Social contact reduces dementia risk in individuals with high neuroticism

Active social contact can reduce the increased risk of dementia associated with high neuroticism, according to a new study published in the Journal of Affective Disorders.

Neuroticism, a personality trait characterized by emotional instability and a heightened stress response, is associated with negative health outcomes, including dementia. Previous studies have shown that individuals with high neuroticism face an elevated risk of developing dementia. As the global population ages, with dementia prevalence expected to triple by 2050, identifying factors that can mitigate this risk has become increasingly important.

The World Health Organization’s 2022 dementia prevention guidelines acknowledge social contact as essential for cognitive health. In this work, Yufei Liu and colleagues investigated whether frequent social contact could lower the heightened dementia risk associated with neuroticism.

The researchers utilized data from the UK Biobank, a large-scale biomedical database. This included 393,939 participants aged between 37 and 73 years, with an average age of 56.4 years. Of these, 53.7% were female. Participants were initially recruited between 2006 and 2010, and data were collected through questionnaires, interviews, and health assessments. Neuroticism was assessed using the Revised Eysenck Personality Questionnaire, which included 12 questions designed to measure emotional instability.

Social contact was evaluated through three measures: household size (whether the participant lived alone or with others), frequency of contact with friends or family (ranging from daily to less frequent interactions), and participation in group activities (such as sports clubs, social groups, or religious organizations). The researchers divided participants into three groups: low, intermediate, and high social contact.

Dementia diagnoses were identified using participants’ electronic health records, which were linked to hospital admissions and death registries. Dementia was classified according to the International Classification of Diseases 10th revision (ICD-10), and specific types of dementia, such as Alzheimer’s disease and vascular dementia, were recorded. Participants were followed over an extended period, with follow-up continuing until December 2022.

The study considered a range of potential confounding factors, such as age, sex, education level, socioeconomic status, and lifestyle choices (e.g., smoking, alcohol consumption, physical activity). Participants’ genetic susceptibility to dementia, specifically the presence of the APOE ε4 allele, was also accounted for. Participants with incomplete neuroticism or social contact data, those diagnosed with dementia at the beginning of the study, or who withdrew from the study were excluded from the final analysis.

Over the study’s follow-up period, which had a median duration of 13.7 years, 6,588 cases of dementia were identified among the participants. Individuals with high neuroticism had a significantly higher risk of developing dementia compared to those with low neuroticism. Specifically, participants with high neuroticism had a 16% increased risk of all-cause dementia and similar elevated risks for Alzheimer’s disease (10%) and vascular dementia (16%).

Social contact played a protective role in mitigating dementia risk, particularly for individuals with high neuroticism. Participants with intermediate levels of social contact had a 15% lower risk of developing dementia compared to those with low social contact, and those with high levels of social contact experienced a 22% reduction in risk. Notably, among individuals with high neuroticism, those with high social contact had dementia risk levels comparable to individuals with low neuroticism.

One limitation is that the study only assessed social contact at baseline, and it is possible that social engagement levels may have changed during the follow-up period.

Overall, these findings suggest that promoting social engagement could be an effective strategy in dementia prevention, especially for those with a predisposition to neuroticism.

The research, “Neuroticism personality, social contact, and dementia risk: A prospective cohort study,” was authored by Yufei Liu, Jie Chang, Yiwei Zhao, and Yi Tang.