Twenty patients who had been insomniac since childhood were compared with 39 who had become insomniac during adult life. The childhood-onset insomniacs took longer to fall asleep, slept less, and showed excessive amounts of REM sleep without eye movements. Adult-onset insomniacs showed more restless sleep. No differences between childhood- and adult-onset groups were found on personality inventories, but those with childhood-onset insomnia reported more evidence of possible "soft" neurological impairment.