The proposed study will examine the efficacy of doxazosin in the treatment of PTSD and alcohol use disorder or substance use disorders.
Due to sustained military conflicts in Afghanistan and Iraq over the past decade, there are an increasing number of U.S. military personnel and Veterans returning home with posttraumatic stress disorder (PTSD) and comorbid alcohol use disorders (AUD) and substance use disorders (SUD). If left untreated, Veterans with co-occurring PTSD and substance use disorders are at increased risk for developing other mental health problems (e.g., depression, anxiety), suicidal ideation and attempts, physical health problems, reduced resiliency and military readiness, employment problems, violence, and family/relationship impairment. While mental health services are in place for U.S. service members, substantial gaps in the treatment of co-occurring PTSD and SUD exist and there is little scientific evidence available to guide the provision of care. As part of the Consortium to Alleviate PTSD (CAP), the proposed study directly addresses this critical knowledge gap by testing the efficacy of doxazosin, a long-acting and selective alpha-1 adrenergic antagonist, as compared to placebo in reducing PTSD and AUD/SUD severity among U.S. military personnel. The medication to be investigated (doxazosin) represents a novel treatment approach for PTSD and AUD/SUD. While prazosin, also an alpha-1 adrenergic antagonist, has been shown to improve sleep and nightmares in military personnel with PTSD and may help reduce substance use severity, it has a short half-life of 2-3 hours and requires multiple doses each day, which is a significant limitation. In several pilot studies, doxazosin has shown promise in significantly reducing symptoms of PTSD and AUD/SUD and, in contrast to prazosin, it requires once per day dosing which confers a significant advantage in terms of translating positive findings into routine clinical practice. In this Stage II study, the investigators will (1) employ a two-arm randomized, double-blind, between-groups experimental design that will consist of 12 weeks of treatment with doxazosin or placebo medication; (2) use standardized, repeated dependent measures to rigorously assess PTSD symptomatology and AUD/SUD severity; (3) measure impairment in associated mental and behavioral health problems (e.g., depression, anxiety, sleep, risky behaviors, family/social functioning); and (4) use functional magnetic resonance imaging (fMRI) to investigate the underlying pathophysiology of comorbid PTSD/AUD and identify prognostic indicators of treatment outcome. To achieve these aims, the investigators have assembled a multidisciplinary team of investigators with nationally-recognized expertise in combat-related PTSD, substance use disorders and neuroimaging who have successfully collaborated in the past and are uniquely qualified to implement this type of investigation. The investigators represent a collaboration of faculty at the Ralph H. Johnson Veterans Affairs (VA) Medical Center and the Medical University of South Carolina (MUSC) in Charleston, SC.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
144
Ralph H. Johnson VA Medical Center, Charleston, SC
Charleston, South Carolina, United States
Clinician Administered PTSD Scale
The primary PTSD outcome measure was the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5; Weathers et al., 2013). The CAPS-5 is a semi-structured interview that measures the DSM-5 symptoms of PTSD and requires the presence of at least one intrusion symptom, one avoidance symptom, two cognition and mood symptoms, and two arousal symptoms for a period of 1 month or more to reach diagnostic threshold. There are 20 symptom items and responses that are rated on a 5-point scale ranging from 0 (absent) to 4 (extreme/incapacitating), with a total PTSD symptom severity score of the sum of the 20 symptom items ranging from 0-80, and lower scores indicating better outcomes (or less severe PTSD symptomology). The CAPS-5 was assessed at end of treatment (week 12).
Time frame: 12 Weeks
PTSD Checklist (PCL-5)
The secondary PTSD outcome measure was the PTSD Checklist-5 (PCL-5; Weathers et al., 2013b). The PCL-5 is 20-item self-report measure that assesses the DSM-5 symptoms of PTSD using a severity rating Likert scale ranging from 0 to 4 that indicates the degree of distress across symptoms (0 = not at all to 4 = extremely). The overall score range is 0-80 (and combines the score for all 20 symptoms), with lower scores representing better outcomes (less severe PTSD symptomology). The PCL-5 was assessed at end of treatment (week 12).
Time frame: 12 Weeks
Time Line Follow Back (TLFB)
The TLFB obtains retrospective self-report of substance use by using a calendar and memory prompts to stimulate recall (Sobell \& Sobell, 1992). Quantity and frequency assessments are made using this instrument (e.g., total number of standard drink units, percent of days using) as well as abstinence (yes/no). TLFB yields consistently high test-retest correlations and correlates well with other self-reports and collateral reports (Sobell et al., 2003). The TLFB assesses frequency and amount of substance use over a pre-determined timeframe. TLFB data were collected throughout the trial, and the values reported here represent the TLFB data at end of treatment (week 12).
Time frame: 12 Weeks
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