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characterized the earliest days of the field. There is also a strong connection between theory and technique that

Available online at www.sciencedirect.com

ScienceDiBehavior Therapy 44 (20Keywords: theory; cognitive behavior therapy; acceptance andcommitment therapy; contextual behavioral science

There is nothing so practical as a good theory. Lewin (1951, p. 169)

For years, scholars of the family of psychotherapy

that a reading of the current literature on behaviortherapy suggests that the field is at risk of losing itsmomentum in a preoccupation with technologicalrefinements at the expense of theoretical develop-ments (Ross, 1985, p. 195). Wilson and Franks(1982) similarly decried the rapid proliferation ofclinical techniques decoupled from theory, suggest-ing that this trend could ultimately sow the seeds ofthe fields demise. More recently, Beck (2012) notedthat ". . . the robustness of a therapy is based on theCBT over the past decade, along with the dissemination ofstatistical innovations among psychotherapy researchers, havegiven new life to this old issue.We argue that theory likely doesmatter to clinical outcomes, and we outline the future researchthat would be needed to address this conjecture.

of CBT approaches. In his 1984 presidential addressof the Association for Advancement of BehaviorTherapy (now the Association for Behavioral andCognitive Therapies; ABCT), Alan Ross lamentedwidespread assumption that a greater working knowledge oftheory will lead to better clinical outcomes, although there iscurrently very little hard evidence to support this claim. Wesuggest that the rise of so-called third generationmodels of

characterized the fields early days, and that arenewed focus on such links will lead to more rapidand reliable advances in our understanding, devel-opment, testing, implementation, and disseminationThe Importance of Theory iA Perspective of Conte

James DDrexel

BrandonButler Hospital/Alpert Medi

Evan MDrexel

For the past 30 years, generations of scholars of cognitivebehavior therapy (CBT) have expressed concern that clinicalpractice has abandoned the close links with theory thatapproaches known under the broad umbrella of

Address correspondence to James D. Herbert, Ph.D., DrexelUniversity, Department of Psychology, 3141 Chestnut St., Stratton119, Philadelphia, PA 19104; e-mail: james.herbert@drexel.edu.0005-7894/44/580-591/$1.00/0 2013 Association for Behavioral and Cognitive Therapies. Published byElsevier Ltd. All rights reserved.ognitive Behavior Therapy:ual Behavioral Science

erbertiversity

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cognitive behavior therapy (CBT) have been callingfor an increased focus on the theories that underlieapplied technologies. The common theme of theseappeals is that there has been a gradual erosion of the

rect13) 580591

www.elsevier.com/locate/btcomplexity and richness of the underlying theory. Arobust theory, for example, can generate newtherapies or can draw on existing therapies that areconsistent with it" (p. 6). David and Montgomery(2011) proposed a new framework for definingevidence-based psychological practice that pri-oritizes the level of empirical support of the theory

581theory in cbtsupporting a treatment. Recommendations thatclinicians should develop better working knowledgeof the theories underlying CBTs often are presentedduring discussions of how to maximize treatmentoutcomes, prevent treatment failures, and amelioratetreatment resistance in complex cases (Foa &Emmelkamp, 1983;McKay, Abramowitz, & Taylor,2010; Whisman, 2008). An interorganizational taskforce led by the ABCT recently issued a report ondoctoral training in cognitive behavioral psychologyinwhich training in theory and even thephilosophyofscience underlying CBTs was emphasized (Klepacet al., 2012).The call for greater emphasis on theory within

CBT therefore spans the generations. In fact, if onewere tomask the author anddate, itwould be hard todistinguish writings on this subject made by contem-porary authors from thosewritten over 30 years ago.There appears to exist a widespread assumptionamong many clinicians and researchers alike thatbetter knowledge of theory will bear fruit in terms ofimproved clinical outcomes across a number of con-texts. Although this notion has considerable facevalidity, there is a paucity of research that has directlyevaluated it.Historically, the desire for empirically supported

treatments led to testing psychotherapies in controlledclinical trials to determine their efficacy, a procedureborrowed from other medical treatments. Forexample, the seminal study known as the NationalInstitute ofMental Health's Treatment of DepressionCollaborative Research Program (Elkin et al., 1995)randomized patients with major depression to cog-nitive therapy, interpersonal psychotherapy, or anti-depressant medication, and ushered in a new era ofevaluating psychotherapies in large-scale and meth-odologically rigorous clinical trials. CBTs, giventheir empirical basis, inherent structure, and time-limited nature, were particularly well-suited fortesting in clinical trials. As a result, CBTs becamehighly manualized in an effort to ensure treatmentfidelity, an important component of the internalvalidity of such trials (Addis & Krasnow, 2000).Originally CBTs were more principle-driven andtheory-dependent in the way that they were concep-tualized and implemented (e.g.,Goldfried&Davison,1994). With the growth of clinical trials during the1970s and 80s, however, treatment manuals beganto focus more on how to implement specific CBTtechniques and strategies and less on interventionsderived from case conceptualization based on theideographic assessment of the patient guided by anunderlying theory. We are unaware of data directlycomparing the level of theoretical knowledge of earlypractitioners of behavior therapy relative to modernCBT clinicians. Nevertheless, even a casual compar-ison of the fields early books and journals targetingclinicians relative to later works reveals a starkcontrast in the degree of emphasis on theory.As the evidence base for CBTs expanded due to the

rapid accumulation of supportive efficacy research,the problem of how best to implement and dissem-inate the treatments emerged as a pressing problem(Addis, 2006). Although novel psychotherapiestypically begin in complex and sophisticated formsbecause they are created by experienced researchersand clinicians, disseminating them to communitypractitioners exerts pressure to simplify them asmuch as possible. It is easier to train nonexperttherapists to implement a set of standard techniquesthan it is to train them to comprehend an underlyingtheory. Once standard techniques are mastered,clinicians well versed in theory can potentiallyapply their knowledge to unique cases in order todeduce tailored interventions.The picture is complicated further because there is

no single CBT model, nor single theory underlying it.CBT is a broad umbrella term that encompasses arange of distinct therapy models (Herbert & Forman,2011). These models share certain features, while alsohavingdistinct characteristics. The theories underlyingthese approaches likewise share certain commonalities(e.g., traditional respondent and operant conditioningprinciples), while also positing unique features.More-over, key theoretical issues, such as the best way tounderstand the role of cognitive processes in treat-ment, are currently the subject of intense professionaldebate (Hofmann, 2008; Longmore&Worrell, 2007;Worrell & Longmore, 2008), and have undergoneconsiderable changes over the years (Beck, 2005).We believe that two developments over the past

decade have added a new twist to the long-standingquestion about the role of theory in guidingpsychotherapy. First, the question has been reinvigo-rated by the rise of the so-called third wave (alsoknown as third generation) models of CBT. Thesenewer CBT approaches such as Mindfulness-BasedCognitive Therapy (Segal, Williams, & Teasdale,2002), Dialectical Behavior Therapy (Linehan, 1993),and especially Acceptance and Commitment Therapy(ACT; Hayes, Strosahl, & Wilson, 2011) eschew asimplistic focus on specific techniques and strategies infavor of increased attention to the putative principlesunderlying behavior change, which are in turn linkedwith basic psychological theories (Ablon, Levy, &Katenstein, 2006; Hayes, 2004; Rosen & Davison,2003). Second, psychotherapy treatment researchershave increasingly focused on therapy processes usingcomponent analysis studies (Borkovec & Sibrava,2005; Lohr, DeMaio, & McGlynn, 2003) and theidentification of treatment-related mediators andmoderators (Kraemer, Wilson, Fairburn, & Agras,

2002). These two developments have had synergisticeffects, further stimulating discussion of the role oftheory in CBTs. For example, calls by proponentsof third-generation approaches to focus on psycho-therapy processes, rather thanmerely techniques, hasaccelerated research on the mechanisms of action in

What Is Theory?The word theory derives from the Greek theoria,meaning looking at, viewing, beholding, or con-templation (Oxford English Dictionary Online,

582 herbert et al .CBTs more generally. Simultaneously, more accessi-ble and advanced statistical procedures have made iteasier for researchers to investigate mechanisms ofchange, and have stimulated therapy innovators toevaluate the proposed theories underlying theirapproaches. Although the argument that under-standing theory will improve clinical outcomes hasbeen a perennial theme in the field, innovationsassociated with the development of third-generationmodels of CBT, along with the development of newstatistical tools, have brought this issue back into theforefront of discussion.We should not lose sight of the fact that proponents

of the utility of theory are often themselves theoreti-cians and may thus overestimate the importance oftheory. The extent to which improving clinicians'theoretical knowledge does, in fact, result in improvedclinical outcomes is ultimately an empirical question.The best approach to evaluating this supposition isitself complicated and will require clarification of anumber of related issues. First and foremost, are therecompelling reasons to hypothesize that knowledge oftheory will, in fact, improve outcomes? Second, whatevidence, if any, currently supports the notion thatgaining a better theoretical understanding of apsychotherapeutic approach enhances outcomesover and above mere technical knowledge of theapproach? Third, even if theoretical knowledge isfound to accrue incremental benefits, does it pass acost-benefit test? Fourth, if such efforts can indeed bedemonstrated to be cost effective, how much theoret-ical knowledge and training is needed to improveoutcomes? Fifth, which theory or theories should beprioritized? Presumably, some theories have greaterbreadth, depth, precision, explanatory power, andincremental efficacy than others, making them moreuseful guides. Sixth, to what degree is it necessarysimply to understand theory in abstract terms versusbeing able to apply it to individual cases?And seventh,and perhaps most fundamentally, what exactly do wemean by the term theory? We will briefly explorethese and related questions regarding the role oftheory, using ACT in particular as a case in point.1

1We focus on ACT as the prototypical third-generationmodel of CBT for two reasons. First, it has received the mostresearch attention to date of these various approaches. Second, aselaborated below, it is based on a well-developed theory, and itstrongly emphasizes the link between theory and technique. Theemphasis on ACT is not meant to imply that other approaches arenot also theoretically grounded.2012). This sense of perspective is reflected in itsmodern use in the context of psychotherapy as aset of basic concepts and principles, along withstatements that describe their interactions, whichcan be used to describe, predict, and guideintervention with respect to specific behavioraland psychological phenomena. The concepts thatare the building blocks of theories can be general-izations directly derived from sensory experience(e.g., reinforcement), or abstractions of thesegeneralizations that are linguistically coherent withother concepts, but are farther removed fromspecific perceptual experiences (e.g., recovery orwell-being). Moreover, although some conceptsfit the classical Aristotelian definition of meetingnecessary and sufficient criteria, more commonlypsychological concepts have indistinct and over-lapping boundaries, as described by prototypetheory (Rosch, 1983). Psychological theories canrange from the very general and abstract to themore focused and applied. In fact, one can thinkof theories along a continuum, linking basicphilosophical assumptions on the one hand withspecific assessment and intervention techniques onthe other.For example, consider the theory underlying

Becks cognitive therapy (CT; Beck, 1979).2 At themost abstract level are its philosophical roots which,like most mainstream psychology, are grounded in aphilosophy of science known as elemental realism.From this perspective, the world exists independentof our senses, and comes predivided into units. Thepurpose of science is to build increasingly moreaccurate models that describe this world, thateffectively carve nature at its joints, and that describehow these constituent pieces interact. In this sense,statements about the world can be objectively true orfalse in terms of how well they model underlyingreality. Following from these philosophical assump-tions, CT theory posits various concepts such asschemas, conditional assumptions, and automaticthoughts, which are believed to interact with currentenvironmental conditions to result in emotions andbehavior. In turn, models of specific clinical phe-nomena such as depression or panic disorder arebuilt from these more general concepts. Clinical

2 A detailed analysis of the theory underlying CT and how it issimilar to and different from ACT theory is beyond the scope ofthis analysis. Interested readers are referred to Dozois and Beck(2011), Forman and Herbert (2009), and Herbert and Forman(2013).

583theory in cbtstrategies and techniques, which may be derivedfrom the basic theoretical concepts, are guided bythese clinical models.ACT is similarly undergirded by philosophical

assumptions. In fact, examining ACTs philosophicalassumptions helps to bring into relief the assumptionsof CT described above, which are often overlooked ortaken for granted. In contrast to CT, ACT is based ona pragmatic philosophy of science known as func-tional contextualism (Hayes, 1993). This perspectivesidesteps ontological questions about the ultimatenature of reality in favor of a pragmatic focus onwhatworks in a given context (Barnes-Holmes, 2000).There is no assumption that the world comespredivided into constituent parts. Rather, all classifi-cations, concepts, and descriptions ofmechanisms areviewed as social constructions and are evaluated withrespect to how well they work with respect to adefined goal. A concept that is true (in the sense ofbeing useful) in one context may therefore not betrue in another. That is, the world is textured insuch away that some theorieswork better than otherswith regard to a given goal. This philosophy forms thebasis of a behavioral theory of language and cognitionknown as relational frame theory (Barnes-Holmes,Barnes-Holmes, McHugh & Hayes, 2004; Hayes,Barnes-Holmes, & Roche, 2001). RFT is a basictheory that describes the powerful effects oflanguage on human psychology. Like manybasic scientific theories, RFT is not especiallyaccessible to nonexperts, and uses unfamiliarterms (e.g., arbitrarily applicable derived rela-tional responding) in the name of precision. Inorder to make these basic concepts more useful topracticing clinicians, a more accessible model wasdeveloped, known variously as the psychologicalflexibility theory or the hexaflex model, and aseparate body of research has examined this theory(Levin, Hildebrandt, Lillis, & Hayes, 2012).Psychological flexibility theory is composed ofwhat Hayes, Barnes-Holmes, andWilson (2012) callmiddle-level terms, which are defined as looserfunctional abstractions that serve to orient prac-titioners to some features of a domain in functionalcontextual terms so as to produce better outcomesand to facilitate knowledge development (p. 7).Intervention techniques and strategies, althoughultimately rooted in FC and RFT, can be conceptu-alized from the perspective of this more accessiblemid-level model.Proponents of ACT, more than any other

contemporary psychotherapy approach, havestressed the interconnected nature of philosophy,basic theory, applied clinical theory, and technique,and have clearly articulated a vision of each of theselevels of analysis. This unified approach is knownas contextual behavioral science (CBS; Hayes,Barnes-Holmes, & Wilson, 2012; Hayes, Levin,Plumb, Villatte, & Pistorello, 2013; Ruiz, 2010).Whether considering CT, ACT, or any other

variant of the CBT family, an appreciation of thiscontinuum of levels of analysis from philosophy totheory to technique brings into focus severalconsiderations. First, the precision gained by morebasic theoretical levels of analysis sacrifices accessi-bility, and vice versa. Even if a thorough under-standing of basic theories underlying the majormodels of CBT were deemed desirable, questionsimmediately arise regarding how realistic it would beto train front-line clinicians in such theories. Second,although linked, concepts at one level of analysis donot directly dictate those at another. One can adoptthe philosophical and theoretical perspectives asso-ciated with ACT, for example, as a platform fromwhich to understand the techniques of CT. Likewise,one can use the philosophy and theory associatedwith CT to understand the clinical application ofACT. Third, a point that is often unappreciated isthat one cannot avoid theory and philosophy. Allpsychological applications are inevitably groundedin some theory, which is in turn rooted in basicphilosophical assumptions. However, these theoret-ical and philosophical assumptions often remainimplicit and unarticulated. When a cognitive thera-pist guides her anxious patient to test irrationalthoughts against data in order to correct systematicbiases on the assumption that doing so will reduceanxiety and lead to improved functioning, she ismaking a host of theoretical assumptions, whether ornot she realizes she is doing so.A corollary is that truetheoretical eclecticism is impossible. One can borrowconcepts fromdifferent theories and combine them innewways, but one has then created yet a new theory,not an eclecticmix of the original ones. Similarly, onecan utilize one theory in some circumstances andanother at other times, but doing so requires a meta-theory that guides, even if implicitly, the circum-stances under which each theory is to be applied;again, this is not true eclecticism. Thus, althoughclinicians can choose not to examine the (implicit)theories that underlie their work, they cannot trulyavoid theory altogether.This analysis raises the question of what level of

theory is necessary or desirable for clinicians toappreciate, as well as what specific theory or theoriesshould be prioritized. Calls for clinicians to havestronger theoretical grounding have generally failedto specify the kind of theory in question. In terms ofanalytic levels, should clinicians routinely appreciatethe philosophical assumptions that underlie themajor forms of CBT? Should they become fluent inbasic theories such as RFT? What about more

584 herbert et al .specific theories such as particular cognitive modelsor psychological flexibility theory? And once thelevel of analysis is clarified, which specific theoreticalapproaches should be emphasized? There is noreason to assume that all theories work equallywell as guides to effective clinical practice. These areultimately empirical questions. Testing them willrequire recognition of the different possiblemeaningsof theory, and clear specification of the kind oftheoretical knowledge under consideration.The question of the proper role of theory in

clinical practice shares similarities with the debateregarding the relative effectiveness of standardizedinterventions versus those based on a highlyindividualized case conceptualization. There iscurrently strong support, particularly within theCBT community, for approaches that emphasize caseconceptualization (e.g., Kuyken, Padesky,&Dudley,2009; Needleman, 1999; Norcross & Lambert,2011; Persons, 2008). However, there are surpris-ingly fewdata to support this position. In fact, there isa paucity of research in this area, and what data doexist are not especially favorable. Anumber of studiesraise questions about the inter-assessor reliability ofcase conceptualizations (Caspar et al., 2000; Eells,2001; Persons & Bertagnolli, 1999). The few trialsthat have directly evaluated the relative utility ofindividualized treatment have generally not beensupportive. For example, two early studies random-ized patients to three conditions: a standardizedintervention, one based on an individualized caseconceptualization, and a third condition in which thetreatment was either yoked to another participantscase conceptualization (Schulte, Kuenzel, Pepping,& Schulte-Bahrenberg, 1992) or was explicitlymismatched to the assessment of the participantsspecific problems (Nelson et al., 1989). In both cases,there were no differences in outcomes between thetwo individualized conditions, and in fact someevidence of the superiority of the standard interven-tion. It should be noted, however, that the caseconceptualizations used in these studies were quitecrude relative to modern standards, and werecertainly not well grounded in theory, and eachstudy had other methodological limitations. Never-theless, these results underscore the importance ofempirical tests of the role of theory in practice. It isnot enough that the value of theoretically guidedpractice is plausible; the burden of proof is on thosewho propose that theoretical knowledge improvespractice to demonstrate that this is the case.

Why Theory Probably Matters: The Caseof ACT

Because of its relatively well-developed theoreticalbasis and the emphasis placed by its proponentson linking philosophy, theory, and technology(i.e., application), ACT represents a useful contextfor examining questions regarding the utility of aworking knowledge of theory to effective clinicalpractice. There are at least three ways in which onemight practice ACT: (a) with familiarity of charac-teristic techniques but minimal knowledge of under-lying theory; (b) with a working knowledge of bothtechnique and psychological flexibility theory; or(c) with knowledge of technique, psychologicalflexibility theory, as well as more basic behavioraltheoretical concepts, including RFT. Let us imaginethree ACT therapists, each with these varyinglevels of theoretical understanding, facing the samechallenging case. The first clinician appreciates a fewkey ACT principles, such as the importance ofembracing rather than fighting distressing thoughtsand feelings, as well as many characteristic tech-niques, including common metaphors and experien-tial exercises. She applies these techniques in astandard order, first highlighting the futility of effortsto control distressing experiences, then presentingpsychological acceptance as an alternative, beforemoving on to enhancing the ability to distance oneselffromones experience, then on to values clarification,and so on. This approach will likely work well formany patients. In fact, the success of ACT self-helpinterventions (e.g., Fledderus, Bohlmeijer, Pieterse,&Schreurs, 2012; Hesser et al., 2012; Muto, Hayes, &Jeffcoat, 2011) and clinical trials following structuredtreatment protocols (Arch, Eifert, et al., 2012;Forman et al., in press; Hernndez-Lpez, 2009;Westin et al., 2011; Wetherell et al., 2011) speak tothe power of such an approach.But imagine a patient with severe generalized

anxiety with panic attacks, comorbid depression,marital problems, and a history of heart disease andother problems, includingmultiple heart attacks. Thepatient initially resonates with the idea that efforts tocontrol his distress have not worked, but despite thefirst ACT therapists use of multiple standardinterventions, he is unable to let go of the strugglewith his disturbing thoughts and feelings. Moreover,he objects to exercises promoting psychologicalacceptance on the grounds that merely acceptinghis catastrophic thoughts and his anxiety (andespecially panic) sensations may lead him to ignorethe impending signs of another heart attack,precluding effective action. In fact, mindfulnessmeditation exercises prescribed as homework haveprecipitated panic attacks. He also finds the idea thathe should focus his efforts on changing his behaviorrather than his subjective distress to reflect thetherapists lack of appreciation of the depth of hisemotional pain. The first therapist continues toinvoke metaphors and to enact more experiential

585theory in cbtexercises, in hopes of breaking through what hasnow become an increasingly deadlocked clash inperspectives.The second ACT therapist, who has a strong

working knowledge of psychological flexibilitytheory, is not tied to any particular sequence ofinterventions, nor even to any particular techniques.After further assessment, the therapist tentativelyconcludes that the patient has become highlyattached to an identity as a helpless victim of hismedical and psychological problems. He implementsinterventions designed to undermine the literal truthof, and limitations associated with, this particularidentity, as well as personal narratives more gener-ally. He also recognizes the very high level of thepatients fusion with his distressing thoughts andfeelings, and so begins defusion exercises slowly, inlimited contexts, before gradually expanding them toinclude longer time periods, more settings, and morepsychological contexts. The therapist recognizes thatthe patient has become so focused on his distress thathe has lost touch with any larger purposes in his life.The therapist judiciously introduces values clarifica-tion and goal-setting exercises, but is careful to avoiddoing so in a way that would come across asdismissive of the patients distress. A functionalanalysis reveals that the depression and maritalproblems appear to be secondary to the isolationresulting from the patients extreme anxiety, therebyjustifying focusing primarily on the latter, in antici-pation that the depression will lift and marital issuesresolve as the anxiety improves. The patient beginsmakingmore progress. However, the issue of his fearof another heart attack continues to loom large, andhe continues to resist fully embracing the notion ofpsychological acceptance for fear of dismissing signsof an impending heart attack. This, in turn, keepshim from pursuing various goal-directed activitiesand limits his overall quality of life.In addition to familiarity with standard ACT

techniques and psychological flexibility theory, thethird ACT therapist also has a thorough groundingin basic behavioral theories, including RFT. Sheunderstands that the patients unique history hasresulted in the word heart attack, feelings ofshortness of breath, and anxiety symptoms such astremulousness, sweaty palms, and racing thoughts,all sharing functional properties. As a result of thisstimulus equivalence, common physiologicalarousal has automatically come to elicit the sameemotional reaction that would occur from an actualheart attack. This has resulted not only in thepatients attempts to suppress any signs of arousal,but also in hypervigilance for the appearance of anysigns of arousal. Attempts to monitor and controlhis symptoms (known as experiential avoidancein ACT parlance) paradoxicallybut predictablyresult in greater anxiety. The therapist understandsthat learning is always additive, and that she cannoterase the relationship between anxiety symptomsand heart attack. But she can intervene to expandthe associations with the anxiety symptoms so thatthey also evoke additional, less ominous, responses,while she also works to weaken the control of all ofthe patients subjective experience over his behav-ior. This conceptualization leads her to introducethe idea that reality testing distressing thoughts,in this case thoughts about having a heart attack, isin fact useful in a limited sense, provided the issue athand is truly a question of information. She helpsthe patient carefully frame his questions, examinewhich of these are truly about needed information,and which function maladaptively to avoid anxietythrough unnecessary reassurance seeking. For theformer only, the therapist works with the patient toobtain relevant data (e.g., by checking with hiscardiologist about the differences between symptomsof anxiety and those of a heart attack). Once this isaccomplished, the stage is then set for experientialacceptance interventions, includingwhen theoreti-cally indicatedacceptance of the patients thoughtsthat he is having a heart attack. There is noassumption that the information will eliminate thedistressing thoughts or feelings. But one can nowmove beyond ongoing reality testing to beginexperiencing them from amore detached perspective,eventually even welcoming them openly and non-defensively, thereby minimizing their negative effects.Of course, it is possible that the first ACT therapist

with minimal theoretical grounding, or perhaps evena good clinician working from a different CBTframework, might make similar therapeutic movesbased on intuition and personal experience. Ourthesis, however, is that a well-developed theoryprovides a more reliable guide for conceptualizingand intervening with complex cases. This is not tosuggest that theory completely replaces judiciousclinical judgment. Applying theoretical concepts toindividual cases requires considerable clinical acu-men. The question is not whether clinical judgmentand skill are important, but whether practice that istheoretically guided will be more effective thanpractice that is not.

Call for ResearchAs noted above, the larger CBT community hasrecently increased attempts to link clinical interven-tions to basic theories of behavior change and morespecific models of psychopathology. This includesrenewed interest in the study of these theories in theirown right. RFT, for example, has recently witnessedstrong growth as evidenced in the number of

586 herbert et al .manuscripts published. For example, one analysisobserved an exponential growth in publicationspublished on RFT from 1991 to 2008, totaling 62empirical and 112 nonempirical manuscripts(Dymond et al., 2010). This body of research hassought to empirically and theoretically define RFTconcepts and to test predictions derived fromthe theory (e.g., the effects of multiple-exemplartraining). There is little question that such theoreticaldevelopment is critical to better understanding theorigins of psychopathology and other forms ofhuman suffering, and to the continued developmentof more effective assessment, prevention, and inter-vention technologies. The only alternative is apiecemeal collection of observations and surrepti-tious discoveries, which then must be individuallyevaluated for their utility in various contexts.So whereas theory may be indispensible for

psychotherapy innovators and researchers, ques-tions remain regarding the importance of theory topracticing clinicians. Addressing these questionswill require a multipronged research program.

therapist surveys

One lesson learned from earlier efforts was thatattempting to disseminate CBTs to practicing clini-cians will not work as a completely top-downprocess (Addis, Wade, & Hatgis, 1999). Manyclinicians have been unwilling, for various reasons,to alter their practices based on emerging researchfindings supporting specific approaches (Baker,McFall, & Shoham, 2008; Timbie, Fox, VanBusum, & Schneider, 2012). For example, Freiheit,Vye, Swan, and Cady (2004) surveyed practicingpsychologists and found that the majority were notusing exposure when treating anxiety disorders,despite the widespread consensus that exposure iscrucial to effective treatment. We would expect asimilar response if research emerged that supportedtheoretical knowledge in guiding treatment. Re-search on training clinicians in evidence-basedpractices suggests that a good values-interventionfit is essential for the adoption of new practices(Aarons, Sommerfeld, Hecht, Silovsky, & Chaffin,2009). Thus, clinicians who already may be com-fortable using CBT techniques but who still oper-ate using largely opposing theoretical models(e.g., psychodynamic) may not find replacing theirtheory readily acceptable. Similarly, those whosetheoretical knowledge is implicit, and who believethemselves to function atheoretically, may notreadily appreciate the value of acquiring theoreticalknowledge. Research suggests that clinicians tendto rely largely on their personal experiences andintuition when making clinical decisions (Gaudiano,Brown, & Miller, 2011; Stewart & Chambless,2007). Thus, it may be important to ensure thattherapists not only understand theory in the abstract,but also can develop personal experiences thatdemonstrate to them the utility of using theory toinform their practice. In addition, there are a numberof emotional barriers to learning new practices,including the increased effort required and thetemporary discomfort involved when trying anunfamiliar approach (Varra,Hayes,Roget,&Fisher,2008).Thus, it will be important to begin with national

surveys of therapists and students to answer anumber of related questions:

1. How do therapists currently view the role oftheory in informing their practices? Therapiststend to operate using tacit and idiosyncratictheories to guide their decisions, but theiropenness to learning and using specific theoriesrelated to CBTs specifically is unknown.

2. How familiar are therapists already in varioustheories underlying CBTs? Is it possible, forexample, that some therapists may be knowl-edgeable about certain theories, but may notregularly use them to inform their practice?Similarly, the depth of understanding canvary in ways that dramatically influence onespractices. To what extent do therapists adoptsimplified versions of therapies (help patientsto think more positively; help patients get intouch with/vocalize their emotions), andhow does this play out in practice?

3. How can practicing clinicians best be taughtto apply CBT theories to specific cases toimprove their evidence-based practice? Forexample, vignettes could be used to examinetherapists' ability to apply theory to treatinghypothetical clinical cases in an effort toidentify which areas require further training.

4. What are other practical barriers to learningCBT theories, and how can those beaddressed? For example, timing and cost oftraining are important barriers often cited byclinicians that impede their ability to learnnew practices.

The latter point underscores the importance ofmaking theories as accessible as possible, if they aregoing to be useful to clinicians. For example, theoriginal presentations of RFT (e.g., Hayes et al.,2001) emphasized theoretical precision and, as aresult, were difficult for nonexperts to follow.Recent strides have been made to make the theorymore accessible (e.g., Trneke, 2010), but even theseremain inappropriate for widespread dissemination

587theory in cbtamong practicing clinicians. Clearly, a great dealmore work is needed in this area.

evaluation of theories themselves

Theoretically guided practice assumes the validityof the theory itself (where validity in this contextrefers both to a theorys internal consistency andcoherence as well as its scientific support). Researchis needed to evaluate the theories underlyingpsychotherapies, and to guide their ongoing devel-opment. This research can include studies ofhypotheses derived from specific theories, as wellas studies of competing hypotheses derived fromdifferent theories. As discussed above, in the caseof CBS there is a rapidly developing literatureevaluating hypotheses derived from RFT. Levinet al. (2012) conducted a meta-analysis of 66laboratory-based component studies of the ACTspsychological flexibility model and found greatereffects for values, acceptance, present moment,mindfulness, and values components relative tocomparison conditions.In addition to empirical studies, conceptual

analyses are also needed to evaluate various aspectsof theories, including their internal consistency,explanatory power, parsimony, and degree ofconnection with actual intervention techniques. Forinstance, Hofmann and Asmundson (2008) usedGrosss (2001) theory of emotion regulation in anattempt to explain the differences between charac-teristic CT and ACT interventions. They suggestedthat cognitive restructuring (characteristic of CT)and psychological acceptance (characteristic ofACT)could be considered as antecedent-focused versusresponse-focused emotion regulation strategies, re-spectively. However, as we have noted elsewhere(Gaudiano, 2011; Herbert & Forman, 2013), thisanalysis fails on both conceptual and empiricalgrounds. Most centrally, the antecedent-response dis-tinction does not map well onto the restructuring-acceptance distinction. Cognitive restructuring oftentakes place after the emotional response has beenactivated, and in this sense would be a form ofresponse-focused emotion regulation. The ACTstrategies aimed at developing nonjudgmentalacceptance of distressing experience may lead overtime to a change in the way events themselves areexperienced and to decreased emotional arousal,so in that sense would be considered an antecedent-focused process. Thus, both CT and ACT interven-tions operate both before and following emotionalactivation. This example illustrates the importantrole of critical analyses of theoretical concepts, in thiscase with regard to the theory-technology link. Suchanalyses can help clarify the best targets for fruitfulempirical research.experimental trials

Ultimately, the best way to resolve questionsregarding the role of theory in clinical practice isthrough controlled research. Practicing clinicianscould be randomized to one group in which trainingand supervision is limited to technical and practicalaspects of the treatment versus a comparisoncondition in which a substantial portion of thetraining is devoted to building theoretical knowl-edge. Patient outcomes would then be assessed andcompared across therapist groups. An aim of thistype of studywould be to determinewhether trainingtime is more productively spent on technique oron theory. Variations on this basic design could beenvisioned, including comparisons of training indifferent theories, parametric studies of varyingamounts of theoretical training, and comparisonsof different training modalities, among others.Moreover, cost-benefit analyses could be includedin all of these studies.Of course, in order to draw firmconclusions it will be important to attend tomethodological details, such as pre- and posttrainingtests of clinicians theoretical knowledge, highlyknowledgeable and competent trainers, etc., in thedesign and execution of such studies.An early prototype of this kind of research was

conducted by Strosahl, Hayes, Bergan, and Romano(1998). In that study, practicing masters-levelclinicians working in a community health mainte-nance organization were assigned to receive trainingin ACT theory and technique (n = 8) or no addi-tional training (n = 10). At follow-up assessment,patients of the therapists who underwent traininghad significantly better outcomes on a number ofmeasures relative to patients of therapists who didnot receive the training. This study suffers from anumber ofmethodological weaknesses, including thelack of random assignment of therapists to condi-tions and the absence of control conditions to ruleout that receiving training in any CBT model wouldhave resulted in better outcomes. Nevertheless, itrepresents an early version of the kind of study thatcan examine the practical impact of training in theoryon clinical outcomes.

examination ofmediators/moderators

Researchers and clinicians are increasingly aware ofthe limitations in knowledge gained from so-calledhorse race trials in which two therapies are testedagainst each other and differences in outcomesalone are examined. First, many such trials havefailed to show clear differences in outcomes amongcompeting psychotherapies. Second, even whendifferences are found, these trials fail to provideclear evidence for which aspects of the treatments

practicing psychologists' attitudes toward psychotherapy

588 herbert et al .are responsible for those differences. It was over50 years ago that Gordon Paul (1967) famouslyasked, What treatment, by whom, is most effectivefor this individual with that specific problem, andunder which set of circumstances? (p. 111). Inmodern parlance, Paul is referring to questionsrelated to moderation and mediation of treatmenteffects. Moderation refers to who is more likely torespond to treatment or under what conditions atreatment is likely to be effective. Mediation refersto how a treatment works or the mechanismsthrough which a treatment produces its response.Historically, it has been difficult to examinesystematically these types of empirical questions.Although procedures for exploring questions ofmoderation and mediation in psychotherapy trialswere pioneered by Baron and Kenny (1986), manyimprovements have been made over recent years. Theease of use andpower of these techniques, especially insmaller psychotherapy samples, have grown dramat-ically (Kraemer, Kiernan, Essex, & Kupfer, 2008;Kraemer et al., 2002; Preacher & Hayes, 2008).A recent study of ACT versus traditional CBT for

mixed anxiety disorders provides an example of theknowledge that canbe gained froman examination ofmediators andmoderators. Althoughboth treatmentsimproved symptoms similarly (Arch, Eifert, et al.,2012), ACT produced somewhat greater improve-ments in cognitive defusion, which mediated out-comes in both treatments (Arch, Wolitzky-Taylor,et al., 2012). Furthermore, in terms of moderation,CBT produced better outcomes in those with greaterbaseline anxiety sensitivity, whereas ACT producedgreater improvements in those with comorbiddepression (Wolitzky-Taylor, Arch, Rosenfield, &Craske, 2012). Results such as these serve as testsof the theories underlying psychotherapy programs,and can lead to further developments of thosetheories.

ConclusionScholars of psychotherapy, and of CBTs in particu-lar, have repeatedly called over the past three decadesfor renewed interest in theory, and there are signsthat the field is beginning to heed such calls. Thisrenewed appreciation of the role of theory is drivenby the confluence of a number of factors, includingthe growth of third-generation models of CBT thattend to emphasize linking technique to theory, andthe development of refined statistical methods tostudy psychotherapy processes. Although the idealrole of theoretical knowledge in clinical practice isultimately an empirical question, there are goodreasons to hypothesize that a working knowledge oftheory may lead to enhanced outcomes. Evaluatingthese questions will require a multifaceted researchtreatment manuals. Journal of Consulting and ClinicalPsychology, 68, 331339.

Addis, M. E., Wade, W. A., & Hatgis, C. (1999). Barriers todissemination of evidence-based practices: Addressingpractitioners' concerns about manual-based psychother-apies. Clinical Psychology: Science and Practice, 6,430441.

Arch, J. J., Eifert, G. H., Davies, C., Vilardaga, J. C., Plumb,Rose, R. D., & Craske, M. G. (2012). Randomized clinicaltrial of cognitive behavioral therapy (CBT) versus accep-tance and commitment therapy (ACT) for mixed anxietydisorders. Journal of Consulting and Clinical Psychology,80, 750765.

Arch, J. J.,Wolitzky-Taylor, K. B., Eifert, G. H.,&Craske,M.G.(2012). Longitudinal treatment mediation of traditionalcognitive behavioral therapy and acceptance and commitmenttherapy for anxiety disorders. Behaviour Research andTherapy, 50, 469478.

Baker, T. B., McFall, R. M., & Shoham, V. (2008). Currentstatus and future prospects of clinical psychology: Toward ascientifically principled approach to mental and behavioralhealth care. Psychological Science in the Public Interest,9(2), 67103.

Barnes-Holmes, D. (2000). Behavioral pragmatism: No placefor reality and truth. The Behavior Analyst, 23, 191202.program, which will in turn depend on firstaddressing a number of conceptual issues regardingthe nature of theories to be examined.The importance of examining the role of theory in

clinical practice is underscored by recent initiatives todisseminate CBTs widely to front-line practitioners.Beginning in 2006 the U.K. governments have beenimplementing the Improving Access to PsychologicalTherapies program (Department of Health, 2011),which has committed hundreds of millions of dollarsto training thousands of therapists to provideCBT to over 600,000 people with disorders such asdepression and anxiety. In the U.S., the VA isimplementing a similar initiative to train cliniciansin CBT to improve access to effective treatmentamong military veterans (Ruzek, Karlin, & Zeiss, inpress). Taking full advantage of these efforts willrequire not only further theoretical developments,but also a better understanding of the role of theory inclinical practice.

References

Aarons, G. A., Sommerfeld, D. H., Hecht, D. B., Silovsky, J. F.,& Chaffin, M. J. (2009). The impact of evidence-basedpractice implementation and fidelity monitoring on staffturnover: evidence for a protective effect. Journal ofConsulting and Clinical Psychology, 77, 270280.

Ablon, J. S., Levy, R. A., & Katzenstein, T. (2006). Beyond brandnames of psychotherapy: Identifying empirically supportedchange processes. Psychotherapy, 43, 216231.

Addis, M. E. (2006). Methods for disseminating researchproducts and increasing evidence-based practice: Promises,obstacles, and future directions. Clinical Psychology:Science and Practice, 9, 367378.

Addis, M. E., & Krasnow, A. D. (2000). A national survey of

589theory in cbtBarnes-Holmes, Y., Barnes-Holmes, D., McHugh, L., & Hayes,S. C. (2004). Relational frame theory: Some implications forunderstanding and treating human psychopathology. Inter-national Journal of Psychology and Psychological Theory,4(2), 161181.

Baron, R. M., & Kenny, D. A. (1986). The moderator-mediatorvariable distinction in social psychological research:Conceptual, strategic, and statistical considerations. Journalof Personality and Social Psychology, 51, 11731182.

Beck, A. T. (1979). Cognitive therapy and the emotionaldisorders. New York, NY: Meridian/Penguin.

Beck, A. T. (2005). The current state of cognitive therapy: A40-year retrospective. Archives of General Psychiatry, 62,953959.

Beck, A. T. (2012, September). Comparing CBT with thirdwave therapies. Cognitive Therapy Today 17, 12, 6.

Borkovec, T. D., & Sibrava, N. J. (2005). Problems with the useof placebo conditions in psychotherapy research, suggestedalternatives, and some strategies for the pursuit of theplacebo phenomenon. Journal of Clinical Psychology, 61,805818.

Caspar, F., Pessier, J., Stuart, J., Safran, J. D., Samstag, L.W., &Guirguis, M. (2000). One step further in assessing howinterpretations influence the process of psychotherapy.Psychotherapy Research, 10, 309320.

David, D., & Montgomery, G. H. (2011). The scientific statusof psychotherapies: A new evaluative framework forevidence basedpsychosocial interventions.Clinical Psychology:Science and Practice, 18, 8998.

Department of Health. (2011). Talking therapies: A four-yearplan of action. London: Author.

Dozois, D. J. A., & Beck, A. T. (2011). Cognitive therapy. In J. D.Herbert, & E.M. Forman (Eds.),Acceptance andmindfulnessin cognitive behavior therapy: Understanding and applyingthe new therapies (pp. 2656). Hoboken, NJ: Wiley.

Dymond, S., May, R. J., Munnelly, A., & Hoon, A. E. (2010).Evaluating the evidence base for relational frame theory: Acitation analysis. The Behavior Analyst, 33(1), 97117.

Eells, T. D. (2001). Update on psychotherapy case formulationresearch. Journal of Psychotherapy Practice and Research,10, 277281.

Elkin, I., Gibbons, R. D., Shea, M. T., Sotsky, S. M., Watkins,J. T., Pilkonis, P. A., et al. (1995). Initial severity anddifferential treatment outcome in the National Institute ofMental Health Treatment of Depression CollaborativeResearch Program. Journal of Consulting and ClinicalPsychology, 63, 841847.

Fledderus, M., Bohlmeijer, E. T., Pieterse, M. E., & Schreurs,K. M. G. (2012). Acceptance and commitment therapy asguided self-help for psychological distress and positivemental health: A randomized controlled trial. PsychologicalMedicine, 42, 485495. http://dx.doi.org/10.1017/S0033291711001206

Foa, E. B., & Emmelkamp, P. M. G. (Eds.). (1983). Failures inbehavior therapy. NewYork, NY: Wiley.

Forman, E.M., Butryn,M., Juarascio,A. S., Bradley, L., Lowe,M.,Herbert, J. D., & Shaw, J. (in press). The Mind Your HealthProject: Evaluating an innovative behavioral treatment forobesity.Obesity.

Forman, E. M., & Herbert, J. D. (2009). New directions incognitive behavior therapy: Acceptance-based therapies.In W. ODonohue, & J. E. Fisher (Eds.), General principlesand empirically supported techniques of cognitive behaviortherapy (pp. 102114). Hoboken, NJ: Wiley.

Freiheit, S. R., Vye, C., Swan, R., & Cady, M. (2004).Cognitive-behavioral therapy for anxiety: Is disseminationworking? the Behavior Therapist, 27, 2532.Gaudiano, B. A. (2011). A review of acceptance andcommitment therapy (ACT) and recommendations forcontinued scientific advancement. The Scientific Review ofMental Health Practice, 8, 522.

Gaudiano, B. A., Brown, L. A., & Miller, I. W. (2011). Let yourintuition be your guide? Individual differences in the evidence-based practice attitudes of psychotherapists. Journal ofEvaluation in Clinical Practice, 17, 628634.

Goldfried, M. R., & Davison, G. C. (1994). Clinical behaviortherapy. Oxford, England: John Wiley & Sons.

Gross, J. J. (2001). Emotion regulation in adulthood: Timing iseverything. Current Directions in Psychological Science, 10,214219.

Hayes, S. C. (1993). Analytic goals and varieties of scientificcontextualism. In S. C. Hayes, L. J. Hayes, H. W. Reese, &T. R. Sarbin (Eds.), Varieties of scientific contextualism(pp. 1127). Reno, NV: Context Press.

Hayes, S. C. (2004). Acceptance and commitment therapy,relational frame theory, and the third wave behavioral andcognitive therapies. Behavior Therapy, 35, 639665.

Hayes, S. C., Barnes-Holmes, D., & Roche, B. (2001). Relationalframe theory: A post-Skinnerian account of human languageand cognition. New York, NY: Kluwer Academic/Plenum.

Hayes, S. C., Barnes-Holmes, D., & Wilson, K. G. (2012).Contextual behavioral science: Creating a science moreadequate to the challenge of the human condition. Journal ofContextual Behavioral Science, 1, 116.

Hayes, S. C., Levin, M. E., Plumb, J. C., Villatte, J. L., &Pistorello, J. (2013). Acceptance and commitment therapyand contextual behavioral science: Examining the progressof a distinctive model of behavioral and cognitive therapy.Behavior Therapy, 44(2), 180198.

Hayes, S. C., Strosahl, K. D.,&Wilson, K.G. (2011).Acceptanceand commitment therapy: The process and practice ofmindfulchange (2nd ed.). New York, NY: Guilford.

Herbert, J. D., & Forman, E. M. (2011). The evolution ofcognitive behavior therapy: The rise of psychologicalacceptance and mindfulness. In J. D. Herbert & E.M.Forman (Eds.), Acceptance and mindfulness in cognitivebehavior therapy: Understanding and applying the newtherapies (pp. 325). Hoboken, NJ: Wiley.

Herbert, J. D., & Forman, E. M. (2013). Caution: Thedifferences between CT and ACT may be larger (andsmaller) than they appear. Behavior Therapy, 44(2),218223.

Hernndez-Lpez, M., Luciano, M. C., Bricker, J. B.,Roales-Nieto, J. G., & Montesinos, F. (2009). Acceptanceand commitment therapy for smoking cessation: A prelim-inary study of its effectiveness in comparison with cognitivebehavioral therapy. Psychology of Addictive Behaviors, 23,723730. http://dx.doi.org/10.1037/a0017632

Hesser,H.,Gustafsson, T., Lunden,C.,Henrikson,O., Fattahi, K.,Johnsson, E., . . . Anderson, G. (2012). A randomizedcontrolled trial of internet-delivered cognitive behavior therapyand acceptance and commitment therapy in the treatment oftinnitus. Journal of Consulting and Clinical Psychology, 80,649661. http://dx.doi.org/10.1037/a0027021

Hofmann, S. G. (2008). Common misconceptions aboutcognitive mediation of treatment change: A commentary toLongmore and Worrell (2007). Clinical Psychology Review,28, 6770.

Hofmann, S. G., & Asmundson, G. J. (2008). Acceptance andmindfulness-based therapy: New wave or old hat? ClinicalPsychology Review, 28, 116.

Klepac, R. K., Ronan, G. F., Andrasik, F., Arnold, K., Belar, C.,Berry, S., . . . Strauman, T. J. (2012). Guidelines forcognitive behavioral training within doctoral psychology

590 herbert et al .programs in the United States of America: Report of theInter-Organizational Task Force on Cognitive and Behav-ioral Psychology Doctoral Education. Behavior Therapy,43(4), 687697.

Kraemer, H. C., Kiernan, M., Essex, M., & Kupfer, D. J. (2008).How and why criteria defining moderators and mediatorsdiffer between the Baron & Kenny and MacArthur ap-proaches. Health Psychology, 27, S101S108.

Kraemer, H. C., Wilson, G. T., Fairburn, C. G., & Agras, W. S.(2002). Mediators and moderators of treatment effects inrandomized clinical trials. American Journal of Psychiatry,59, 877883.

Kuyken, W., Padesky, C. A., & Dudley, R. (2009). Collabo-rative case conceptualization: Working effectively withclients in cognitive-behavioral therapy. New York, NY:Guilford.

Levin, M. E., Hildebrandt, M. J., Lillis, J., & Hayes, S. C.(2012). The impact of treatment components suggested bythe psychological flexibility model: A meta-analysis oflaboratory-based component studies. Behavior Therapy,43, 741756.

Lewin, K. (1951). Problems of research in social psychology.In D. Cartwright (Ed.), Field theory in social science:Selected theoretical papers (pp. 155169). New York,NY: Harper & Row.

Linehan, M. M. (1993). Cognitive-behavioral treatment ofborderline personality disorder. New York, NY: Guilford.

Lohr, J. M., DeMaio, C., & McGlynn, F. D. (2003). Specificand nonspecific treatment factors in the experimentalanalysis of behavior treatment efficacy. Behavior Modifica-tion, 27, 322368.

Longmore, R., & Worrell, M. (2007). Do we need to challengethoughts in Cognitive Behavioural Therapy? ClinicalPsychology Review, 27, 173187.

McKay, D., Abramowitz, J. S., & Taylor, S. (Eds.) (2010).Cognitive-behavioral therapy for refractory cases: Turningfailure into success.Washington,DC:American PsychologicalAssociation.

Muto, T., Hayes, S. C., & Jeffcoat, T. (2011). The effectivenessof acceptance and commitment therapy bibliotherapy forenhancing the psychological health of Japanese collegestudents living abroad. Behavior Therapy, 42, 323335.http://dx.doi.org/10.1016/j.beth.2010.08.009

Needleman, L. D. (1999). Cognitive case conceptualization: Aguidebook for practitioners. Mahwah, NJ: LawrenceErlbaum.

Nelson, R. O., Herbert, J. D., Herbert, D. L., Sigmon, S. T., &Brannon, S. E. (1989). The importance of assessment in thetreatment of depression. Journal of Behavior Therapy andExperimental Psychiatry, 20, 281294.

Norcross, J. C.,&Lambert,M. J. (2011). Evidence-based therapyrelationships. In J. C. Norcross (Ed.), Psychotherapy relation-ships that work: Evidenceased responsiveness (2nd ed.,pp. 3-21). New York, NY: Oxford University Press.

Oxford English Dictionary Online. (2012). Oxford, England:Oxford University Press. http://www.oed.com/view/Entry/200431?rskey=QDQq9v&result=1&isAdvanced=false(accessed February 18, 2013).

Paul, G. L. (1967). Strategy of outcome research in psycho-therapy. Journal of Consulting Psychology, 31, 109118.

Persons, J. B. (2008). The case formulation approach tocognitive-behavior therapy. New York, NY: Guilford.

Persons, J. B., & Bertagnolli, A. (1999). Inter-rater reliability ofcognitive-behavioral case formulations of depression: areplication. Cognitive Therapy and Research, 23, 271283.

Preacher, K. J., & Hayes, A. F. (2008). Asymptotic resamplingstrategies for assessing and comparing indirect effects inmultiple mediator models. Behaviour Research Methods,40, 879891.

Rosch, E. (1983). Prototype classification and logicalclassification: The two systems. In E. K. Scholnick (Ed.),New trends in conceptual representation: Challenges toPiagets theory? (pp. 7386). Hillsdale, NJ: LawrenceErlbaum.

Rosen, G. M., & Davison, G. C. (2003). Psychology should listempirically supported principles of change (ESPs) and notcredential trademarked therapies or other treatment pack-ages. Behavior Modification, 27, 300312.

Ross, A. O. (1985). To form a more perfect union: It is time tostop standing still. Behavior Therapy, 16, 195204.

Ruiz, F. J. (2010). A review of Acceptance and CommitmentTherapy (ACT) empirical evidence: Correlational, experi-mental, psychopathology, component and outcome studies.International Journal of Psychology and PsychologicalTherapy, 10(1), 125162.

Ruzek, J. I., Karlin, B. E., & Zeiss, A. M. (in press).Implementation of evidence-based psychological treatmentsin the Veterans Health Administration. In R.K. McHughand D. H. Barlow (Eds.), Dissemination of evidence-basedpsychological treatments. New York, NY: Oxford UniversityPress.

Schulte, D., Kuenzel, R., Pepping, G., & Schulte-Bahrenberg, T.(1992). Tailor-made versus standardized therapy of phobicpatients. Advances in Behaviour Research & Therapy, 14,6792.

Segal, Z. V., Williams, J. M. G., & Teasdale, J. D. (2002).Mindfulness-based cognitive therapy for depression: Anew approach to preventing relapse. New York, NY:Guilford.

Stewart, R. E., & Chambless, D. L. (2007). Does psychotherapyresearch inform treatment decisions in private practice?Journal of Clinical Psychology, 63, 267281.

Strosahl, K. D., Hayes, S. C., Bergan, J., & Romano, P.(1998). Assessing the field effectiveness of Acceptanceand Commitment Therapy: An example of the manipu-lated training research method. Behavior Therapy, 29,3564.

Timbie, J. W., Fox, D. S., Van Busum, K., & Schneider, E. C.(2012). Five reasons that many comparative effectivenessstudies fail to change patient care and clinical practice.Health Affairs, 31, 21682175.

Trneke, N. (2010). Learning RFT: An introduction torelational frame theory and its clinical application.Oakland,CA: New Harbinger.

Varra, A. A., Hayes, S. C., Roget, N., & Fisher, G. (2008). Arandomized control trial examining the effect of acceptanceand commitment training on clinician willingness to useevidence-based pharmacotherapy. Journal of Consultingand Clinical Psychology, 76, 449458.

Westin, V. Z., Schulin, M., Hesser, H., Karlsson, M., Noe, R. Z.,Olofsson, U., . . . Andersson, G. (2011). Acceptance andCommitment Therapy versus Tinnitus Retraining Therapy inthe treatment of tinnitus: A randomised controlled trial.Behaviour Research and Therapy, 49, 737747. http://dx.doi.org/10.1016/j.brat.2011.08.001

Wetherell, J. L., Afari, N., Rutledge, T., Sorrell, J. T., Stoddard,J. A., Petkus, A. J., . . . Atkinson, J. H. (2011). Arandomized, controlled trial of acceptance and commitmenttherapy and cognitive-behavioral therapy for chronic pain.Pain, 152, 20982107. http://dx.doi.org/10.1016/j.pain.2011.05.016

Whisman, M. (Ed.). (2008). Adapting cognitive therapyfor depression: Managing complexity and comorbidity.NewYork, NY: Guilford.

Wilson, G. T., & Franks, C. M. (Eds.). (1982). Contemporarybehavior therapy: Conceptual and empirical foundationsNew York, NY: Guilford.

Wolitzky-Taylor,K. B., Arch, J. J., Rosenfield,D.,&Craske,M.G.(2012). Moderators and non-specific predictors of treatmentoutcome for anxiety disorders: a comparison of cognitivebehavioral therapy to acceptance and commitment therapy.Journal of Consulting and Clinical Psychology, 80, 786799.

Worrell, M., & Longmore, R. J. (2008). Challenging Hofmann'snegative thoughts: A rebuttal. Clinical Psychology Review, 28,7174.

RECEIVED: November 12, 2012ACCEPTED: March 1, 2013Available online 13 March 2013

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