Genetic polymorphisms involved in fear conditioning

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 402

Inclusion Criteria

Subjects must meet the following inclusion criteria in order to participate in the study:
a. Male or female volunteers ages 18-40 years old for the initial sample of 150. For the additional control sample of 50 to be used as comparison for the patients with anxiety disorders measured under protocol ID: 35780.041.11, the inclusion criterion for age is between 30-65 years old.
b. Judged to be in good physical and psychiatric health on the basis of medical history.
c. Able to understand procedures and agree to participate in the study by giving written informed consent.
d. Normal or corrected to normal vision
e. Caucasian ethnicity;Comment: Caucasian ethnicity will be an inclusion criterion to be able to guarantee as exact as possible that distribution of the measured polymorphism will be identical to earlier studies done in Caucasians. This is important to estimate the power and necessary sample size as exact as possible.;Follow-up study (addendum 28-04-11):
Same in- and exclusion criteria as described above, with additional requirement that participants successfully participated in the study Genetic polymorphisms involved in fear conditioning in 2010-11 of which this study is a follow-up and gave permission to be contacted for potential follow-up experiments.;Replication study:
No additional includion criteria.

Exclusion Criteria

Subjects will be excluded from the study if they meet the following exclusion criteria:;a. Clinically significant abnormalities in medical history.
b. History of any disease, which in the investigators* opinion may confound the results of the study, including, but not limited to, history of organic mental disorders, seizure, or mental retardation.
c. Lifetime history of substance dependence, or substance abuse within past 1 year.
d. Current diagnosis of Axis I or Axis II psychiatric disorder.
e. Psychotropic medication within 4 weeks of testing.
f. Hearing problems
G. Participated in the original study (for the replication study)
Comment: All exclusion criteria will be assessed by an interview with associate investigator #1 by phone. Hearing problems are an exclusion criterion due to the fact that auditive stimuli are used during the experimental session.;Replication study:
One extra criterion will be added to the exclusion criteria, compared to the original protocol:
I. Participated in the original study

Study & Design

Study Type: Observational invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>Main study parameters/endpoints: Polymorphisms from four different<br /><br>neurotransmitter systems will be assessed to investigate the role of each<br /><br>neurotransmitter system in fear conditioning and fear/anxiety. Polymorphisms<br /><br>that will be genotyped include the following genes: the 5-HTLLPR serotonin<br /><br>transporter, the 5HTR1A serotonin 1A receptor, the SLC6A3 dopamine transporter<br /><br>and the COMT Val158Met. In addition, we will determine the participants* CB1<br /><br>receptor and CRHR1 polymorphisms. Participants will perform fear-conditioning<br /><br>and fear extinction tasks in which the fear potentiated startle response and<br /><br>skin conductance of each subject will be assessed. </p><br>

Secondary Outcome Measures

Name	Time	Method
<p>Furthermore, individual conditioning/extinction capabilities during the tasks<br /><br>will be measured in relation to cues and context. Data from the 50 volunteers<br /><br>in the additional group aged 30-65 will be applied as healthy control sample<br /><br>for the patients with anxiety disorders in protocol ID: 35780.041.11.</p><br>