sleep disorder primary sleep disorder: parasomnia This section includes: - Nightmare Disorder.- The essential feature of this disorder is the repeated occurrence of frightening dreams that lead to awakenings from sleep. - Sleep Terror Disorder.- The essential feature of this disorder is the repeated occurrence of sleep terrors, that is, abrupt awakenings from sleep usually beginning with a panicky scream or cry. - Sleepwalking Disorder.- The essential feature of this disorder is repeated episodes of complex motor behaviour initiated during sleep, including rising from bed and walking about. - Parasomnia Not Otherwise Specified.- This category is for disturbances that are characterized by abnormal behavioural or physiological events during sleep or sleep-wake transitions, but that do not meet criteria for a more specific Parasomnia. DSM-IV-TR (american Psychiatric Association) Disorders characterised by abnormal behavioural or physiological events occurring in association with sleep, specific sleep stages, or sleep-wake transitions. DSM-IV-TR (american Psychiatric Association) 307.47 Nightmare Disorder 307.46 Sleep Terror Disorder 307.46 Sleepwalking Disorder 307.47 Parasomnia Not Otherwise Specified F51.5 Nightmare Disorder F51.4 Sleep Terror Disorder F51.3 Sleepwalking Disorder F51.8 Parasomnia Not Otherwise Specified parasomnias