Sleep-wake rhythm of autistic children

Using a sleep log for 28 days in the summer vacation, 89 autistic children living in a suburb of Tokyo were examined. Only one girl of 13 years showed a tendency of non-24 h sleep-wake syndrome. Most autistic children showed a large variation of total sleep time. Forty per cent of subjects showed 10% or more on coefficient of variation of total sleep time. In the retiring and rising time, many subjects tended to show late retiring and early rising.