Home > Aging, Causes of dementia, Depression, Psychological issues > More On Dementia and Depression

More On Dementia and Depression

Image courtesy graur razvan ionut @ http://www.freedigitalphotos.netI was very flattered at the attention that my last post, Dementia and Suicide, garnered.  I did some more digging on the subject of dementia and depression, and was somewhat surprised at what I found.  Not only are persons with dementia at risk for becoming depressed, the reverse is also true.  Apparently, older adults who have depression are also at significant risk for developing certain kinds of dementia, according to an article found on line at the NY Times.

It has long been recognized that persons with dementia are at risk for developing serious depression.  Many, when first diagnosed and still in the early stages, become depressed when considering what lies ahead for them and for their families — especially if the onset comes at an early age.  But other factors can contribute as well, including social isolation, side effects of medications, and concurrent health problems.  But recently, researchers have discovered that persons with clinical depression are at significant risk for the physical and biochemical changes in the brain that lead to both Alzheimer’s disease and vascular dementia.

On May 1, 2013, a report on this subject was published in the British Journal of Psychiatry.  It described the results of a meta-analysis of 23 previous studies involving almost 50,000 older adults (older than 50 years of age) for varying periods of time.  Scientists discovered that study participants were more than twice as likely to develop vascular dementia than people of similar ages who were not depressed.  They were 65% more likely to develop Alzheimer’s disease than the non-depressed population.

One of the paper’s co-authors, Meryl Butters, an associate professor of psychiatry at the University of Pittsburgh School of Medicine, stated that this report doesn’t go so far as to indicate that depression causes dementia.  But what it does suggest is that the disease processes and injuries that cause the depression may also contribute to those processes that can lead to dementia.

Dr. Butters suggested that, according to the study results, 36 out of 50 older adults with late-life depression may go on to develop vascular dementia, with 31 out of 50 may at some point be diagnosed as having Alzheimer’s.  The information that I read did not state whether these two groups are mutually exclusive of each other, or whether certain individuals may fall into both groups simultaneously.  This also doesn’t mean that a person who has late-life depression will automatically develop dementia.  Likewise, it doesn’t give any indication that preventing one condition will lead to a prevention of the other.

It has long been theorized that there is a causal relationship between depression and Alzheimer’s disease.  But relatively new and surprising is the suggestion that there may also be a similar connection between depression and the interruption of blood flow in the brain that can come with strokes and other types of injury, that can lead to vascular dementia.

There are some signs that point to a high level of the hormone cortisol that is produced by people with depression.  Cortisol has been related to the stress response as well as a smaller than average hippocampus in an individual’s brain.  (The hippocampus is a structure which has been associated with short-term memory and new learning.)  It has also been suggested that depression contributes to chronic inflammation and the inflammatory process, which can damage blood vessels and interfere with the flow of blood in the brain.

It has been suggested by some researchers that dementia and depression may share a genetic foundation.  It may also be that when a person begins to experience impaired thinking and difficulties with memory, they may unconsciously react emotionally in such a way that they become depressed.  It may also be that the mental effort of dealing with depression may sap the individual’s cognitive reserves to an extent that problems which are already existent, but less noticeable, are brought out into the open.

There are two conclusions that can be drawn from this information.  One is that there needs to be much more research done on the connection between depression and dementia, and any possible causal relationship that may be present.  The other is that we need to take note of the older person who becomes depressed, and take steps to treat this depression aggressively.  While this may or may not actually prevent the development of depression, it will undoubtedly improve the person’s quality of life.

It should be noted that one problem existed with each of the 23 studies included in the analysis.  In each case, study participants were asked to self-report symptoms of depression.  Too, there was no exclusion made for persons with Mild Cognitive Impairment, which has been seen by some as a possible precursor for dementia.  People with MCI have often been noted to have a high incidence of depression, so this may have skewed the results of the analysis to some extent.

However, since other studies in the past have pointed to a definite relationship between Alzheimer’s and depression, it may be presumed that other forms of dementia may also share in this.  A study completed last year by Dr. Deborah Barnes, associate professor of psychology, epidemiology, and biostatistics, at the University of California, San Francisco, indicated that older adults were three times more likely to develop vascular dementia if they also had depression starting in middle age.  This study was conducted through surveying 13,535 members of a  health maintenance organization in California, and was published in JAMA Psychiatry.


  1. July 9, 2013 at 2:25 PM

    Thank you for an informative blog and for guidance on where to find additional information. I’ve sustained 5 TBIs and am always looking for information regarding cognitive health. Additionally, my husband is bipolar and as a result of his receiving ECT in 2000 wherein he lost 55 years of his memory (http://sheridegrom.wordpress.com/2012/07/09/aftermath-of-memory-loss/) we are fearful he too might become a casuality of dementia. We are seeing related signs of unwated body movements, stiff limbs, inability to find certain words, etc.

    • July 9, 2013 at 2:41 PM

      You’re very welcome. It’s always nice to hear from my readers, and to know that my efforts have been helpful. I hope I can continue to provide useful information. And I also hope that you and your husband can find some peace, and some help in your struggles.

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