dysthymic disorder 300.4 http://purl.bioontology.org/ontology/MESH/D019263 http://purl.obolibrary.org/obo/DOID_12139 http://purl.obolibrary.org/obo/NCIT_C34562 A mood disorder that involves the presence of a low mood almost daily over a span of at least two years. 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. F34.1 dysthymic disorders mood disorder disorder