The spectrum of depressive pseudo-dementia.

Depressive disorder causes cognitive symptoms. In the case of severe cognitive symptoms or when psychometric procedures measure cognitive decline in the range of dementia, depressed patients may be diagnosed as Depressive Pseudo-Dementia (DPD). There is no data that depressive disorder can cause dementia without coexisting depressive symptoms. The latter symptoms are frequently overseen because cognitive symptoms are equated with organic brain disease. There are typical neuropsychological features of cognitive decline in depressive disorders, like psychomotor retardation and the slow-start phenomenon. Most patients referred to as DPD, suffer from depression-induced cognitive symptoms outside the range of dementia, but complain of memory disturbance and inability to think or concentrate. The diagnosis of DPD draws attention to a problem in the diagnosis of psychiatric disorders in the elderly: Old people suffering from depression are at particular risk of being labelled as demented. The most important step to diagnose depression causing dementia is the search for signs and symptoms of affective disorder even after having found cognitive symptoms.