0012 Morning Misery: Circadian Timing and Negative Affect in a Sample of Adolescents

Abstract Introduction Adolescents with later circadian timing evidence an increased risk for depression. Depressed individuals report higher negative affect (NA), especially in the morning, which may reflect altered circadian timing in NA. Untangling the circadian influences on mood is challenging due to inconsistent operationalizations of circadian timing. This study aims to analyze the associations between three metrics of circadian timing (circadian preference, chronotype, and circadian phase) and daily levels of NA among adolescents. Methods This study analyzed 8 days of ecological momentary assessment (EMA) data among 119 adolescents (54.6% female; mean age 17.3 years). Participants completed sleep diaries with a visual analog scale (VAS) measuring NA (0-100; calm-tense) each morning, and the Positive and Negative Affect Scale–Short Form (PANAS-SF) approximately every 3 waking hours. NA scores were averaged across mornings, evenings, and overall. Circadian preference was assessed by the Composite Scale of Morningness (CSM), chronotype by the Munich Chronotype Questionnaire (MCTQ), and circadian phase by salivary dim light melatonin onset (DLMO; 4pg/ml threshold). We conducted multiple regression analyses to examine circadian preference, chronotype, and circadian phase predicting morning (PANAS, VAS), evening, and overall NA (PANAS), controlling for age, sex, and socioeconomic status. Results Correlations between circadian metrics were low (rDLMO-MCTQ=.20; rDLMO-CSM=.39; rCSM-MCTQ=.27). Greater evening preference predicted higher morning NA (PANAS: p=.026, β=-.21; VAS: p< 0.001, β=-.33) and evening NA (p=.032, β=-.20), but not overall NA (p=.106, β=-.15). These associations were not significant after isolating the Sleep Timing and Activity factor of the CSM. Later chronotype predicted higher NA on the morning VAS (VAS: p=.048, β=.18), but not on the PANAS (p=.756, β=-.03); chronotype did not predict evening NA (p=.259, β=-.11) or overall NA (p=.412, β=-.08). Circadian phase did not predict morning NA (PANAS: p=.841, β=-.02; VAS: p=.552, β=.05), evening NA (p=.625, β=.05), or overall NA (p=.391, β=.03). Conclusion These results highlight the importance of specificity when operationalizing circadian timing and NA, and add to the mixed literature concerning the role of circadian phase in negative mood modulation. Adolescents with later chronotype may be particularly vulnerable to negative mood in the morning. Important next steps involve modeling diurnal patterns of NA and positive affect. Support (if any) R01-AA025626 (Hasler)