atypical depressive disorder A mood disorder that is characterized by mood reactivity (paradoxical anhedonia) and positivity, significant weight gain or increased appetite ("comfort eating"), excessive sleep or somnolence (hypersomnia), a sensation of heaviness in limbs known as leaden paralysis, and significant social impairment as a consequence of hypersensitivity to perceived interpersonal rejection. Atypical depression DOID:12294 ICD9CM:296.82 SNOMEDCT_2010_1_31:191659001 SNOMEDCT_2010_1_31:192371004 SNOMEDCT_2010_1_31:277538003 UMLS_CUI:C0154437 disease_ontology mood disorder