Depression is a general lowering or reduction, for example of mood, activity, or functionality:
; Psychology and mood:
:* Depression , a personality facet in Revised NEO Personality Inventory.
:* Depression , a common term for a sad or low mood or emotional state, or the loss of pleasure
:* Clinical depression, or major depressive disorder, a clinical term for a state of intense sadness, melancholia or despair that has advanced to the point of being disruptive to an individual's social functioning and/or activities of daily living. Subtypes of clinical depression:
:::* Melancholic depression, characterized by the inability to find pleasure in positive things combined with physical agitation, insomnia, or decreased appetite
:::* Atypical depression, a common long term cyclical form of depression in which the individual can feel enjoyment, eat, and sleep, but there is significant lethargy, a 'leaden' feeling, and a strong response to rejection-related issues
:::* Psychotic depression, in