Developing multicomponent chronotherapeutic interventions for emerging adults with delayed sleep timing.

Emerging adulthood (ages 18-25) is the developmental peak for delayed sleep and circadian timing and a period of risk for psychopathology. The current study compared two chronotherapeutic interventions targeting delayed sleep timing in emerging adults with no-to-moderate depression. Study 1 (N = 21, ages 18-22, 43% women) was a 2-week morning bright light therapy intervention. Study 2 (N = 15, ages 18-25, 86% women) supplemented 2 weeks of morning bright light therapy with a personalized sleep-wake timing advance and blue-light blocking glasses for 2 h prior to bedtime. After 2 weeks, circadian phase (B = 0.1; SE = 0.1; p = 0.46) and depression symptoms (B = -0.2; SE = 0.1; p = 0.05) did not significantly change in Study 1. In contrast, circadian phase advanced by ~35 min (B = -0.4; SE = 0.2; p = 0.03) and depression symptoms decreased (B = -1.2; SE = 0.3; p < 0.001) in Study 2. Future work in larger, randomized controlled trials with rigorous adherence monitoring is needed to confirm the effectiveness of these interventions.