ecurrent nightmares are a signature feature of PTSD". It states that sleep phobia is common, partly due to dread of nightmares: "Recurrent nightmares, sleep phobia, and chronic insomnia provide a strong conditioning context for associating the bedroom with anxious arousal. This becomes even stronger for sexual assault victims who may have experienced the traumatic event in the bedroom. Thus, patients with PTSD have difficulty in relinquishing a defensive posture that is critical for inducing normal healthy sleep.