A validation study of depressive syndromes in Parkinson's disease

The validity, sensitivity, and specificity of depressive symptoms for the diagnosis of major depression, minor depression, dysthymic disorder, and subsyndromal depression in Parkinson's disease (PD) were examined. A consecutive series of 173 patients with PD attending a Movement Disorders Clinic underwent a comprehensive psychiatric and neurological assessment. The symptoms of loss of interest/pleasure, changes in appetite or weight, changes in sleep, low energy, worthlessness or inappropriate guilt, psychomotor retardation/agitation, concentration deficits, and suicide ideation were all significantly associated with the presence of the DSM-IV depressed mood criterion for major depression. The symptoms of changes in appetite, changes in sleep, low energy, low self-esteem, poor concentration, and hopelessness were all significantly associated with the presence of the DSM-IV criterion of sad mood for dysthymic disorder. Thirty percent of our sample met DSM-IV diagnostic criteria for major depression, 20% met diagnostic criteria for dysthymic disorder, 10% met diagnostic criteria for minor depression, and 8% met clinical criteria for subsyndromal depression. Patients with either major or minor depression had significantly more severe deficits in activities of daily living, more severe cognitive impairments, and more severe Parkinsonism than patients with either dysthymic disorder or no depression. This study provides validation to the DSM-IV diagnostic criteria for major depression and dysthymic disorder for use in PD. The categories of minor and subsyndromal depression may need further validation.