Psychotherapy Effects on Reward Processing in PTSD — PERPP  

PTSD Clinical Trial

Official title: The Effects of Trauma-focused Psychotherapy on Reward Circuitry Function and Information Encoding

Status Not yet recruiting

Clinical Trial Summary

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.

Clinical Trial Description

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. Hypothesis: Under conditions of safety, treatment will enhance vmPFC ExpVal encoding, enhance VS encoding of PE, and decrease amygdala encoding of PE.

2. Identify how presence of threat augments PTSD psychotherapy effects on reward circuit function and information encoding. Hypothesis: In presence of threat vs. no threat, treatment will attenuate vmPFC ExpVal encoding, attenuate VS encoding of PE, and increase dorsolateral prefrontal cortex encoding of PE.

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. The investigators are choosing to focus on the syndromic diagnosis of PTSD in this study vs. DimPA in PTP more generally (which also frequently encompasses MDD as a diagnosis), because: a) trauma-focused psychotherapy has been validated on the syndromic diagnosis of PTSD; and b) providing this treatment to individuals without a PTSD diagnosis may diminish efficacy of the treatment in this sample, obscure detection of therapeutic mechanisms, and may not be clinically advantageous to the participant. Note that large sample-studies indicate that ~75% of individuals with a PTSD diagnosis have at least one symptom of DimPA (i.e. Emotional Numbing). Therefore, a diagnostic inclusion criterion is most likely to result in a maximally generalizable sample that will also be sensitive to CPT therapeutic effects. Individuals will undergo, prior to randomization, clinical and neurobiological assessment with 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). Finally, the investigators will incorporate a paradigm to assess emotion regulation in order to determine how this major aspect of CPT (cognitive reappraisal) relates to changes in reward circuitry function. 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. ;

Related Conditions & MeSH terms

• Anhedonia
• Chronic Post-Traumatic Stress Disorder
• Post Traumatic Stress Disorder
• PTSD
• Stress Disorders, Post-Traumatic
• Stress Disorders, Traumatic

• NCT number: NCT06096740
• Study type: Interventional
• Source: University of Texas at Austin
• Contact: Lauren Enten, B.S.A
• Phone: 512-495-5856
• Email: fonzolab@austin.utexas.edu
• Status: Not yet recruiting
• Phase: N/A
• Start date: June 1, 2024
• Completion date: May 1, 2029