While there have been advances in understanding post-traumatic stress disorder (PTSD) as a disorder and its biological features, unfortunately only one out of five traumatized persons with PTSD reach remission after cycling through evidence-based and/or FDA-approved medications. This is especially unfortunate given that people with PTSD are often from vulnerable populations, or those whose professions entail personal sacrifice. It is clear that new serotonergic antidepressants and atypical antipsychotics will not be sufficient to fix this gap, and new mechanisms of action need to be tested. In the current proposal, the investigators test the hypothesis that mixed amphetamine salts (brand name Adderall), FDA-approved for treating attention deficit hyperactivity disorder (ADHD), can improve PTSD outcomes.