NCT04770584

Fear and Avoidance in PTSD Patients

Neural Correlates of Active Avoidance Learning and Their Interactions With Fear Extinction Mechanisms in PTSD Patients

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 300 (estimated)
• Sponsor: The University of Texas Health Science Center, Houston · Academic / Other
• Sex: All
• Age: 18 Years – 70 Years
• Healthy volunteers: Accepted

Summary

The purpose of this research study is to study how the brain learns to avoid certain stimuli or situations using an experimental paradigm. The big goal is to measure brain responses and subject's feelings and expectations when they are learning to actively avoid experimental stimuli, and how fear extinction learning and monetary cost can change how and when subjects are to avoid.

Detailed description

This study aims to study the neural correlates of avoidance learning using a recently validated conditioning and active avoidance paradigm (CAAP). The overarching objective is to measure the neural correlates of active avoidance, and how fear extinction learning and monetary cost modulate these avoidance responses. Participants will include healthy controls (HC), trauma-exposed healthy controls (TEHC), and participants with post-traumatic stress disorder (PTSD). Avoidance is common and often hinders the progression and success of extinction-based exposure therapy in PTSD. The data to be gathered in this study will enable us to probe neural mechanisms of avoidance, extinction, and decision-making to avoid or not, in addition to understanding the impact of cost on avoidance decision-making. These data will provide a more integrated platform for the understanding of the mechanisms of avoidance in both trauma-exposed healthy controls and PTSD psychopathology, which has important implications for treatment.

Conditions

• Post Traumatic Stress Disorder

Interventions

Type	Name	Description
BEHAVIORAL	Fear Conditioning	Participants will be administered increasing intensities of mild electric shock via electrodes connected to the foot. New Biopac stimulators that can deliver higher shock intensity, provided participants agreement will be used to assure adequate conditioning levels. Stimulation is measures in milliamps (mA), and each delivered stimulation will be 0.5 seconds long (500 milliseconds). To colored (blue, red, \& yellow) light stimuli (CS). The light stimulus is followed by a shock or no shock depending on color.
OTHER	Avoidance conditioning	Via button pressing. Only one stimulus-CS will enable control over experiencing the shock: the participant can press the button during the first 2 seconds of the light presentation to avoid the shock.
OTHER	Pavlovian fear extinction learning	After avoidance conditioning, the CS+ associated with avoidance responding appears with no button to press and no shock is administered.
OTHER	Willingness to pay to avoid shock	On the next day, participants receive a monetary stipend to use to pay to guarantee that they are not to receive any shocks if they press a button from the CS+. This and all previously described experimental phases noted above will occur inside of the fMRI scanner.

Timeline

• Start date: 2021-09-09
• Primary completion: 2027-01-01
• Completion: 2027-01-01
• First posted: 2021-02-25
• Last updated: 2025-04-11

Locations

1 site across 1 country: United States