[Diagnostic criteria of depressive pseudodementia]

Ten patients fulfilling the DSM III (A, B, C, D) criteria for both dementia and major depression and presenting the diagnostic dilemma of depressive pseudodementia were included in a prospective study in search of indices for the differential diagnosis of depressive pseudodementia (DPSD) and organic dementia (OD). Patients were assessed with the Hamilton Depression Rating Scale (HDRS), the Blessed Dementia Rating Scale (BDRS), the Wells's criteria, the Mini Mental State (MMS), computerized tomography (CT scan) of the brain, the dexamethasone suppression test (DST), total plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) and sleep electroencephalograms (EEG). Patients suffering from DPSD were defined as showing an improvement higher than 50% in both the HDRS et BDRS scores following adequate antidepressant treatment. Wells's criteria, MMS scores, CT scan and DST do not contribute to the separation of DPSD (n = 6) and OD (n = 4). On the contrary, plasma MHPG levels higher than 35 ng/ml and EEG measures of sleep structure and REM sleep significantly differentiate the two groups.