The purpose of this study is to identify how trauma-focused psychotherapy changes the function of brain circuitry in posttraumatic stress disorder (PTSD) and how this mediates improvements in the diminished ability to experience positive emotions following a traumatic or extremely stressful life event. In this instance, the investigators will be using cognitive processing therapy (CPT), a widely-utilized and evidence-based treatment for PTSD.
The goals of the study are as follows: 1. Quantify, under conditions of safety (no threat), how PTSD psychotherapy alters reward circuit function and information encoding. 2. Identify how presence of threat augments PTSD psychotherapy effects on reward circuit function and information encoding. 3. (Exploratory). Identify how, following psychotherapy, changes in reward circuit function and information encoding under conditions of safety and threat are associated with improvements in symptoms of diminished positive affect (DimPA). To accomplish the goals of the study, the investigators propose a neuroimaging-coupled, randomized clinical trial of immediate vs. delayed individual cognitive processing therapy (CPT) in individuals (N=120) with a primary diagnosis of chronic PTSD. Individuals will undergo, prior to randomization, clinical and neurobiological assessment with functional magnetic resonance imaging (fMRI) during completion of several reward processing paradigms. Two of these involve both a normal "safe" context and a threat context manipulation (threat of mild electrodermal shock that is periodically cycled throughout the task). Another paradigm involves making decisions to either approach reward or forego a reward when this decision conflicts with the likelihood of an aversive outcome. This is known as approach-avoidance conflict (AAC). This battery will provide a comprehensive characterization of reward processing behavior and circuit function and establish its relationship to treatment processes, as well as how such processes may vary as a function of threat.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
120
Cognitive processing therapy is a widely-utilized, empirically-supported treatment developed for PTSD. It is based on a cognitive theory of trauma which emphasizes the impact of trauma on belief systems and the development of "stuck points", which are unhealthy, unrealistic, and maladaptive ways of thinking that serve to maintain unhealthy beliefs and reinforce PTSD symptoms.
Health Discovery Building (HDB), 1601 Trinity St., Bldg B., Z0600
Austin, Texas, United States
RECRUITINGWithin subject beta coefficients for each parametrically modulated regressor of the Reinforcement Learning Task with Threat
The changes in deoxyhemoglobin driven by localized changes in brain blood flow and blood oxygenation associated with individual trial-by-trial reinforcement learning computational model parameters at the time of choice valuation (expected reward value during safe contexts and expected reward value during threat contexts) and choice outcome (reward prediction errors during safe contexts and reward prediction errors during threat contexts).
Time frame: [10 weeks]
Within-subject BOLD contrast for unexpected absence of juice vs. expected absence of juice (negative temporal Prediction Errors) for safe and threat contexts.
The changes in deoxyhemoglobin driven by localized changes in brain blood flow and blood oxygenation between the unexpected absence of juice vs. expected absence of juice in safe contexts and threat contexts.
Time frame: [10 weeks]
Within-subject BOLD contrast for the unexpected delivery of juice vs. the expected delivery of juice (positive temporal Prediction Errors) for safe and threat contexts.
The changes in deoxyhemoglobin driven by localized changes in brain blood flow and blood oxygenation between the unexpected delivery of juice vs. the expected delivery of juice in both safe and threat contexts.
Time frame: [10 weeks]
Within subject beta coefficients for each parametrically modulated regressor of an approach avoidance conflict task.
The changes in deoxyhemoglobin driven by localized changes in brain blood flow and blood oxygenation associated with individual trial-by-trial reinforcement learning computational model parameters at the time of choice valuation (expected reward value, expected threat value, and conflict between reward and threat value), anticipation (expected reward and threat value), and choice outcome (reward and threat prediction errors).
Time frame: [10 weeks]
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.