Does living alone increase my risk of developing dementia?

The question of whether living alone raises your risk of dementia is not settled. Some research suggests that living alone may be linked to early signs of cognitive decline, but a large study found no direct connection to dementia itself. However, living alone was associated with a higher chance of being placed in a nursing home. It is important to distinguish between living alone (an objective measure) and feeling lonely (a subjective feeling), as the latter may carry more risk.

What the research says

A 2024 study from the MEMENTO cohort in France followed 2,269 people with cognitive complaints for about 5 years. It found that living alone was not linked to a higher risk of developing dementia (HR = 0.88, 95% CI 0.67–1.16). However, those who lived alone were more likely to be institutionalized (placed in a nursing home) ¹. This suggests that living alone may not cause dementia, but it can affect how people manage the condition.

On the other hand, a 2021 study from the CABLE study in China looked at risk factors for subjective cognitive decline (SCD) — when a person feels their memory or thinking is getting worse, even if tests are normal. That study found that living alone was one of several factors linked to a higher chance of SCD (odds ratio 1.30 to 2.29) ⁹. This means living alone might be a risk factor for early, self-reported cognitive problems, even if it does not lead to a dementia diagnosis.

An integrative review of empty-nest older adults (people over 60 whose children have moved out) also found that social isolation — which often includes living alone — was linked to cognitive decline, along with depression and loneliness ⁶. So while the direct link to dementia is not clear, living alone may contribute to other health issues that affect the brain.

It is worth noting that other factors like high blood pressure variability, hearing loss, and certain medications have stronger evidence linking them to cognitive decline ⁵⁴⁸. The evidence on living alone is less consistent.

What to ask your doctor

• Given my living situation, what are my personal risk factors for cognitive decline?
• Should I be screened for depression or loneliness, which can affect brain health?
• Are there community programs or support groups that could help reduce social isolation?
• What other modifiable risk factors (like blood pressure, hearing, or exercise) should I focus on?
• How often should I have cognitive screening, and what signs should I watch for?