Negative Social Interactions and Risk of Mild Cognitive Impairment in Old Age

Objective: To test the hypothesis that negative social interaction is associated with increased risk of mild cognitive impairment and rate of cognitive decline. Methods: Participants were 529 older people without cognitive impairment at study onset. They completed annual evaluations that included assessment of negative social interactions (e.g., unsympathetic behavior, rejection), cognitive testing, and clinical classification of mild cognitive impairment. Results: During a mean of 4.8 years of follow-up (SD = 2.5), 198 individuals (37.4%) developed mild cognitive impairment. In a proportional hazards model, higher baseline frequency of negative social interactions (M = 1.51, SD = 0.43, skewness = 1.60) was associated with higher risk of developing mild cognitive impairment (hazard ratio = 1.53, 95% confidence interval: 1.13, 2.07). Results were similar after adjustment for depressive symptoms, social network size, social activity, and loneliness. This association was mainly due to neglect and rejection. There was no change in negative social interaction rate over time (estimate = -0.003, SE = 0.004, p = .508). Higher baseline level of negative social interaction was associated with lower initial level of global cognition (estimate = -0.096, SE = 0.034, p = .005) but not with cognitive decline (estimate = -0.018, SE = 0.011, p = .098). A higher mean level of negative interactions across the study period was robustly related to faster cognitive decline (estimate = -0.036, SE = 0.012, p = .002). Conclusion: Frequent negative social interactions may be a risk factor for mild cognitive impairment and cognitive decline in old age.