Influence of the Noradrenergic System on the Formation of Intrusive Memories

Study Overview
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Brief Summary
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Intrusive memories of traumatic events are core features of posttraumatic stress disorder (PTSD) but little is known about the neurobiological formation of intrusions. The aim of this study was to determine whether the activity of the noradrenergic system during an intrusion-inducing stressor influences subsequent intrusive memories.

Detailed Description
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The investigators conducted an experimental, double-blind, placebo-controlled study in 118 healthy women. Prior to watching an established trauma film paradigm that induces short lasting intrusions, participants received a single dose of either 10 mg yohimbine, stimulating noradrenergic activity, or 0.15 mg clonidine, inhibiting noradrenergic activity, or placebo. The number of consecutive intrusions of the trauma film, the mean vividness of the intrusions and the mean degree of distress evoked by the intrusions were assessed during the following four days. Salivary cortisol and alpha-amylase were collected at seven time points prior to, and after the trauma film.

Official Title
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Influence of the Noradrenergic System on the Formation of Intrusive Memories: An Experimental Approach With a Trauma Film Paradigm

Conditions
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Intrusive Memories

Intervention / Treatment
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* Behavioral: Stress Film
* Drug: Yohimbine
* Drug: Clonidine
* Drug: placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy participants German on a native level Exclusion Criteria: former or present DSM IV Axis I disorders physical illnesses any medication intake (except oral contraceptive) history of sexual abuse or rape pregnancy or lactation period

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 44 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Yohimbine and Stress Film<br>Administration of 10mg yohimbine before the trauma film. | Behavioral: Stress Film<br> <br> Drug: Yohimbine<br> <br> |
| Experimental: Placebo and Stress Film<br>Administration of placebo before the trauma film. | Behavioral: Stress Film<br> <br> Drug: placebo<br> <br> |
| Experimental: Clonidine and Stress Film<br>Administration of 0.15mg clonidine before the trauma film. | Behavioral: Stress Film<br> <br> Drug: Clonidine<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of intrusive memories | Measured with an intrusion diary | four consecutive days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vividness of intrusive memories | Measured with an intrusion diary | four consecutive days | 
| Degree of distress of intrusive memories | Measured with an intrusion diary | four consecutive days |