Depressed Adults Have Higher Chances of Experiencing Dementia
A study conducted in the University of Amsterdam was recently done on 2,000 Medicare recipients and showed that people who experience depression late in life are known to have higher chances of experiencing mild cognitive impairment and dementia later on. The patients who suffered from depression and experienced memory problems in the beginning of the study were even more likely to develop dementia.
Previous studies have already linked depression with dementia in older adults, as well as with Alzheimer's disease. However, no studies have yet figured out whether depression became a risk factor or an early symptom for dementia. This new study hoped to find out if depression in younger adults would precede a decline in memory in any way.
Was depression really causal or merely a reaction to impairment in the brain? Were these changes inside the brain causing cognitive decline and depression at the exact same time, perhaps?
To properly clarify the overall timing of memory loss onset and depression, the researchers' life-course study first took a look at the actual incidence of depression appearing in mid-life. More than 13,000 people between 40 and 55 years old were studied for this. These people were part of Northern California's Kaiser Permanente Medical Care Program and also took part in a health test from 1964 to 1973 known as the Multiphasic Health Checkup.
As a part of this test, the participants were asked to answer detailed questions regarding their medical histories and health behaviors. Their blood pressure levels, height and weight were recorded, too. Based on this self-reported data, researchers were then able to find out whether these people were suffering from depression or not. After that, the researchers looked at these people from 1994 to 2000 yet again to find out if they were depressed then. A few years later, from 2003 to 2009, when most of these people were in their 80s, the researchers did another follow-up to find out if they were experiencing Alzheimer's disease or dementia.
This study showed that 14.1% of the participants only had midlife depression; 9.2% of the participants only experienced depression later in life; and 4.2% of the participants were depressed in both of these stages of life. During the last follow-up, 2.5% of the participants had dementia; 5.5% of the participants had Alzheimer's disease; and 2.3% of the participants had vascular dementia, which is a kind of dementia that comes about from brain damage caused by impaired blood flow into the brain.
Overall, when compared with other people who never experienced depression at all, people with depressive symptoms during their mid-years of life, but not later on in life, were around 20% more likely to experience dementia later on in life. The people were experienced depression later on in life, on the other hand, had things even worse because they were known to be 70% more likely to experience dementia compared to their non-depressed counterparts.
Aside from that, the people who experienced depression later on in life were two times more likely to experience Alzheimer's disease compared to the people who didn't have depression. Conversely, the people who experienced both mid-life and late-life depression had at least three times more of a risk to experience vascular dementia.
Since the study was more observational than anything else, it couldn't really firmly establish any causal associations. However, its findings do seem to suggest that depressive symptoms precede vascular dementia. In fact, the people that were depressed in their mid-years and late-years of age had more risks of developing vascular dementia, where their depression might have been a real causal risk factor.
It is possible for those vascular changes inside the brain that play a part in depression - most of all in people who suffer from chronic depression - might increase their risk for dementia later on. These current vascular issues were also most likely the reason why they were more at risk for vascular depression overall.
Now, when it comes to the connection with Alzheimer's disease, depression seems to be more of an early symptom than anything else - a part of the whole neurodegenerative process that results in memory loss. The brain has neurons in it that get influenced during this time and they could handle cognitive functions and memory. However, there are some neurons that could be related to the changes in a person's mood, too.
Overall, the researchers say that they need to do more research if they want to confirm these findings, though, and they do admit that their study still has several weaknesses to it. For starters, mid-life depression was merely assessed through one question on their questionnaire. The diagnoses for dementia were also based on nothing but the medical histories and reported symptoms on the same questionnaire and didn't even involve any spinal fluid tests or brain imaging. A depression history before reaching each participant's mid-life years wasn't taken into account, either, nor was the influence of genes in Alzheimer's disease.
Still, the researchers are very hopeful that more research will be done in the true to explore these unanswered questions. Most importantly, they are hopeful that they will eventually be able to determine if treating depression during a person's mid-life can help prevent dementia later on. Without a doubt, this area of depression can be very hard to figure out because it would be hard to get comparisons due to the fact that it isn't ethical to leave somebody untreated if they report depression.
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Philbert Manalo is an SEO expert and article writer working for different companies and websites.
One of the sites he is currently working for is http://www.redorbit.com that focuses on science and space. It also includes some videos like violence in video games and health issue like Dementia.