Effects of Verbal Instructions on Fear Extinction and Extinction Retrieval

Study Overview
=================
Brief Summary
-----------------
The goal of this study is to examine if verbal instructions can improve fear extinction learning and extinction retrieval in patients with anxiety disorders (AD) and healthy controls.

Detailed Description
-----------------
Patients with anxiety disorders (AD) and highly anxious individuals show accelerated fear conditioning and diminished fear extinction learning (Duits et al., 2015). The aim of the current study is to investigate how verbal instructions impact fear extinction learning and extinction retrieval in AD patients and healthy controls. Using a 3-day fear conditioning paradigm, fear acquisition will take place on the first, extinction training on the second, and extinction retrieval and reinstatement on the third day (i.e., all phases are on consecutive days). Part of the participants will receive explicit instructions such that the unconditioned stimulus (UCS) won't be presented anymore, either before and/or after extinction training. Participants will be randomly assigned to four conditions: (1) no explicit instructions at all, (2) explicit instructions before extinction, (3) explicit instructions after extinction or (4) explicit instructions before and after extinction.

Official Title
-----------------
The Effects of Verbal Instructions on Fear Extinction and Extinction Retrieval in Patients With Anxiety Disorders and Healthy Controls

Conditions
-----------------
Anxiety Disorder

Intervention / Treatment
-----------------
* Other: Explicit instructions before extinction
* Other: Explicit instructions after extinction


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: For the patient group: DSM-5 anxiety disorder diagnosis via a structured clinical interview for diagnosing mental disorders (DIPS) For the healthy controls: no psychological disorder according to the Mini-DIPS Exclusion Criteria: smoking alcohol abuse drug consumption current and chronic physical and neurological diseases for the patient group: anxiety not the primary diagnosis, psychological comorbidities e.g. schizophrenia, bipolar disorder, mental retardation, acute drug or alcohol addiction, personality disorder, currently in psychotherapy for the healthy controls: a diagnosis of psychological disorder at any point in life, ever been in psychotherapy, current and/or regular intake of medicine (incl. psychopharmaceutic medicine), current or past cognitive or neurological disorder for women: pregnancy, nursing period previous experience with fear conditioning paradigm

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Explicit instructions before + after extinction<br> | Other: Explicit instructions before extinction<br>* Shocks will no longer be administered during the next phase.<br>Other: Explicit instructions after extinction<br>* Tomorrow no shocks will be administered.<br>|
| Experimental: Explicit instructions before extinction<br> | Other: Explicit instructions before extinction<br>* Shocks will no longer be administered during the next phase.<br>|
| Experimental: Explicit instructions after extinction<br> | Other: Explicit instructions after extinction<br>* Tomorrow no shocks will be administered.<br>|
| No Intervention: No explicit instructions<br> | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fear extinction learning | The difference between the reinforced conditioned stimulus (CS+) and non-reinforced conditioned stimulus (CS-) will be measured on 3 different levels: skin conductance responses (SCRs), CS valence ratings (How pleasant do you feel when you see this picture?), and UCS expectancy ratings (Do you think that this picture is paired with an electrical stimulation?). | Experimental Day 2 | 
| Extinction retrieval | The difference between the reinforced conditioned stimulus (CS+) and non-reinforced conditioned stimulus (CS-) will be measured on 3 different levels: skin conductance responses (SCRs), CS valence ratings (How pleasant do you feel when you see this picture?), and UCS expectancy ratings (Do you think that this picture is paired with an electrical stimulation?). | Experimental Day 3 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fear acquisition | The difference between the reinforced conditioned stimulus (CS+) and non-reinforced conditioned stimulus (CS-) will be measured on 3 different levels: skin conductance responses (SCRs), CS valence ratings (How pleasant do you feel when you see this picture?), and UCS expectancy ratings (Do you think that this picture is paired with an electrical stimulation?). | Experimental Day 1 | 
| Contingency awareness | After fear acquisition, it will be checked if participants can correctly determine which CS had been paired with the UCS. | Experimental Day 1 | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
anxiety disorders, fear extinction, fear conditioning, instructions, contingencies