Association between premorbid history of depression and current depressionin Alzheimer's disease

The relationship between a premorbid history of depression and the depressi ve syndrome in Alzheimer's disease (AD) remains equivocal. In the current s tudy, we compared the prevalence of depression among patients with and with out a history of mood disturbance prior to the onset of dementia, The sampl e comprised 243 AD outpatients evaluated consecutively at a university-affi liate memory disorders center, The results indicated that a positive histor y of depression was more common among patients with current depression comp ared to those without current depression (23% vs 11%, Fisher's Exact Test, P = .03). This relationship remained significant after controlling for the effects of age, education, gender, ethnicity, and level of cognitive impair ment (odds ratio = 2.6, 95% confidence interval = 1.01-6.61, P = .04), Neit her gender nor the interaction of gender and history of depression was show n to confer risk for current depressive symptoms. The present investigation suggests that premorbid depression may alter the risk for mood disturbance in AD.