Differences in psychosocial factors and sleep study findings between delayed sleep-wake phase disorder and hypersomnia in teenagers.

Central hypersomnia (HS) and delayed sleep-wake phase disorder (DSWPD) appear commonly in adolescents, and they severely reduce quality of life and have an enormous impact on academic performance and other aspects of development. Although these disorders are thought to be considerably different in etiology, it is sometimes difficult to distinguish them because of their similar clinical features. This study aimed to compare psychosocial factors and sleep study findings between HS and DSWPD in teenagers. The clinical data of 89 teenagers who visited the psychiatric section of the Sleep Medicine Center of Nihon University Itabashi Hospital from January 2013 to December 2019 were analyzed. Psychosocial factors were evaluated at the first visit, and polysomnography (PSG) and the multiple sleep latency test (MSLT) were performed for patients deemed to require definitive diagnosis. Compared with patients with HS, those with DSWPD had a higher rate of mother's employment, introversion, adjustment problems, events that triggered the disorder, concurrent mental disorders, habitual lateness, and difficulty attending school or work. PSG did not show any differences in sleep parameters between the two disorders, except for sleep latency. On the MSLT, sleep latency was shorter in those with HS on the second, third, and fourth tests. The present results suggest that focusing on psychosocial factors could be useful for differential diagnosis of the two disorders that appear commonly in adolescents.