Severe depressive pseudodementia with and without dementia.

Recent work has documented the existence of the syndrome of pseudodementia. The authors present four cases of depressive pseudodementia, two without associated dementing illnesses and two that occurred in the context of dementing illnesses. These cases emphasize the difficult nature of differential diagnosis and the profound cognitive impairment that can occur in depressive illness. They also document the coexistence of pseudodementia with "true" dementia. The authors discuss diagnostic and management issues for clinicians treating patients with pseudodementia and depressive illness.