1069 An Impulsive Night Owl? Longitudinal Associations Between Chronotype, Impulsivity, and Mood Symptoms in an Adolescent Sample

Abstract Introduction Chronotype is an individual’s preference for timing of daily activities relative to clock time. Evening chronotype is associated with higher levels of impulsivity, mood disorder diagnoses, and increased risk for mood disorders. Chronotype and impulsivity may interact to increase an individual’s susceptibility to mood symptoms. However, much work involving chronotype is limited to a single facet of impulsivity as opposed to viewing this construct as multi-faceted. Thus, this study evaluated the associations between chronotype, three factors of impulsivity, and mood symptoms in an adolescent sample. Methods Adolescents (N =164; mean age = 15.11) were recruited from the Philadelphia area as part of a larger longitudinal project investigating predictors of bipolar spectrum disorders. At baseline, participants completed self-report measures of chronotype (Morningness-Eveningness Questionnaire) and mood symptoms (Beck Depression Inventory and Child Mania Rating Scale-Revised). Six-months later, participants repeated mood symptom measures. Participants completed a measure of impulsivity (Three Factor Impulsivity index: two emotion-based and one non-emotion-based) either at baseline or follow-up with the time difference controlled. Hierarchical multiple regression was used to determine main and interaction effects. Baseline mood symptoms, age, and sex were included as covariates. Results Eveningness predicted greater hypo/manic symptoms at follow-up (b = -.09, p .001), controlling for covariates. This same pattern was observed for depressive symptoms but was no longer significant after including covariates, specifically baseline depressive symptoms. One emotion-based impulsivity factor, feelings trigger action, significantly moderated the association between chronotype and hypo/manic symptoms such that greater levels of impulsivity strengthened the association between eveningness and greater hypo/manic symptoms (b = -.07, p .05). The other two forms of impulsivity (pervasive influence of feelings and lack of follow-through) did not significantly moderate these associations. Conclusion Eveningness predicted hypo/manic symptoms in an adolescent community sample. An externalizing form of emotion-based impulsivity strengthened the association between evening-type and hypo/manic symptoms, emphasizing the importance of viewing impulsivity through a more granular lens. Additional longitudinal work is needed to clarify the role of chronotype and multi-faceted impulsivity in the pathogenesis of mood disorders. Support (if any) National Institute of Mental Health R01 MH 126911 to Lauren Alloy.