The diagnosis of depression involves three components: (1) eliciting the symptoms that form a depressive episode; (2) determining their severity and the functional impairment that they cause; and (3) mapping their longitudinal course over the duration of an episode, as well as the illness as a whole. Depressive episodes usually last several weeks and can last several months if untreated. After remission, symptoms can re-emerge (relapse) before functional recovery and even then, further long-term episodes of depression (recurrence) remain likely. Scores and categories drawn from UK National Institute for Health and Care Excellence.25 PHQ-9=Patient Health Questionnaire-9. *Hopelessness is only specified in ICD-11 and not in DSM-5-TR.