Fear inhibition in PTSD patients; a fear-potentiated startle paradigm

Conditions: Anxiety disorder
post traumatic stress disorder

Registration Number: NL-OMON31162

Lead Sponsor: niversiteit van Amsterdam

Brief Summary: Not available

Detailed Description: Not available

Recruitment & Eligibility

Status: Pending

Sex: Not specified

Target Recruitment: 50

Inclusion Criteria

All subjects have experienced a work-related trauma. The main inclusion criteria for the experimental group is to meet the DSM IV criteria for PTSD as a consequence of a work related trauma.

Exclusion Criteria

The main exclusion criteria all subjects are; severe concentration problems, visual problems, hearing problems, pregancy, cardiovascular complaints and epilepsy. ;Exclusion criteria for the experimental group is severe comorbidity and PTSD as a consequence of complex trauma. Exclusion criteria of the control group are any DSM IV diagnosis.

Study & Design

Study Type: Observational invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>1. Startle respons is measured by exposure to the startle probe. Door<br /><br>middel van deze respons wordt de mate van angst en uiteindelijk de mate van<br /><br>inhibitie gemeten. De startle probe (akoestische stimulus) wordt binauraal<br /><br>door een koptelefoon geleverd. De startle probe bestaat uit een witte ruis<br /><br>(alle frequenties omvattende) geluidsstimulus met een geluidsdrukniveau van<br /><br>104-dbA en een duur van 40 msec.<br /><br><br /><br>2. Cognitive expectancy/contingency awareness: the online US expectancy is<br /><br>measured on a 11- point scale from certainly no electrical pulse to uncertain<br /><br>to *certain a elektric pulse'. After every stimulus presentation the online<br /><br>expectancy is registered.<br /><br><br /><br>3. Propositional knowledge: after the computertask is finished the<br /><br>questionnaire about the obtained knowledge about the stimuli are answered. </p><br>

Secondary Outcome Measures

Name	Time	Method
<p>Using the human fear conditioning paradigm it is demonstrated that the effects<br /><br>of extinction are largely confined to the context in which the extinction<br /><br>procedure took place (Vansteenwegen, Hermans, Vervliet et al., 2005).<br /><br>From the clinical viewpoint, it is suggested that changes in the constellation<br /><br>of the therapy context contribute to the sometimes reported Return of fear<br /><br>(Rachman, 1989) following successful therapy completion (see also Bouton, 2002)<br /><br>Bouton and colleagues (e.g. Bouton & Nelson)<br /><br>For these reasons, the effects of context on (transfer of) inhibition<br /><br>performance will be tested. It will be hypothesized that patients with PTSD<br /><br>will show less transfer of inhibition to another test context than controls. In<br /><br>other words, patients regard the safety cue in another context as less<br /><br>inhibitory.</p><br>