Prevalence and incidence of major depressive disorder in Alzheimer's disease: findings from two databases

Abstract

Background: Reports on the frequency of major depression in Alzheimer's disease are conflicting, some suggesting that it is frequent, others suggesting that it is uncommon.

Methods: We examined the prevalence and incidence of symptom clusters meeting criteria for major depressive disorder (MDD) in two large series of cases diagnosed prospectively by NINCDS/ADRDA criteria as probable or possible Alzheimer's disease. Standard DSM-III-R criteria were employed at one site, the CERAD modification of DSM-III-R criteria at the other. Both sites required the presence of depressed mood on direct patient examination at the time of initial evaluation in order to meet criteria for MDD.

Results: At the center using standard DSM-III-R criteria (n = 329), there was a 0.9% prevalence of symptom clusters meeting criteria for MDD. At the center using the CERAD modification (n = 586), MDD prevalence was 4.8%. Incidence rates at both centers were below 2% per year over 3 years.

Conclusions: We concluded that DSM-III-R MDD is not common in AD patients.