Increased nocturnal activity and impaired sleep maintenance in abused children.

Objective: Previous studies have suggested that sleep disturbance may be the "hallmark of posttraumatic stress disorder," although several investigations have failed to find evidence for sleep disruption. The purpose of this study was to determine whether intense averse stimulation during early development, in the form of physical and/or sexual abuse, led to disruption of sleep and nocturnal activity.

Method: Nineteen prepubertal children with documented abuse were compared with 15 nonabused normal controls and 10 depressed children. All subjects received a complete semistructured diagnostic interview. Ambulatory activity monitoring was used to evaluate sleep-related activity for three consecutive nights. Data were analyzed for nocturnal activity and algorithmic estimation of sleep initiation and continuity.

Results: Abused subjects were twice as active at night as normal and depressed children, and abused subjects emitted a greater percentage of their total daily activity during the night. Actigraph-derived sleep measures suggested that abused children had prolonged sleep latency and decreased sleep efficiency. Physically abused children had more impaired sleep efficiency than sexually abused children.

Conclusion: Abused children have higher levels of nocturnal activity than normal controls or depressed children and appear to have more difficulty falling and staying asleep. Physical abuse appears to be the salient factor rather than posttraumatic stress disorder.