Electroencephalography during sleep of patients with panic disorder.

Sleep electroencephalograms (EEGs) of subjects with primary panic disorder were compared to those of normal controls matched for age and sex. Significant differences were found between patients and controls in sleep latency, sleep efficiency, and stage 2 sleep duration. No differences were found between the two groups in REM latency. Because depressed patients are known to have reduced latency to REM sleep, these data add support to the hypothesis that panic disorder and depression are distinct disorders.