Chronically depressed mood that occurs for most of the day more days than not for at least 2 years. the required minimum duration in children to make this diagnosis is 1 year. during periods of depressed mood, at least 2 of the following additional symptoms are present: poor appetite or overeating, insomnia or hypersomnia, low energy or fatigue, low self-esteem, poor concentration or difficulty making decisions, and feelings of hopelessness. (dsm-iv)