Stress Reactivity in Veterans Receiving Pharmacological Treatment for PTSD and Alcohol Dependence

Specific Aim: We propose a laboratory study that will examine stress reactivity as a marker
for treatment response to prazosin in patients with PTSD and AD.

Background: Increasing evidence shows that PTSD and AD are both associated with
abnormalities in stress reactivity. In PTSD, the increase in hormonal response and
subjective increases in affective symptoms provide evidence for abnormalities in stress
reactivity. In AD, significant increases in craving after stressful stimuli and alcohol cues
point to abnormalities in stress response. There is increasing evidence that these
laboratory paradigms are clinically relevant and may be useful in predicting treatment
outcomes in patients with substance use disorders. Stress induced craving has been used as a
marker for relapse. Individuals with greater stress reactivity have a shorter time to
relapse to their preferred substance than individuals with lesser stress reactivity.

Attenuation of trauma-related distress may be effective in reducing both craving and
negative affect in individuals with PTSD and AD. In a very elegant study, Coffey and his
colleagues (Coffey et al, 2006) found that imaginal exposure therapy was more effective than
relaxation alone in reducing craving for alcohol after exposure to stressful imagery and
alcohol cues. However, it should be noted that interventions such as imaginal exposure
therapy target only symptoms of PTSD, have to be administered by highly trained
professionals and have to be provided in specialized settings.

We propose a laboratory study that will test whether pharmacotherapy that targets both
symptoms of PTSD and AD can attenuate the stress response, and how the attenuation of stress
response will affect relapse and outcome.

Method: This study is designed as an accompaniment to an already funded study by the DOD - a
12-week treatment trial with prazosin for patients with PTSD and AD. The current proposal
will augment the findings from the treatment study and identify for which patients prazosin
may be effective. It is important to note that this study is very different from the PTSD
Coop study in that study EXCLUDES individuals with alcohol dependence. The DOD study and
this companion study will provide answers relevant to alcohol use, alcohol relapse and
drinking outcomes.

The study design will consist of III phases. In phase I, all subjects will participate in
three laboratory sessions to determine their reactivity to stress. Stress reactivity will be
measured using: traumatic experiences, stressful non-trauma experiences and neutral
experiences, presented randomly. Laboratory sessions will be conducted in an inpatient
setting. Phase II is a randomized clinical trial evaluating prazosin versus placebo for 12
weeks in a double-blind, controlled fashion in an outpatient setting. The treatment will
last for 12 weeks and outcomes will include symptoms of PTSD and alcohol use. In phase III,
subjects will again be admitted to an inpatient unit. This phase of the study will be
conducted during the 12th and final week on medication while participants are still
receiving prazosin or placebo.

Hypotheses: Primary: We hypothesize that prazosin will be more effective than placebo in
reducing trauma-related stress reactivity in a laboratory paradigm, particularly anxiety,
craving for alcohol, and hormonal response, in individuals with PTSD and AD. And this will
be a marker for treatment response to prazosin in patient with PTSD and AD.

Secondary: We hypothesize that stress reactivity will have a moderating effect on treatment
with prazosin, such that individuals with high levels of stress reactivity will have fewer
heavy drinking days, a significant reduction in PTSD symptoms, and shorter time to relapse
than individuals with low levels of stress reactivity.

Inclusion Criteria:

- male and female patients age 21 to 65.

- current diagnosis of DSM-IV PTSD (determined by SCID and CAPS and AD (determine by
SCID)).

- participants who drink regularly (determined by TLFB and recorded 90 days prior to
the interview), and are not abstinent for more than 2 weeks before participation in
the study.

- are not in an active phase of alcohol withdrawal.

- are not at risk for suicide.

Exclusion Criteria:

- current SCID diagnosis of any psychotic disorder.

- history of substance dependence (other than alcohol and nicotine) in the last 30
days.

- current unstable medical condition such as neurological, cardiovascular, endocrine,
renal, liver, or thyroid pathology (LFT 5 times normal, abnormal BUN and creatinine,
and unmanaged hypertension with BP > 200/120) which in the opinion of the physician
would preclude the patient from fully cooperating or be of potential harm during the
course of the study.

- taking medication for a psychiatric condition.