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Researchers say it is not yet clear whether treating depression reduces the risk of dementia.
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A diagnosis of depression in adulthood may more than double the risk of developing dementia later in life, according to a new study.
of The study was published Monday in the journal JAMA Neurology, “The study used data from more than 1.4 million Danish citizens followed from 1977 to 2018,” said Dr. Holly Elser, an epidemiologist and neurology resident at the University of Pennsylvania and lead author of the study.
People were identified with or without a diagnosis of depression, according to the study, and followed over the years to see who developed dementia later in life. The researchers adjusted for factors such as education, income, cardiovascular disease, diabetes, substance use disorders, and bipolar disorder.
The large datasets and numerous analyzes used by the researchers made the findings strong and reliable, but the lack of information, such as genetic data, limits the study, said Dr Nathalie Merchant, associate professor in the Department of Psychiatry at University College London. Mr. Marchant was not involved in the study.
Depression in late adulthood is often thought of as an early symptom of dementia, and many studies have linked the two, Elser said. However, newer research shows an association between dementia risk and a diagnosis of depression, even in early life and middle age.
“Thus, our results provide strong evidence that not only is depression an early symptom of dementia, but that depression increases the risk of dementia,” she said.
Although the association between depression and dementia has been shown to be strong, there are still unanswered questions in this study.
“For example, depression and dementia, which develop early in the life course, may have common risk factors. Depression may increase dementia risk through changes in levels of key neurotransmitters. It is also possible that depression causes changes in health behaviors, resulting in an increased risk of dementia,” she added in an email.
“Future studies are clearly needed to examine potential mechanisms linking depression in early adulthood with later dementia onset,” said Elser.
Another part of the findings is the stronger association seen in men than in women, Marchant said.
“This is an interesting finding and I hope it will be studied further,” she added in an email. “This supports the idea that dementia risk factors for men and women should be considered separately on a daily basis, as different mechanisms may be involved.”
The double whammy of depression and dementia can be terrifying. You may ask, will treatment reduce the risk?
It’s not clear yet.
The latest study looked at antidepressant treatment within six months of diagnosis and found no difference in risk between treated and untreated groups, Elzer said.
He added that further research into whether medications and cognitive-behavioral therapy at different times and durations are effective in reducing risk will be important.
Preliminary results from other observational studies show that older people who participate in treatments that reduce symptoms of depression and anxiety also have a lower risk of future dementia, Merchant added.
However, because the study was observational, the researchers added that they could not determine whether the treatments reduced cases of dementia.
“Still, taking care of your mental health is definitely important to your well-being right now,” Merchant says.
Elzer agreed that treating depression should be a priority, regardless of the risk of dementia.
“Depression is so prevalent and carries enormous costs to individuals and societies that effective treatment of symptoms of depression should be a priority, regardless of whether the symptoms pose a risk for dementia later in life,” she said.
