The cognitive behavioral therapy is conducted in individual sessions, approximately 50 minutes in duration. The therapy is manual-guided, focused on the PTSD symptoms only, and designed to work in conjunction with the addiction treatment program services. The therapy is offered in weekly sessions, for 12-14 total sessions. At monthly intervals, the subject will complete the RTS and a trauma event checklist based on the PCL, and will be tested for alcohol (breathalyzer) and drug use (urine screen). The subject will also complete the Working Alliance Inventory (WAI - client version) after the second PTSD therapy session.