Depressive Symptoms Not Linked to Alzheimer's Risk
But individuals with a history of depression have increased risk
TUESDAY, April 8 (HealthDay News) -- Elderly individuals with depressive symptoms or with no increase in depressive symptoms do not have an increased risk of developing Alzheimer's disease, although those with a history of depression are at increased risk, researchers report in two studies published in the Archives of General Psychiatry and Neurology in April.
In the Archives of General Psychiatry study, Robert S. Wilson, Ph.D., from Rush University Medical Center in Chicago, and colleagues evaluated depressive symptoms, mild cognitive impairment and Alzheimer's disease for up to 13 years in 917 Catholic nuns, priests and monks (aged 56 to 102 years) without dementia at baseline. The investigators found no increase in depressive symptoms in the 190 individuals who developed Alzheimer's disease or in those who developed mild cognitive impairment.
In the April 8 issue of Neurology, M.I. Geerlings, Ph.D., from University Medical Center Utrecht in the Netherlands, and colleagues examined the association between depression, depressive symptoms, structural brain changes and risk of Alzheimer's disease in 503 individuals (aged 60 to 90 years) without dementia. They found that 33 subjects developed Alzheimer's disease during an average follow-up of six years, and that a history of depression increased the risk of developing Alzheimer's. The risk was higher for those with early onset (under 60 years old) depression versus late-onset depression (hazard ratio 3.76 versus 2.34).
"History of depression, and particularly an early onset, but not presence of depressive symptoms increased the risk of Alzheimer's disease. This risk was not mediated by smaller hippocampal or amygdalar volumes," Geerlings and colleagues conclude.