First night effects in good sleepers and sleep-maintenance insomniacs when recorded at home.

Home sleep recordings were conducted over four consecutive nights with 12 good sleepers and 12 sleep-maintenance insomniacs. Good sleepers showed decreased sleep efficiency and increased min awake after sleep onset on night 1. Insomniacs showed extended latency to onset of the first REM period and decreased REM in the first third of the initial recording night. Good sleepers and insomniacs reported no significant differences in adequacy of sleep between the first and subsequent sleep nights.