Total sleep deprivation study in delayed sleep-phase syndrome.

Delayed sleep-phase syndrome (DSPS) is characterized by delayed sleep onset against the desired clock time. It often presents with symptoms of sleep-onset insomnia or difficulty in awakening at the desired time. We report the finding of sleep studies after 24 h total sleep deprivation (TSD) in a 28-year-old DSPS male patient. He had characteristics of mild chronic DSPS, which may have been precipitated by his frequent night shift assignments. The TSD improved the patients sleep latency and efficiency but all other sleep variables showed marked differences.