 and 33 test the reverse of this association: The relationship between participants’

decreases in depressive symptoms and subsequent increases in psychological need fulfillment,

after accounting statistically for the effects of neuroticism and attachment anxiety. The

coefficients in both of these models demonstrate that the association between decreases in

depressive symptoms and subsequent increases in psychological need fulfillment was no longer

significant after accounting statistically for the effects of neuroticism, b = 0.003, SE = 0.017,

t(28) = 0.16, p = 0.8777, and attachment anxiety, b = -0.05, SE = 0.03, t(13) = -1.76, p = .48).

Together, these four models indicate that the bidirectional temporal relationship between changes

in psychological need fulfillment and changes in depressive symptoms were not significant over

and above change in personality variable over the course of treatment.

Testing Hypothesis 6: Is the Relationships Between Increases in Psychological Need

Fulfillment and Decreases in Depression Severity Mediated by Change in Negative

Cognitions?

We hypothesized that increases in psychological need fulfillment would be associated

with a decrease in negative cognitions, and that increases in psychological need fulfillment

would indirectly predict decreases in depressive symptoms through reduced negative cognitions.

Given the zero-order correlations presented in Table 2, we chose to focus on the DAS as our

primary index of negative cognitions. In order to test this hypothesis, we implemented a variant

of the causal steps approach (Baron & Kenny, 1986) amended for 1-1-1 multilevel mediation

(Zhang, Zyphur, & Preacher, 2009), because all of the predictor (i.e., psychological need

fulfillment), mediator (i.e., negative cognitions), and outcome variables (i.e., depression severity)

varied across all participants. Because this type of mediation model confounds Level 1 variables

with Level 2 variables, we included both the aggregated and within-person-mean-centered values

for all relevant predictors (Zhang, Zyphur, & Preacher, 2009). All multilevel models used an

unstructured covariance matrix and the between-within method of estimating degrees of

freedom.

Three multilevel models were constructed. First, participants’ negative cognitions were

modeled as a function of aggregated psychological need fulfillment and within-person-mean-

centered psychological need fulfillment, with a random slope for the influence of within-person-

mean-centered psychological need fulfillment estimated for each participant. The results of this

model are represented by Model 34 in Table 9. This model revealed a significant negative effect

of aggregated psychological need fulfillment on participants’ negative cognitions, b = -0.50, SE

= 0.12, t (47) = -4.29, p < .001), and a significant effect of within-person-mean-centered

psychological need fulfillment on participants’ negative cognitions, b = -0.42, SE = 0.09, t (93) =

-4.94, p < .001. At the lowest level, this first model reduced prediction error by a very large

amount, R21 = .70; at the second level, this model also reduced prediction error by a large

amount, R22 = .77. Second, change in depressive symptoms were modelled as a function of

aggregated psychological need fulfillment and within-person-mean-centered psychological need

fulfillment, with a random intercept for each participant. Model 35 in Table 9 depicts the results

of this model. This model revealed a significant negative effect of aggregated psychological need

fulfillment on depressive symptoms, b = -9.01, SE = 1.13, t (49) = -7.95, p < .001, and a

significant effect of within-person-mean-centered psychological need fulfillment on depressive

symptoms, b = -9.33, SE = 1.23, t (106) = -7.61, p < .001. At the lowest level, the second model

reduced prediction error by a large amount, R21 = .47; at the second level, this model also

reduced prediction error by a large amount, R22 = .57. Finally, depressive symptoms were

modeled as a function of aggregated psychological need fulfillment, within-person-mean-

centered psychological need fulfillment, aggregated negative cognitions, and within-person-

mean-centered negative cognitions, with a random slope for the influence of within-person-

mean-centered negative cognitions for each participant. The final model, represented by Model

36 in Table 9, revealed a significant effect of aggregated psychological need fulfillment on

depressive symptoms, b = -7.69, SE = 1.22, t (46) = -6.32, p < .001, a significant effect of

within-person-mean-centered psychological need fulfillment on depressive symptoms, b = -6.61,

SE = 1.11, t (90) = -5.97, p < .001, a nonsignificant effect of aggregated negative cognitions on

depressive symptoms, b = 1.79, SE = 1.25, t (46) = 1.43, p = 0.16, and a significant effect of

within-person-mean-centered negative cognitions on depressive symptoms, b = 6.73, SE = 1.65, t

(90) = 4.07, p < .001. At the lowest level, the final model reduced prediction error by a large

amount, R21 = .54; at the second level, the final model also reduced prediction error by a large

amount, R22 = .57. According to Zhang, Zyphur, and Preacher (2009), the criteria for testing

mediation was observed at Level 1 because the effect of within-person-mean-centered

psychological need fulfillment was significant in the first model, b = -0.42, SE = 0.09, t (93) = -

4.94, p < .001, and the effects of within-person-mean-centered psychological need fulfillment, b

= -6.61, SE = 1.11, t (90) = -5.97, p < .001, and within-person-mean-centered negative

cognitions, b = 6.73, SE = 1.65, t (90) = 4.07, p < .001, were significant in the final model.

To test for mediation, first we had to ascertain how consistent our mediation model was

across the Level 2 groups and so we computed the population covariance of the random slopes of

the indirect path from psychological need fulfillment to negative cognitions, σab = -0.018. A

significance test of the correlation between the random slopes indicated that the population

covariance did not differ from zero, rab = -0.04, p = 0.78, which implies that the indirect effect of

psychological need fulfillment on depressive symptoms was consistent for all participants. The

population covariance was used to conduct a Sobel Test with the Aroian correction, ab = -2.83,

Sobel z = -1.71, p = 0.09, suggesting that the indirect effect was not significantly different from

zero. Thus, change in negative cognitions was not found to mediate the association between

changes in psychological need fulfillment and changes in depression severity. The complete

results our proposed mediation model are depicted in Figure 1.

Testing Hypothesis 7: Does the Temporal Relationships Between Changes in Psychological

Need Fulfillment and Changes in Depression Severity Differ Across Treatment and Client

Variables?

Participants’ random assignment to pharmacotherapy and cognitive therapy provided us

with the opportunity to compare the temporal relationship between changes in psychological

need fulfillment and depression severity across treatment conditions. To test for the effect of

treatment group, participants who were randomly assigned to pharmacotherapy were dummy

coded with 1 and participants who were random assigned to cognitive therapy were dummy

coded with a 0.

We first tested two models to examine if treatment group moderated overall change in

psychological need fulfillment and depressive symptoms over the course of treatment. Models 37

and 38 depict the results of these tests. According to the coefficients of these models, treatment

group did not moderate overall change in psychological need fulfillment, b = -0.03, SE = 0.02, t

(107) = -1.33, p = 0.18, nor did it moderate overall change in depressive symptoms, b = 0.21, SE

= 0.13, t (455) = 1.52, p = 0.13.

Models 39 and 40 examine the effects of treatment group on the association between

changes in psychological need fulfillment and subsequent changes in depressive symptoms, and

the effects of treatment group on the association between changes in depressive symptom and

subsequent changes in psychological need fulfillment. In accordance with our hypothesis, there

was a significant interaction effect for treatment group in both lagged models. Specifically,

participants receiving cognitive therapy demonstrated stronger associations between increases in

psychological need fulfillment and subsequent changes in depressive symptoms, b = 7.27, SE =

2.58, t (62) = 2.82, p < .01), as well as stronger associations between decreases in depressive

symptoms and subsequent increases in psychological need fulfillment, b = 0.05, SE = 0.02, t (77)

= 2.88, p < .01. Examination of the simple slopes for Model 39 revealed a significant effect for

lagged psychological need fulfillment on subsequent depressive symptoms in the cognitive

therapy condition, b = -5.90, SE = 1.34, t (48) = -4.41, p < .01, and a nonsignificant effect for

lagged psychological need fulfillment on subsequent decreases in depressive symptoms in the

antidepressant medication condition, b = 1.37, SE =1.76, t (21) = 0.78, p = 0.44. Similarly,

examination of the simple slopes for Model 40 revealed a significant effect for lagged depressive

symptoms on subsequent psychological need fulfillment in the cognitive therapy condition, b = -

0.04, SE = 0.01, t (48) = -2.78, p < .01, and a nonsignificant effect for lagged depressive

symptoms on psychological need fulfillment in the antidepressant medication condition b = .01,

SE = -1.43, t (48) = -0.01, p = 0.50. Indeed, the reciprocal lagged relationship between changes

in psychological need fulfillment and changes in depressive symptoms was more robust for

participants in the cognitive therapy condition than for participants in the antidepressant

medication condition.

In addition to testing differences across treatment groups, we also constructed models to

test for the effects of client variables such as sex, number of years of education, and income on

changes in psychological need fulfillment. The results of these models indicated that increases in

psychological need fulfillment over the course of treatment did not differ with respect to sex, b =

-0.004, SE = 0.02, t (107) = -0.23, p = 0.81; number of years of education, b = -0.004, SE = 0.01,

t (107) = -0.78, p = 0.44; or income, b = 0.04, SE = 0.02, t (107) = 1.60, p = 0.11. These findings

indicate that increases in psychological need fulfillment over the course of treatment were

consistent across clients of varying backgrounds.

Chapter 4

Discussion

The present study sought to examine the relationship between changes in psychological need

fulfillment and changes in depressive symptoms over the course of cognitive therapy and ADM.

Our findings indicated that over the course of treatment, participants showed increases in

autonomy, competence, and relatedness, and that these increases in need fulfillment were

commensurate across clients with varying backgrounds. This increase in participants’

psychological need fulfilment was significantly and negatively associated with depressive

symptoms over the course of treatment. This relationship was also significant above and beyond

the passage of time as well as changes in neuroticism over the course of treatment; changes in

dysfunctional attitudes; changes in cognitive errors; but not changes in attachment. Moreover,

lagged growth curve models indicated that the relationship between changes in psychological

need fulfillment and changes in depressive symptoms over time is bidirectional. Over the course

of psychotherapy and ADM, not only did increases in psychological need fulfillment predict

subsequent decreases in depressive symptoms, but also decreases in depressive symptoms

predicted subsequent increases in psychological need fulfillment. However, this bidirectional

relationship was no longer significant after accounting for the passage of time, changes in

neuroticism, or changes in attachment. This bidirectional relationship did not differ between

males or females. However, it was more pronounced in participants who had been randomly

assigned to ADM. Given the inconclusive specificity of cognitive change in treatments for

depression, we had hypothesized that the observed relationship between increases in

psychological need fulfillment and decreases in depressive symptoms would be mediated by a

reduction in negative cognitions. Contrary to our hypothesis, however, the indirect effect of

psychological need fulfillment on changes in depressive symptoms via change in negative

cognitions was nonsignificant.

Changes in Psychological Need Fulfillment Over Time

In the present study, participants experienced increases in autonomy, competence, and

relatedness over the course of four assessment points during treatment for depression. This

finding was predicted based on previous research that has identified changes in patients’

experiences of autonomy over the course of four weeks of cognitive behavioral therapy (Dwyer,

Hornsey, Smith, Oei, & Dingle, 2011). The present study extends these findings, demonstrating

that not only does autonomy increase over the course of treatment for depression, but so does

competence and relatedness. Moreover, the present study extends these changes in psychological

need fulfillment further by demonstrating that autonomy, competence, and relatedness increase

over the course of both cognitive therapy and ADM. The finding that psychological need

fulfillment increases over the course of treatment is also meaningful because it confirms much

about what has largely been assumed in the literature bridging the treatment of psychopathology

and SDT. As previously mentioned, much of the work bridging these two areas of research

places emphasis on qualities of motivation and internalization and how they impact treatment

outcomes, presupposing the fulfillment or frustration of psychological needs. The present study

therefore adds to a growing body of research which documents the role of changes in

psychological need fulfillment in understanding psychopathology and its treatment (Dwyer,

Hornsey, Smith, Oei, & Dingle, 2011; Verstuyf, Vansteenkiste, & Soenens, 2012; Verstuyf,

Vansteenkiste, Sonenes, Boone, & Mouratidis, 2013).

The Relationship Between Changes in Psychological Need Fulfillment and Changes in

Depressive Symptoms

Having identified significant changes in participants’ psychological need fulfillment over

the course of four assessment points, it was possible to explore the relationship between changes

in psychological need fulfillment and changes in depressive symptoms. Aligning with the

findings discussed above, the results indicated that increases in autonomy, competence, and

relatedness were all significantly and negatively associated with changes in depressive

symptoms. All three psychological needs did not significantly differ from one another in their

associations with changes in depressive symptoms, reinforcing a major tenet of SDT: autonomy,

competence, and relatedness are equally vital in contributing psychological growth and health

(Deci & Ryan, 2000; Deci & Ryan, 2008; Ryan, 1995). Moreover, this pattern of results

remained significant when accounting for the impacts of time, neuroticism, attachment anxiety,

dysfunctional attitudes, and selective abstraction.

The present study design was not experimental, preventing any attempt to evaluate the

causal pathways that characterize the association between changes in psychological need

fulfillment and changes in depressive symptoms. However, the repeated assessment of theses

variables of interest did allow us to explore the temporal precedence of changes in one relative to

the other. Specifically, the present design allowed for the construction of lagged models to

empirically determine whether shifts in one variable preceded shifts in another. The first set of

lagged models tested whether changes in psychological need fulfillment temporally preceded

changes in depressive symptoms. The results of this model were significant, indicating that a

relationship was observed between participants starting to feel more autonomous, more

competent, and more related and ensuing changes in their depressive symptoms. The second set

of lagged models tested the reflection of this association: whether changes in depressive

symptoms temporally preceded changes in psychological need fulfillment. This model was also

significant; as participants experienced fewer depressive symptoms, they subsequently began to

feel more autonomous, more competent, and more related. The bidirectional relationship

between changes in psychological need fulfillment and depressive symptoms is in accordance

with SDT’s concept of psychological needs as drive-inducing resources (Deci & Ryan, 1985;

Deci & Ryan, 2000). From this perspective, psychological need fulfillment is energizing and

mobilizes individuals to seek out additional opportunities for psychological need fulfillment,

which further promote growth and health (Deci & Ryan, 1985).

Interestingly, the present study found that treatment group moderated this bidirectional

temporal association. The results of the treatment group interaction models that were constructed

suggest that the bidirectional association between changes in psychological need fulfillment and

changes in depressive symptoms was stronger for participants who had been randomly assigned

to cognitive therapy for treatment. Why would this temporal relationship be stronger for

participants receiving CBT than for participants receiving ADM? In other words, what is it about

cognitive therapy that would strengthen the effect of psychological need fulfillment on

subsequent decreases in depressive symptoms, and vice versa, approximately one month later?

One potential explanation is that the client-therapist relationship may cultivate openness, self-

congruence, and self-awareness of one’s experience, defining aspects of unified self-functioning

and the integrative process (Fournier, Di Domenico, Weststrate, Quitasol, & Dong, 2016;

Rogers, 1963; Weinstein, Przybylski, & Ryan, 2012, 2013). Across a myriad of traditions (see

Ryan, 1995), functioning in an integrated manner entails enhanced access to motives, emotions,

and meanings behind one’s actions. Indeed, an integral component of the CBT protocol used in

the present study required participants to reflect on and evaluate their current experiences and

problems each week in the context of a thought record. In each session, participants were

encouraged to reflect on their experience over the previous week and examine thoughts,

emotions, and behaviors in a supportive therapeutic context, with the intention of identifying

maladaptive patterns. It is possible that lagged changes in both psychological need fulfillment

and depressive symptoms interacted with this treatment component to catalyze participants’

tendencies toward integration, enhancing both vitality and wellness (Ryan & Deci, 2008).

Testing the Role of Negative Cognitions in the Relationship Between Changes in

Psychological Need Fulfillment and Depressive Symptoms

After establishing the association between changes in psychological need fulfillment and

changes in depressive symptoms, we sought to test whether the effect for changes in

psychological need fulfillment on changes in depressive symptoms was mediated by changes in

negative cognitions. Contrary to our hypothesis, the indirect effect of this mediation model

proved to be non-significant. Given that our initial power analysis for this model had been

conducted without the complete dataset in hand, we recalculated power for this analysis using

the updated sample size using the powerMediation package in R (Qiu, 2015). This updated

power analysis revealed that we only had 57% power to observe the indirect effect of our model,

ab = -2.83.

Limitations

The present study is not without limitations. First, assessment of psychological need

fulfillment was not originally part of the larger research project for which the participants of the

current study were recruited for. Thus, our analyses were conducted with only nearly half of the

potential participants recruited. Moreover, participants who completed measures of

psychological need fulfillment were significantly different from those who did not. Although this

may be an artifact of introducing a measure much later into the data collection process, the

participants included in the present study reported fewer depressive symptoms, made fewer

personalization cognitive errors, and were significantly less conscientious compared to those

who were not. Related to the limitations of the sample in the present study, our updated power

analysis revealed that the subsample of participants who completed indices of psychological

need fulfillment did not provide sufficient power to thoroughly test the indirect effect of reduced

negative cognitions on the association between increases in psychological need fulfillment and

decreases in depressive symptoms. Finally, the present study collected data across four

assessment points, which varied in the length of time that transpired between each assessment

point. Although this allows for maximal spacing for exploring change, participants could only

end up with a maximum of four data points for most measures. This prevented us from

constructing lagged analyses beyond a single assessment to further explore the temporal

relationship between psychological need fulfillment and depressive symptoms.

Future Directions

One possible future direction for research exploring the relationship between

psychological need fulfillment and depressive symptoms concerns exploring the various contexts

in which changes in psychological need fulfillment and changes in depression are embedded.

Although a bidirectional relationship between changes in need fulfillment and changes in

depressive symptoms is commensurate with SDT, it would have been interesting to explore the

contexts in which one precedes the other. This would have been especially interesting to explore

given the finding that that bidirectional association between psychological need fulfillment and

depressive symptoms was stronger for participants in the cognitive therapy condition.

Unfortunately, the present study did not employ any form of event-contingent or diary-based

form of recording (e.g. Funder, 2016; Moskowitz, 1994) to relate participants’ changes in

psychological need fulfillment and changes in depressive symptoms to specific events in their

environments. Future research may benefit from exploring such change in the context of multiple

environments. Given that increases in psychological need fulfillment appear to have a non-

specific role in treatments for depression, it would also be beneficial for future research to

explore how such changes in need fulfillment compare to other non-specific factors, such as

therapeutic alliance (e.g., Gaston, 1990) and autonomous motivation (McBride, Zuroff, Ravitz,

Koestner, Moskowitz, Quilty, & Bagby, 2010; Ryan & Deci, 2008; Zuroff, Koestner,

Moskowitz, McBride, & Bagby, 2012). Moreover, given that the cultivation of autonomous

motivation assumes prior psychological need fulfillment, and that autonomous motivation is an

integral part of the integrative process (Deci & Ryan, 2000; Ryan & Deci, 2008), prospective

research should seek to confirm the causal relationship between psychological need fulfillment

and autonomous motivation.

Conclusion

The present study is one of few to explore the relationship between changes in

psychological need fulfilment and psychological symptoms, specifically depressive symptoms.

Over the course of treatment for depression, participants demonstrated that changes in

psychological need fulfillment have not only a reliable trajectory within and across individuals,

but also that such changes influence one another bidirectionally. In the present study, changes in

psychological need fulfillment were found to be associated with changes in depressive symptoms

over an above the course of time, personality constructs (i.e., neuroticism and attachment

anxiety), and even negative cognitions (i.e., dysfunctional attitudes and selective abstraction). In

this vein, the present study highlights psychological need fulfillment as a non-specific factor

promoting healthy change across two treatment modalities. The temporal relationship between

increases in psychological need fulfillment and decreases in depressive symptoms was also

found to work reciprocally, reaffirming SDT’s conceptualization of psychological needs as

drive-inducing nutrients that fuel a cycle of psychological growth. Moreover, this reciprocal

relationship was found to be more robust in cognitive therapy than psychopharmacology. Indeed,

when it comes to maximizing the effects of psychological need fulfillment in the treatment for

depression, it would seem that wilted flowers flourish most when tended with the nurturing

hands of a gardener.

31

References

Assor, A., & Tal, K. (2012). When parents’ affection depends on child'