Sleep and circadian rhythm as developmental antecedents to major mood disorders

Disturbed sleep patterns in children and adolescents may be early signs of risk for depression or bipolar disorder. Inconsistent time of sleep from one night to another may be a particularly strong indicator of risk. We will use devices called actigraphs (which resemble wrist-watches) to objectively measure sleep timing, duration and quality in children and adolescents, including sons and daughters of parents with depression or with bipolar disorder. We will also ask the youth about their sleep, activity, mood and anxiety. At the same time, we will measure sleep in the parents. We will examine the relationships between sleep and mood disorders in parents, sleep duration and regularity in children and later development of mood symptoms in the children. We will compare the information from questionnaires and from actigraphs. Based on the results, we will develop a sleep monitoring procedure with feedback to the participants that can be used as part of preemptive early intervention to reduce the risk of mood disorders.