The main hypothesis being tested is that a cognitive behavioral therapy (CBT) for posttraumatic stress disorder (PTSD) can improve treatment retention and outcomes for both posttraumatic stress and substance use disorders. The investigators have completed the Stage I Safety & Practicality Study, Feasibility Study and Pilot Randomized Controlled Study (comparing CBT for PTSD to versus a control condition) and for all studies found that CBT for PTSD was safe and effective in reducing PTSD symptoms, improving retention, and in reducing substance use. The present study proposes to continue testing the hypotheses by evaluating and comparing the PTSD, retention and substance use outcomes resulting from CBT versus a control condition and to treatment as usual. This is termed a "Stage II Efficacy Study" of behavioral therapy development and requires comparing the investigational treatment (CBT) with a control treatment, within the context of addiction treatment-as-usual (intensive outpatient programs). This is a larger randomized controlled trial in response to the outcomes of the pilot trial. The proposed research will evaluate the efficacy of a relatively simple, manual-guided cognitive behavioral therapy (CBT) for PTSD. CBT for PTSD has been designed and developed for delivery by counselors employed in community addiction treatment programs and offered in conjunction with standard community addiction treatment. Outpatients at each of 7 community addiction treatment programs, diagnosed with current PTSD will be randomly assigned to receive either: 1) CBT for PTSD in conjunction with standard treatment-as-usual (TAU) (n=76); 2) A manual-guided individual addiction counseling (IAC) adapted from the Individual Drug Counseling Manual in conjunction with TAU (n=76); or 3) TAU (n=76) without additional individual treatment for either PTSD or substance use disorders. Treatment will be delivered by frontline counselors from and onsite in the addiction treatment programs.