Rewrite This study is comparing the effectiveness of two psychotherapy approaches for the treatment of combat veterans that have chronic post-traumatic stress disorder (PTSD): cognitive-behavioural therapy (CBT) and psychodynamic psychotherapy (PDT). These are the most common treatments used in the treatment for combat veterans that suffer from PTSD. Both of these treatments used to treat PTSD expose these patients to the source of their trauma and reflecting on the traumatic event. This study utilized an effectiveness measure to determine the effectiveness of each treatment. 243 male participants (veterans) that were seeking treatment who had a diagnosis of chronic combat-related PTSD were used. This study was utilized to determine which treatment option provided the most effective outcomes in the treatment of PTSD. The process was interviews, post-treatment assessments, follow-ups, and analysis were conducted on the participants. They utilized a self-reported questionnaire to determine a participants level of functioning. In this study it was determined that both CBT and PDT treatments are effective for treating PTSD in veterans suffering from chronic PTSD. Both therapies showed reductions in PTSD and depression symptons and showed improved functioning levels after a 8-12 month follow up. Behaviourism was the learning theory present in this study as