Paroxetine Treatment in Outpatients With Comorbid PTSD and Substance Dependence

Participants who meet all inclusion and no exclusion criteria will be randomized with a 1:1 ratio to receive either Paxil CR or placebo for 12 weeks. Medication will be initiated at 12.5mg/day and will be increased weekly as tolerated to a maximum dose of 50mg/day. Participants will be seen weekly and will be assessed for side effects, substance use since last visit, urine drug screen, breathalyzer readings, vital signs and symptoms of PTSD (TOP-8)at each visit. The Davidson Trauma Scale will be completed every two weeks, and the CAPS-2 and MADRS will be completed monthly. Those who complete the first 12 weeks of double-blind study medication will be eligible to receive open label medication for an additional 12 weeks. Medication will be initiated at 12.5mg and increased every 3 days as tolerated to the terminal dose in the double-blind phase, then adjusted as needed. Participants will come in for assessments every two weeks of the open-label phase. Blood will be drawn for blood chemistries and hematology at screening and weeks 12 and 24. Urine pregnancy tests will be performed for women of childbearing potential at baseline and again at weeks 4, 12 and 24.