Rest-activity cycles in childhood and adolescent depression.

Objective: To quantify circadian rhythms in rest-activity cycles in depressed children and adolescents.

Method: Rest-activity cycles were evaluated by actigraphy over five consecutive 24-hour periods in 100 children and adolescents, including 59 outpatients with major depressive disorder (MDD) and 41 healthy normal controls. Total activity, total light exposure, and time spent in light at more than 1,000 lux were averaged over the recording period for each participant.