Does Depression Lead to Dementia?

Medical experts have suspected that depression and dementia may be linked, but until recently they have been unable to prove the correlation. A new study may have done just that. However, many experts are still skeptical and fear such a blanket statement linking the two together could be unwise.

The study published in the journal Neurology suggests that people who are depressed are two to three times more likely of developing some form of dementia, including Alzheimer’s disease. Dr. Jane Saczynski of the University of Massachusetts Medical School led the study. Dr. Saczynski and her team gathered information for this study over a 17 year period. 949 participants with an average age of 79 were used in the study.

The participants were evaluated for depression at the onset of the study. 125 of the study participants were classified as having some sort of depression. At the conclusion of the study, 164 of the participants had developed dementia, with 136 of those cases being Alzheimer’s disease. 22 percent of the participants with depression, developed dementia during the course of the study. 17 percent of those who did not have any depression, later developed dementia. Researchers factored in a number of other factors including age, gender, and whether the participant had a gene known to be associated with Alzheimer’s disease.

Dr. Sacynski suggests that depression may induce dementia because of swelling brain tissue that occurs while a person is depressed.  She also notes that a person’s lifestyle including diet and exercise can contribute to depression.