Paroxetine Treatment in Outpatients With Comorbid PTSD and Substance Dependence

Pharmacotherapy has demonstrated efficacy in a number of controlled trials in the treatment of PTSD. The selective serotonin reuptake inhibitors have proven particularly useful in treating this disorder. Currently there are two selective serotonin reuptake inhibitors (Zoloft® and Paxil®), that have been FDA approved for treating PTSD. Coincidentally, this same class of medications has also been shown to have efficacy in some trials in decreasing alcohol consumption in heavy drinkers. The goal of the proposed study is to preliminarily investigate the efficacy of Paxil® (paroxetine), in decreasing symptoms of PTSD as well as decreasing substance use, in individuals with concurrent substance dependence and PTSD. The type of paroxetine used in this trial will be Paxil CR®, which is a sustained release formulation of paroxetine, which has fewer side effects and greater tolerability. This is a particularly important issue in substance using populations because medication compliance is generally poor. Two specific hypotheses will be tested. 1) Individuals who receive Paxil CR® will have a greater improvement in their PTSD symptoms (based on CAPS-2 and CGI) than those who receive placebo. 2) Individuals who receive Paxil CR® will have greater improvement in their substance use outcomes (based on UDS and TLFB) than will those who receive placebo.