Despite a philosophical belief in the health benefits of balanced participation in everyday activities, occupational therapists have devoted scant research attention to the relationship between mental health and activity participation in childhood and adolescence. Time use studies offer valuable insights into this relationship. In this literature review the methodologies employed in time use studies are described, and empirical findings linking depression to the distribution of time to leisure, productive and self-care activities, and sleep are then outlined. The relevance of findings to occupational therapy assessment and intervention is discussed. Therapists are challenged to further research the area, as gaining thorough knowledge of young people's time use has implications for both professional practice and broader public health policy.