Recent studies have linked depression with Alzheimer’s disease. The question is if the depression is a result of the Alzheimer’s or a the cause of it.

Robert S. Wilson, PhD, Rush University Medical Center, Chicago, and colleagues studied 917 older Catholic nuns, priests, and monks–all of which were free from signs of dementia.

At the beginning of the study participants completed a 10-item scales assessing their symptoms of depression, then were re-evaluated annually.

• 54% reported no symptoms of depression symptoms.
• 24% reported one occurrence of depression symptoms.
• 10% reported two occurrences of depression symptoms.
• 6% reported three occurrences of depression symptoms.

In the pursuing years 190 individuals developed Alzheimer’s disease. Those with more occurrences of depression symptoms were more likely to develop Alzheimer’s. However, those who did develop Alzheimer’s disease did not have an increase of depressive symptoms.

Researchers note that depression may be associated with changes in the brain that reduce its resistance to dementia. Understanding the link between depression and dementia could lead to new approaches to delaying dementia onset.