Self-reported and actimetry-based cluster analysis of mood rhythmicity profiles in adolescents with and at risk for Major Depressive Disorder.

Greater self-perceived rhythmicity of mood-related symptoms and behaviors has been associated with depressive symptoms in the general public. We aimed to evaluate differences in adolescents at risk for or with a diagnosis of major depressive disorder (MDD) regarding perception of symptom rhythmicity and actimetry parameters. In this cross-sectional study, 96 adolescents were stratified into three groups based on either a diagnosis of MDD or on a composite score for the risk of developing depression: MDD, high risk (HR), and low risk (LR). Participants completed questionnaires regarding depressive symptoms (Mood and Feelings Questionnaire for adolescents) and self-perceived mood rhythmicity (Mood Rhythm Instrument for Youth - MRhI-Y). Actimetry data were collected for 10 continuous days and Non-Parametric Circadian Rhythm Analyses were performed. The MDD group reported higher MRhI-Y total scores, particularly in affective symptoms compared to both other groups. In spite of actimetry variables that did not correlate with MRhI-Y total scores, cluster analysis using MRhI-Y and actimetry revealed three distinct profiles corresponding to all groups. Identifying rhythmicity in mood-related behaviors in adolescents may help distinguish different groups at-risk for MDD and in a current depressive episode. Understanding these patterns could inform early interventions, potentially preventing the onset of the disorder in susceptible individuals.