Sleep impairment is the most often reported of the 17 PTSD symptoms and is considered one of the most refractory to treatment. This study proposes the use of sleep-directed hypnotherapy to address sleep issues as a complementary element to empirically supported Cognitive Processing Therapy (CPT) in treating PTSD in sexual and physical assault survivors. Specifically the study aims to: 1) compare the results of sleep-directed hypnosis plus CPT with CPT only, 2) to assess the relationship between sleep and PTSD symptoms, 3) to examine relationships between sleep improvement, PTSD symptom improvement, and the therapeutic elements (hypnosis, exposure, cognitive therapy) to determine mechanisms of action in the intervention, 4) to assess the relationship between sleep and physical reactivity to trauma-related cues and to other stimuli.