Depression and dementia: comorbidities, identification, and treatment.

Depression is a highly prevalent concomitant of dementia. Concurrent depression (DD) can meet full criteria for a disorder or take the form of a depressive syndrome. Although phenomenologic overlap can confound diagnosis, careful assessment demonstrates that a true depressive component is present in a substantial percentage of dementia cases. DD has been associated with excess disability, increased caregiver burden, and greater mortality. Efficacy studies have demonstrated high placebo response rates, indicating transience of many depressive symptoms, and adverse cognitive effects of older antidepressants. Studies demonstrating that new antidepressants can be efficacious and improve cognitive functioning are reviewed.