 To the investigators knowledge, there is no treatment trial for prazosin use in patients with bulimia nervosa struggling with nightmares, looking at either objective or subjective measures. The investigators plan to probe the effectiveness of prazosin in bulimic patients experiencing nightmares due to PTSD using both subjective and objective measures in order to improve future clinical care. The effects of prazosin on decreasing nightmares and bulimic symptoms on subjective scales and effects on sleep architecture using objective polysomnogram PSG measurements will help inform targeted psychopharmacologic and psychotherapeutic strategies to improve clinical care of bulimic patients struggling with distressing dreams secondary to PTSD. This study will be performed in two phases. Phase A will involve eight participants who will be tested using subjective scales mentioned below. If Phase A data analysis leads to detection of a signal of efficacy 2 more participants will be recruited to participate in phase B of this trial using objective polysomnogram measurements. The results from this project will aid in establishing a fully powered clinical trial for treatment of nightmares in bulimic patients and improve outcomes in this high risk population. 