Depression in midlife and late life is associated with an increased risk for developing Alzheimer’s disease and/or vascular dementia. The most recent study was completed on 13,535 members of Kaiser Permanente (a not-for-profit health plan with its home in Oakland, CA) and published in the Archives of General Psychiatry (2012, 69, 493-498).

The design of the study was retrospective and included any member who had a medical diagnosis of depression or neurological based diagnosis of Alzheimer’s disease or vascular dementia. Records were reviewed from 1964 to 1973 (midlife) and 1994 to 2000 (late life). Depressive symptoms were reported in about 14% of those in midlife and about 9% of those with depressive symptoms in late life.

Those who were depressed at midlife had a 20% increased risk of dementia (either Alzheimer’s disease or vascular dementia). Those who were depressed in late life had a 70% greater risk and those with depression in both mid-and late life had an 80% increased risk. Overall 1,020 members were diagnosed with dementia (about 14%) with an average age of about 81 at follow up.

These results may reflect either that depression in mid and late life is causal in development of dementia or is an early symptom of dementia. This distinction is very important from a treatment perspective. If depression is causal, then treatment should focus on depression (psychotherapy and/or antidepressants). The assumption is that successful treatment would reduce the risk of developing dementia. This, of course, can only be resolved by conducting an adequate randomized clinical trial of treatments for depression. On the other hand, if depression is an early symptom of dementia, then treatment strategies should focus on cognitive/lifestyle therapy and proactive planning.

In any event, those who develop mid-or late life depression should be carefully evaluated and followed not only for mood but also for cognitive function by neuropsychological assessment. Screenings are too insensitive. A baseline measure of memory function should be determined and there should be comparative follow up assessments to allow appropriate treatment planning.

If you or someone you care about shows depression in middle or late life, ask for a complete evaluation of both memory as well as depression. The following signs suggest a need for such an assessment:

1. Easily lose patience
2. Easily to anger
3. Loss of energy
4. Loss of or too much sleep
5. Appetite changes
6. Sexual changes
7. Find no joy in any aspect of your life
8. Frequent crying spells
9. Feel a constant sense of depression, anguish, and despair
10. Don’t think you can go on much longer.
11. Wish for relief by death