Grant: Master's Award: Canada Graduate Research Scholarships - Master's program

Background: Major depressive disorder (MDD) is a highly prevalent mental health disorder among youth, which profoundly impacts daily functioning. Anhedonia, the loss of interest or pleasure in activities, is a symptom of MDD that predicts more severe outcomes, such as higher suicidality, poorer treatment response, and longer time to remission. Anhedonia also tends to persist outside of depressive episodes. While physical activity has been shown to alleviate depressive symptoms and prevent MDD recurrence, no research to date has examined the relationship between anhedonia and physical activity in youth. Objective: This study aims to investigate the association between accelerometry-measured physical activity and self-reported anhedonia in youth with a history of MDD. Methods: The proposed study will analyze existing data from a longitudinal cohort of youth aged 12-21 (N = 156) with a current or past diagnosis of MDD. Physical activity was measured objectively using a wrist-worn accelerometer. Anhedonia was measured using items from two established depression rating scales. Current MDD was interviewer-assessed using validated depression measures. A linear mixed-effects model will be used to examine anhedonia as a predictor of physical activity. An exploratory analysis will examine whether anhedonia exerts effects independent of current MDD status, and a moderation analysis will examine the role of gender. Significance: Youth with anhedonia experience many adverse outcomes, underscoring the need for focused intervention. Understanding the health behaviours, such as physical activity, of these at-risk youth can inform clinical practice. This may involve integrating physical activity interventions to support health promotion and prevent MDD recurrence.