Circadian rhythm sleep disorders: a brief review with special reference to long-term follow-up

This article reviews the hygiene of new sleep disorders such as delayed sleep phase syndrome (DSPS) and non-24-hour sleep-wake syndrome which are classified as the circadian rhythm sleep disorders in the International Classification of Sleep Disorders (ICSD) published in 1990. It was clear in this study that these sleep schedule disturbances developed by preference in adolescence and youth, and the prevalence of DSPS in this generation was presumed to be 0.25-0.4%. Patients with certain disorders, such as entrainment to external time cues, were treated with non-pharmacological interventions and/or pharmacological agents. These therapies were effective in some cases when each was administered alone, but their effectiveness in other cases was not evident until two or more of therapies were used in combination. The prognosis of these two syndromes was significantly positive, particularly in the adolescent cases, suggesting the benefits of early discovery and treatment.