Abstract: ObjectiveTo verify the homology hypothesis of depression and insomnia.Methods All-night physiological signals of electroencephalogram (EEG), electrosculogram (EOG) and electromyogram (EEG) of 30 depression cases and 30 insomnia cases were recorded and analyzed with polysomnogram.ResultsThe rapid eye movement (REM) sleep of depression patients was more active, and there was a significant difference in all REM indexes compared with insomnia cases (P<0.01). Characteristics of insomnia cases were poor sleep continuity, easy wake after sleep-onset, and depression of slow wave sleep and REM sleep. There was no slow wave sleep in some insomnia cases.Conclusion The sleep patterns of depression and insomnia are different, REM sleep is hyperactive in depression; non-REM sleep is disturbance in insomnia.

Key words: depression, insomnia, polysomnogram