Last edited on January 15, 2021 Mood Disorders Primer Mood Disorders are a group of mental disorders characterized by prolonged periods of excessive sadness or excessive elevation in mood. Mood Disorders Major Depressive Disorder (MDD) Atypical Depression Geriatric Depression Melancholic Depression Childhood and Adolescent (Pediatric) Depression Perimenopausal Depression Peripartum and Postpartum Depression Psychotic Depression Seasonal Affective Disorder (SAD) Situational (Reactive/Exogenous) Depression Bipolar I Disorder Bipolar II Disorder Bipolar and Related Disorder Due to Another Medical Condition Cyclothymic Disorder Persistent Depressive Disorder (Dysthymia) Premenstrual Dysphoric Disorder (PMDD) Substance/Medication-Induced Mood Disorder Other Specified Bipolar and Related Disorder