Dementia
A diagnosis of lasting cognitive decline severe enough to get in the way of daily life. Alzheimer's disease is the most common cause.
Studies count dementia from medical records, registries or a clinical assessment, usually as a first diagnosis during follow-up. Cognitive performance on this atlas is a test score that moves within healthy people. Dementia is the diagnosis. Its early stage can change behavior years before anyone names it, which matters for every observational link to it: a habit can look like a cause when it is an early symptom.
Also called all-cause dementia, incident dementia, major neurocognitive disorder.
Connected relationships
Meta-analysis · Moderate
Loneliness→Dementia
Higher loneliness increases dementia.
Most meta-analyses link loneliness to a higher risk of later dementia, with pooled risk ratios from 1.23 to 1.58. The largest single cohort, UK Biobank, found almost nothing once other factors were adjusted.
Cohort · Moderate
Social isolation→Dementia
Higher social isolation increases dementia.
In a large UK Biobank cohort, social isolation was linked to a 1.26-fold increased risk of dementia.
Sources
- L Qiao et al. (2022). Association between loneliness and dementia risk: A systematic review and meta-analysis of cohort studies.
- S Wang et al. (2023). Association between social integration and risk of dementia: A systematic review and meta-analysis of longitudinal studies.
- E Lara et al. (2020). Does loneliness contribute to mild cognitive impairment and dementia? A systematic review and meta-analysis of longitudinal studies.
- JS Kuiper et al. (2016). Social relationships and risk of dementia: A systematic review and meta-analysis of longitudinal cohort studies.
- C Lazzari et al. (2022). COVID-19, loneliness, social isolation and risk of dementia in older people: a systematic review and meta-analysis of the relevant literature.
- R Penninkilampi et al. (2019). The Association between Social Engagement, Loneliness, and Risk of Dementia: A Systematic Review and Meta-Analysis.
- C Shen et al. (2023). Associations of Social Isolation and Loneliness With Later Dementia.
- M Solmi et al. (2021). Factors Associated With Loneliness: An Umbrella Review Of Observational Studies.