Wrist activity rhythm and sleep diary of delayed sleep phase syndrome.

Wrist activity rhythm and sleep diary data in a case of delayed sleep phase syndrome were investigated. The sleep self-estimation was nearly compatible with the activity levels of the actigraph. The actigraphic data were also analyzed. The subject's most fixed period of activity was 24.31 h, and acrophase (time of day) that fixed the data to a 24 h period was 03.25 h. The subject has had reversed night and day sleep patterns for more than 7 years. It was very difficult to advance the sleep phase when the delayed phase has been continuous long-term under the state of poor social cues.