OBJECTIVE: Delayed sleep phase syndrome is a common but little reported
cause of severe insomnia. Since it was first described, few detailed
reports of delayed sleep phase syndrome have appeared, and treatment
methods have not been reviewed. From the literature, the authors provide
diagnostic descriptions and review treatment methods, and from their sleep
disorder clinic, they describe the management and outcome of the largest
series of patients with delayed sleep phase syndrome thus far reported.
METHOD: The authors reviewed all articles with primary data on delayed
sleep phase syndrome published through 1993 and add data from a group of 33
patients at their sleep disorder clinic. RESULTS: Delayed sleep phase
syndrome involves undesirably late bedtimes and arising times, early night
insomnia, and poor morning alertness but lack of insomnia on vacations. The
mean bedtime and arising time for the 33 patients were 4:00 a.m. and 10:38
a.m., respectively. Twenty-five patients were, or had been, depressed.
Individual responses to treatments varied widely. Seventeen patients showed
little treatment response. Delayed sleep phase syndrome had a worse
treatment outcome than other sleep disorders. CONCLUSIONS: Delayed sleep
phase syndrome presents in a heterogeneous manner. In the sleep disorder
clinic population, it was often associated with major depression and was
more resistant to treatment than other sleep disorders. Multiple and varied
treatments are required.