A large new study from Saint Louis University has found that older adults who have both depression and insomnia are at much higher risk of developing Alzheimer’s disease and other types of dementia.
The study looked at health records from nearly 2 million people and showed just how serious the connection is between mental health, sleep, and brain health.
The researchers found that people over 50 who had both depression and insomnia had a 91% higher chance of developing dementia compared to people without these conditions. People with depression alone had a 70% higher risk, while those with only insomnia had an 11% higher risk. The results were the same for people of different racial backgrounds.
This means that depression is a major risk factor on its own, but when combined with sleep problems, the danger becomes even greater. The study was published in the journal Aging & Mental Health and highlights the need for early treatment of both depression and insomnia to help prevent dementia later in life.
Dr. SangNam Ahn, the lead author of the study and an associate professor at Saint Louis University, said that mental health care should be a key part of dementia prevention—especially for older adults.
He explained that many people with depression and insomnia go without a diagnosis or treatment. By improving access to mental health services, we could help lower the number of people who develop Alzheimer’s disease in the future.
This research supports growing evidence that mental health and sleep are critical parts of brain health. Experts now urge doctors, health care workers, and policymakers to make sure older adults get the help they need for these common but often untreated conditions.
In summary, the study shows that taking care of your mental health and getting good sleep may not only improve your mood and quality of life—it might also protect your brain from dementia as you age.
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The study is published in Aging & Mental Health.
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