PTSD

Cognitive and Neurobiological Models of Post Traumatic Stress

Disorder

Mechanics of PTSD

What mechanisms are involved in PTSD symptoms?

Mechanisms

Neurobiological

Cognitive

Neurobiological

Neurochemical sensitization Use-dependent activation Neuro-cognitive development Cognitive organization in the developing

brain.

Perry, B. D., Pollard R. A., Blakley T. L., Baker, W. L., and Vigilante, D. (1995). Childhood trauma, the neurobiology of adaptation, and "use-dependent" development of the brain: how "states" become "traits". Infant Mental Health Journal, 16(4), 271-291.

Neurochemical Sensitization

“Once sensitized, the same neural activation can be elicited by decreasingly intense external stimuli.”“Sensitization may result when experience activates neurosensory apparatus, altering the pattern and quantity of neurotransmitter release throughout neuronal systems responsible for sensation, perception, and processing of that specific experience.” “[M]ay cause sensitization of neurotransmitter receptor/effectors to similar future neurotransmitter stimulation in all interconnected neural systems.”


In English…

The effects of a traumatic experience, on a neurological level, can influence future brain functioning.

The threshold of the limbic activation is lowered, such that a lower degree of stimulus is required to elicit a panic response• This would explain the exaggerated acoustic

startle response

Neurochemical Sensitization

Use-dependent Activation

Fear states become traits “(find quote) The more a pathway is activated,

the more primed it is for activation.” We were designed to respond appropriately to

our environment. If there is a frequency of occurrences in our environment, we will increase the use of the neuro-cognitive pathways that respond to the input.

Neuro-cognitive Development

“The brain develops in a sequential and hierarchal fashion.”• Limbic to cortical, brainstem to neocortex

“Disruption of experience-dependent neurochemical signals during these periods may lead to major abnormalities or deficits in neurodevelopment.”• Plasticity of the brain is higher in children;

therefore, children are more susceptible to “variance of experience”


Cognitive Development

“Experience literally provides the organizing framework for an infant and child…In early childhood, the child is most vulnerable to variance of experience during this time.”

Maintenance of PTSD symptoms can lead to diminished functioning across social, academic, and personal dimensions.


Cognitive Organization in the Developing Brain

•“Experiences, including traumatic,[…] will, during development, determine functional capacity of the human brain.”•States can become traits when all new experiences are interpreted through traumatic responses


Adaptive Responses to Threat

Child’s Response to Trauma

The child may either move along a hyperarousal continuum or a disscociative continuum.


Hyperarousal

Adaptive response Males tend to use hyperaroused responses. Linked to the “fight-or-flight” response from

the limbic system. During adolescence, when a child is

physiologically able to defend himself, hyperarousal responses are exhibited, while disscociative responses are diminished.

Can look like ADHD, CD, ODD


Child’s Response to Trauma

The child may either move along a hyperarousal continuum or a disscociative continuum.


Dissociation

Adaptive response Females tend to utilize dissociative

responses. Younger children tend to dissociate more

than older children. Tends to look like internalizing disorders:

depression, anxiety, or dissociative disorders.


Adaptive Style


Cognitive

Secondary emotionsThe traumatic memoriesThought control and suppressionRuminationNegative self-evaluationsAnxiety sensitivity

Meiser-Stedman, R. (2002). Towards a cognitive-behavioral model of PTSD in children and adolescents. Clinical Child and Family Psychology Review, 5(4), 217-230.

“Cognitive factors may play as significant a role in these aspects of the time course of PTSD as do pretraumatic and peri-traumatic experiences.”

Maintenance of PTSD Secondary emotions

• Feelings of guilt, anger may interfere with processing the traumatic memories The traumatic memories bring back the same physiological

effects experienced during the initial trauma. Thought control and suppression seems to increase the

frequency of disruptive and intrusive memories. Rumination

• Thinking about how the incident could have been prevented, changed, or avoided.

• Thoughts about justice or revenge when dealing with man-made trauma.• Females tend to use rumination as a coping strategy more than males.

Negative self-evaluations both “enhance a sense of current threat” and promote thought control strategies.

Anxiety sensitivity• Once a pathway is activated, the activation threshold is lowered across the

system.

Meiser-Stedman, R. (2002). Towards a cognitive-behavioral model of PTSD in children and adolescents. Clinical Child and Family Psychology Review, 5(4), 217-230.

Yerkes-Dodson Law

Accuracy of memory

• With high arousal, the accuracyand efficiency of memory decreases.

• During a traumatic experience,physiological arousal is very high.

“Onset of posttraumatic sympomatology may be strongly related to

the quality of the memory laid down during the traumatic event.”

Graph: Yerkes, R.M. & Dodson, J.D. (1908) The relation of strength of stimulus to rapidity of habit-formation. Journal of Comparative Neurology and Psychology, 18, 459-482

Quote: Meiser-Stedman, R. (2002). Towards a cognitive-behavioral model of ptsd in children and adolescents. Clinical Child and Family Psychology Review, 5(4), 217-230.

Clinical Applications

A better understanding of the underlying cognitive mechanisms can inform Cognitive-Behavioral Therapy (CBT) and make it much more effective by specifically focusing on the cognitive mechanisms involved in PTSD symptoms.

Development of other techniques that aid in cognitive restructuring, such as EMDR, can result.

Critical Analysis

Positive:• The studies in this field are consistent with

findings in cognitive psychology and neuropsychology

• High effecacy in application Negative:

• Most studies in this field are meta-analyses• Lack of controlled studies

Making Connections

• Victims of child abuse who do not meet full diagnostic criteria can display symptoms of PTSD• Investigation into a neuro-cognitive model can be used

to lessen disruptions in functioning • Prevention and relief of chronic symptoms of

anxiety can be facilitated with early intervention can be done with a better understanding of the underlying cognitive mechanisms• Many pathways are shared with PTSD

Developmental Context

• PTSD specific manifestations may change from childhood for adulthood

• CBT and cognitive restructuring will help patients avoid the cognitive state from becoming a trait

Ferry, N. C., Foa, Edna B., March, John, Treadwell, and Kimberli R. H. (2004). Posttraumatic stress disorder in youth: a critical review of the cognitive and behavioral treatment outcome literature. Professional Psychology: Research and Practice, 35(5), 466-476.

List of References• Meiser-Stedman, R. (2002). Towards a cognitive-behavioral model of ptsd

in children and adolescents. Clinical Child and Family Psychology Review, 5(4), 217-230. SECONDARY

• Perry, B. D., Pollard R. A., Blakley T. L., Baker, W. L., and Vigilante, D. (1995). Childhood trauma, the neurobiology of adaptation, and "use-dependent" development of the brain: how "states" become "traits". Infant Mental Health Journal, 16(4), 271-291. SECONDARY

• Yerkes, R.M. & Dodson, J.D. (1908) The relation of strength of stimulus to rapidity of habit-formation. Journal of Comparative Neurology and Psychology, 18, 459-482. PRIMARY

• Ferry, N. C., Foa, Edna B., March, John, Treadwell, and Kimberli R. H. (2004). Posttraumatic stress disorder in youth: a critical review of the cognitive and behavioral treatment outcome literature. Professional Psychology: Research and Practice, 35(5), 466-476. SECONDARY

PTSD

Health & Medicine

Transcript of PTSD