endogenous depression

noun Psychiatry.

a severe form of depression usually characterized by insomnia, weight loss, and inability to experience pleasure, thought to be of internal origin and not influenced by external events.

Origin of endogenous depression

First recorded in 1960–65

Also called melancholia.

endogenous depression in Medicine

A group of symptoms that resemble depression but are not precipitated by a stressful experience, especially psychomotor agitation or retardation, insomnia and early morning awakening, weight loss, excessive guilt, and lack of reactivity to one's environment.