Dementia of depression in Parkinson's disease and stroke

Depression is a frequent finding in patients with neurological disorders. These depressions, however, have similar phenomenology, duration, biological markers, and response to treatment as depressions in patients with no known brain injuries (i.e., functional depression). In the present article, we review evidence that suggests the dementia of depression exists among severely depressed patients with cerebrovascular lesions or Parkinson's disease (PD). We conclude that: a) in patients with either stroke lesions or PD, depression is significantly associated with cognitive deficits; b) this association is only true for patients with major depression (i.e., it is not present in patients with minor depression); and c) patients with poststroke depression and patients with PD and depression have a severity and profile of cognitive deficits similar to those found in patients with primary major depression.