16. "History of Depression as a Risk Factor for Alzheimer's Disease"

Summary: Speck says that if a person has deep rooted depression, there is a high risk that chemical imbalance will affect the possibility of getting Alzheimer's as a result. However, as a rebuttal, the study did find that if patients with AD did not have depression within 10 years prior of being diagnosed, the risk and rate of getting Alzheimer's was not directly correlated.

Key Facts:
"Depression sometimes coexists with Alzheimer's disease and may cause difficulty in diagnosis in the early stages of AD."
"Depression could be the result of chemical changes in the brain; medications have been developed that modify brain chemistry and alleviate depression."
"For depression reported to have occurred 10 or fewer years before the reference year, and for 'depression limiting activities,' we found little or no increase in risk for AD."
"The finding the depression occurring 10 or more years before the onset of AD increases the risk is generally consistent with earlier studies that found a positive association between AD and depression."
"Among more aged persons, the experience of loss and grief is likely to be more common and may activate normal coping mechanisms. Occasionally, however, persistent major depression may follow these grief reactions."

Speck, Carl, Walter Kukull, Daniel Brenner, James Bowen, Wayne McCormick, Linda
Teri, Meredith Pfanschmidt, Jill Thompson, and Eric Larson. "History of Depression as a Risk Factor for Alzheimer's Disease." JSTOR. Lippincott Williams & Wilkins, 1 July 1995. Web. 31 Jan. 2015. <http://www.jstor.org/stable/3702081>.