Depression or depress may refer to: Psychology Depression (mood), a lack of positive affect Colloquially, Adjustment disorder with depressed mood, previously known as Reactive depression. Clinical depression a clinical diagnosis of a state of intense sadness Melancholic depression a sub-type of clinical depression characterized by an inability to feel pleasure combined with physical agitation, insomnia, or decreased appetite Atypical depression, a cyclical sub-type of clinical depression wh… (More on Depression)