Effect of Prazosin on Neurophysiology and Cognition in Post-Traumatic Stress Disorder (PTSD)

Study Overview
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Brief Summary
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In this study, the investigators are looking at how PTSD affects things such as memory, attention, reaction to sounds, eye movements, and heart rate. The investigators are also studying whether a medication called prazosin has an effect on these things.

Detailed Description
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Converging lines of evidence suggest that central nor adrenergic function is perturbed in PTSD. Placebo-controlled trials demonstrate that the centrally acting alpha-1 antagonist prazosin is clinically effective for several core symptoms of PTSD in combat veterans. However, no detailed assessment of the impact of prazosin on human neurophysiology and cognition have been conducted. Our hypotheses are based on studies that demonstrate (1) the importance of central adrenergic receptors in regulating fundamental neurophysiologic and cognitive functions, (2) the alteration of these functions in PTSD, and (3) the efficacy of prazosin in improving the clinical symptoms of PTSD. The primary objective of this study is to measure the subtle neurocognitive and neurophysiologic effects on prazosin in combat veterans with PTSD.

Official Title
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Effect of Prazosin on Neurophysiologic Responses and Cognitive Performance in PTSD

Conditions
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Posttraumatic Stress Disorder

Intervention / Treatment
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* Drug: prazosin hydrochloride
* Drug: placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Exposure to one or more life-threatening war zone trauma events; DSM-IV diagnosis of PTSD derived from the Clinician-Administered PTSD Scale (CAPS), CAPS total score greater than or equal to 50; CAPS recurrent distressing dreams item score greater than or equal to 5 (of a maximum score of 8), with a frequency rating greater than or equal to 2 (of 4); stable dose of non-exclusionary medications and psychotherapeutic treatment for at least 4 weeks prior to randomization; good general medical health; female participants must agree to use a reliable form of birth control throughout study. Exclusion Criteria: Acute or unstable chronic medical illness; diagnosis of current schizophrenia, schizoaffective disorder, psychotic disorder not otherwise specified, bipolar disorder, delirium, or cognitive disorder; severe psychiatric instability or severe situational life crises; substance dependence disorder currently or in past 3 months; current cocaine or stimulant abuse or evidence of acute intoxication on alcohol or nonprescribed medication; allergy or previous adverse reaction to prazosin or other alpha-1 adrenergic antagonists; serious head injury with loss of consciousness of greater than 30 minutes; current diagnosis of seizure disorder; current use of prazosin or other alpha-1 adrenergic antagonists; current use of atypical antipsychotic medication; stimulants or alternative medications with stimulant properties (e.g. ephedra), certain exposure therapies must be completed at least 4 weeks before baseline; certain medications (trazodone, erectile disfunction medications) are not allowed or are restricted during the study; women must not be pregnant or nursing during the study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

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: Arm 1<br>Persons with PTSD | Drug: prazosin hydrochloride<br>* prazosin 1-20 mg/day in divided doses<br>* Other names: Minipress;|
| Placebo Comparator: Arm 2<br>Persons with PTSD | Drug: placebo<br>* placebo<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Responses to acoustic startle and prepulse inhibition of acoustic startle |  | baseline, week 2, week 8 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart rate variability |  | baseline, week 2, week 8 | 
| Pennsylvania Computerized Neurocognitive Battery (CNB) |  | baseline, week 8 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Stress disorders, post-traumatic, Combat Disorders, prazosin, cognition, neurophysiology