Retarded depression is a category of depression characterised by slow thinking and behaviour (psychomotor retardation). It is contrasted with agitated depression (characterised by heightened psychomotor activity). Though some clinicians continue to use the term, as a diagnostic category of depression it has largely been displaced by those in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders or the World Health Organisation ICD.
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Retarded depression Wikipedia(Text) CC BY-SA