Seasonality of human sleep: Polysomnographic data of a neuropsychiatric sleep clinic

This study examined seasonal variations in sleep architecture using data from 188 patients with neuropsychiatric sleep disturbances. Findings showed longer total sleep times and more REM sleep in winter compared to summer, with slower wave sleep (deep sleep) stable except for a decline in autumn. REM latency (time to enter REM sleep) was shorter in autumn and winter. These patterns suggest that human sleep is influenced by seasonal changes, even in urban environments with artificial lighting, which may impact cognitive function and overall well-being.

Align sleep schedules with seasonal changes by allowing for longer sleep in winter, such as going to bed earlier to meet natural increases in sleep needs. This could help maintain optimal cognitive performance and mood, especially during darker months. These findings primarily apply to individuals with sleep disorders.