Temporal Tendencies: Exploring the Impact of Chronotype Timing on Youth Depression Risk.

Developmental changes in youth sleep preferences (chronotype) and pubertal development are consequential for youth risk for depression. Previous research has identified individual differences in chronotype in risk for psychopathology. However, little is known regarding how the timing of chronotype may confer risk in youth. This study addressed this gap by examining associations between chronotypal timing and symptoms of depression in youth. Community youth (N = 155; $M_{\mathrm{age}}$ =12.7) completed self-report measures of chronotype, pubertal status and depression every six months for a period of one year (three assessment points). Regression analyses showed that chronotypal timing predicted change in depressive symptoms across six months (b = -0.66, p = 0.019), but not across any other timeframe. Findings suggested that youth experiencing more of a morning preference compared to same-aged peers were at increased risk for later depression across six months. Chronotypal timing continued to predict changes in symptoms of depression controlling for gender (b = -0.63, p = 0.023) and pubertal timing (b = -0.72, p = 0.012). These findings suggest that chronotypal timing is prospectively related to changes in youth symptoms of depression. Results indicate that attention to the timing of normative changes in chronotype is warranted, in addition to mean-level differences.