Living Alone and Dementia Incidence: A Clinical-Based Study in People With Mild Cognitive Impairment.

INTRODUCTION: Social isolation and living alone have been associated with negative outcomes, especially in the older population. We aim to investigate the effect of living alone on the development of dementia in people with mild cognitive impairment (MCI).

MATERIALS AND METHODS: In this longitudinal study, we enrolled 345 outpatients with MCI evaluated at baseline through a clinical and neuropsychological protocol. Data on living situation (living alone vs. living with someone) were also collected. The development of dementia at follow-up was the outcome of the study. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using Cox regression analyses. Laplace regression was used to model the time-to-dementia diagnosis as a function of living situation.

RESULTS: During the follow-up time (mean [SD]: 2.8 [2.2] years), 172 (50%) participants developed dementia. After controlling for age, sex, years of education, MCI subtype, presence of comorbidities, and antidepressant therapy, people with MCI living alone were more likely to develop dementia (HR: 1.5; 95% CI: 1.1-2.1), when compared to those living with someone. In addition, participants with MCI living alone were diagnosed with dementia 1 year earlier than those living with someone ( P = .012).

CONCLUSION: Living alone increases by 50% the risk of developing dementia and anticipates by 1 year the diagnosis in people with MCI. These results, in line with findings of previous population-based studies, emphasize the pivotal role of the living situation in identifying a frailer share of the population at higher risk of dementia to which devote ad hoc assessment and care.