A sleep diary and questionnaire study of naturally short sleepers

Whereas most people require more than 6 h of sleep to feel well rested, the re appears to be a group of people who can function well on between 3 and 6 h of sleep. The aims of the present study were to compare 12 naturally sho rt (3-6 h) sleepers (9 males 3 females, mean age 39.6 years, SD age 10.1 ye ars) recruited by a media publicity campaign with age, gender and chronotyp e matched medium length (7-8.5 h) sleepers on various measures. Measurement instruments included diaries and questionnaires to assess sleep duration a nd timing, as well as questionnaire assessments of sleep pathology, morning ness-eveningness, extroversion, neuroticism, pathological daytime sleepines s, subclinical hypomania, optimism, depressive symptoms, exercise, and work habits. Few measures showed reliable differences between naturally short s leepers and controls except the obvious ones related to sleep duration. The re was, however, some evidence for subclinical hypomanic symptoms in natura lly short sleepers.