Department of Defense PTSD Adaptive Platform Trial - Intervention A - Fluoxetine

This study is part of a larger US Department of Defense trial testing treatments for PTSD in military service members and veterans. This specific arm tests fluoxetine (Prozac) — a commonly used antidepressant — to see how well it reduces PTSD symptoms in this population. **You may be eligible if...** - You meet the general eligibility criteria for the master PTSD trial (NCT05422612), which typically includes being a military service member or veteran with a PTSD diagnosis - You have not recently been treated with fluoxetine specifically for PTSD at a standard dose (20 mg daily for at least 4 weeks) **You may NOT be eligible if...** - You recently received fluoxetine at 20 mg/day for at least 4 weeks for PTSD treatment - You do not meet the general criteria of the master PTSD trial Talk to your doctor to see if this trial is right for you.