Stability of morningness/eveningness and changes in sleep and mental health during mid-adulthood.

: A change toward Eveningness in circadian sleep-wake behavior is generally seen from childhood to adolescence, but less is known about circadian changes during adulthood. Circadian changes during mid-adulthood are of high interest, since Eveningness associates with a range of health-related problems, including psychological symptoms and mental disorders. In this study, we examined the circadian stability across 10 years, from 42 to 52 years of age, and how it is associated with sleep and mental health in a Finnish general population cohort follow-up-based (