Concurrent depression and dementia: implications for diagnosis and treatment.

The need to distinguish between depression and dementia is well recognized and has been much discussed, but the coexistence of the two illnesses has received less attention. Three cases are presented which corroborate previous reports of the coexistence of dementia and depression but also raise other issues. It is suggested that this diagnosis should not be viewed as an "either/or" decision, but that each diagnosis should be considered independently. The cases illustrate that the type of depression present may vary and that an accurate assessment of dementia may be possible only after depressive symptoms have abated. Other issues encountered in this clinical situation are discussed.