Depression and dementia risk: what we know (and why to treat it anyway)

I've had depression throughout my life and I've heard that depression increases the risk of dementia. Is that true? Does treating depression protect the brain?

The association between depression and dementia exists in studies — people with a history of depression have an increased risk. But the interpretation is more subtle than headlines suggest, and it's worth understanding.

A two-way link

Depression can contribute to the risk (due to chronic stress, isolation, and abandonment of healthy habits that accompany it) — but it can also be an early sign of dementia itself: brain changes that manifest as dementia decades later can begin by looking like depression. Observational studies cannot adequately separate these two interpretations, which is why science is cautious.

What the WHO says — frankly

For the specific purpose of reducing the risk of dementia, guidelines state that there is not yet enough evidence to recommend managing depression. But pay attention to the correct interpretation: this does not question the treatment of depression — the WHO itself maintains, in its general guidelines, that depression should be treated in all adults, with psychotherapy and/or antidepressants. What has not yet been proven is only the specific preventive effect on dementia.

What this means for you

Treat every depressive episode seriously, and not out of fear of dementia — for your present life, which is reason enough. Untreated depression robs years of quality of life, affects sleep, body, and relationships. If you feel signs of relapse (persistent sadness, loss of interest, changes in sleep and appetite), seek medical attention early — with your history, you are entitled to closer monitoring and to ask for help without waiting for it to "pass on its own".

The indirect bonus

There is a practical certainty: treated depression restores energy for everything else — moving, socialising, eating better, sleeping. And these are precisely the areas where the evidence for prevention is strongest. Taking care of mental health is, at the very least, what makes other preventions possible.