A META-ANALYSIS of longitudinal data from over 600,000 individuals reveals that loneliness significantly increases the risk of developing dementia and cognitive impairment. This finding highlights loneliness as a critical modifiable risk factor for cognitive health, with potential implications for prevention and intervention strategies in clinical practice.
The analysis combined data from ongoing aging studies and published literature to investigate the association between loneliness and dementia. This meta-analysis represents the largest of its kind, encompassing 21 samples (N = 608,561) for dementia and 16 samples (N = 103,387) for cognitive impairment. Hazard ratios (HRs) were calculated to assess the risk. Results showed that loneliness increased the risk of all-cause dementia by 30% (HR 1.306, 95% confidence interval (CI) 1.197–1.426), Alzheimer’s disease by 39% (HR 1.393, 95% CI 1.290–1.504), vascular dementia by 73% (HR 1.735, 95% CI 1.483–2.029), and cognitive impairment by 15% (HR 1.150, 95% CI 1.113–1.189). Importantly, these associations remained significant even when controlling for depression, social isolation, and other modifiable dementia risk factors. However, large heterogeneity was observed across studies, partially attributable to differences in how loneliness and cognitive impairment were measured.
The findings reinforce the need to address loneliness as a modifiable risk factor in clinical practice. Future research should explore specific types and sources of loneliness to inform targeted interventions aimed at reducing dementia risk. This could lead to the development of personalized treatment plans that include psychosocial support and mental health resources to mitigate the cognitive decline associated with loneliness. Given the growing aging population, understanding and addressing loneliness as a public health priority may have a profound impact on dementia prevention strategies.
Reference
Luchetti et al. A meta-analysis of loneliness and risk of dementia using longitudinal data from >600,000 individuals. NaT Mental Health. 2024;DOI:10.1038/s44220-024-00328-9.
