Temporal pathways between circadian rhythm, depression and anxiety in the transition from adolescence to early adulthood

Background: Sleep and circadian rhythm problems intertwine with affective disorders. Adolescents are particularly vulnerable to developing sleep and affective problems. Yet, the temporal pathways between circadian rhythm, depression and anxiety in the transition phase from adolescence to early adulthood are not fully understood. Methods: 233 adolescents (76 % females) participated at two time points (T1 and T2) at an interval of 19-months (aged 16.8 and 18.4 years). We used The Beck Depression Inventory-II, Generalized Anxiety Disorder Assessment, GENEActiv actigraphy across 8 days (delayed sleep phase (DSP), sleep duration, midpoint, and regularity), and iButton 1922L thermologgers across 3 days (intrinsic circadian period length, amplitude, and mesor). Results: A shorter sleep duration at T1 associated with an increase in affective problems at T2, and affective problems at T1 associated with an increase in sleep irregularity at T2. A longer circadian period at T1 associated with an increase in males' affective problems at T2. Moderate to severe depression and anxiety at T1 associated with a 2.69-fold risk (95 % CI 1.38-5.26, p = 0.004) and 2.11-fold risk (95 % CI 1.04-4.25, p = 0.038) of poor sleep quality at T2. Moderate to severe generalized anxiety associated with a 3.17-fold risk (95 % CI 1.35-7.41, p = 0.008) of DSP at T2. Limitations: The follow-up period is short. Conclusions: The results revealed bidirectional temporal links between sleep and affective problems. Novel observations include a heightened risk of future DSP following a current anxiety disorder and a heightened risk of affective problems following a longer circadian period measured from the 24-hour temperature variation in males.