Depression may be Linked to Rapid Decline in Alzheimer’s Disease

February 7th 2006

The Brain

People that suffer from depression may be more likely to have a more rapid decline in Alzheimer’s disease (AD). A study published in the February issue of Archives of General Psychiatry states that “People with a lifetime history of major depressive disorder (MDD) may be more likely to be diagnosed with AD.”

Previous studies have linked depression and Alzheimer’s disease. Both MDD and AD affect the brain’s memory related temporal lobes. Also, MDD is likely to cause atrophy of the hippocampus. The hippocampus is the area of the brain where plaques and tangles form in a patient with AD, according to the authors.

Researchers at the Mount Sinai School of Medicine, New York, compared the brains of 44 AD patients with a history of depression to 51 without depression. Of this group, 32 were men and 63 were women. On average age of death was 81 years.

They found that patients with a history of depression had more tangles and plaques in the hippocampus than those without. In fact “People who were depressed at the time they were diagnosed with AD had even more pronounced changes in their brains than those whose depression occurred earlier or later”, according to the authors.

The cognitive analyses conducted while the participants were alive with AD shed light on this connection. Patients who suffered from depression also experienced a more rapid decline into dementia compared to those who did not have it.

Michael A. Rapp, M.D., Ph.D., Mount Sinai School of Medicine said "These results have great clinical significance in that the identification of potential mechanisms that link geriatric MDD as a treatable risk factor to neuropathological changes in AD may lead to the development of differential intervention and prevention strategies for AD. Such specific interventions would be especially needed since geriatric patients with MDD with cognitive impairment may have less favorable treatment outcomes." Gene Mutation concerning Parkinson's and Alzheimer's Diseases