TABLE 1

ICD-9 Code–Based Definition of Depression

ICD-9 CodeDescription
296.2Major depression, single episode
296.3Major depression, recurrent episode
296.82Atypical depression disorder
298.0Depressive type psychosis
300.4Neurotic depression
308.0Predominant disturbance of emotions
309.0Adjustment reaction, brief depressive
309.1Adjustment reaction, prolonged depressive
309.4Adjustment reaction, with mixed disturbance emotions
311Depressive disorder not otherwise classified