Affiliations: [a] Dementia Centre for Research Collaboration, School of Psychiatry, University of New South Wales, Sydney, Australia
| [b] Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia
| [c]
The University of Sydney, faculty of Health Sciences and Sydney Medical School Sydney, NSW, Australia
| [d]
Hebrew SeniorLife and Jean Mayer USDA Human Nutrition Center on Aging at Tufts University, Boston, MA, USA
| [e] Academic Department for Old Age Psychiatry, Prince of Wales Hospital, Randwick, Australia
Correspondence:
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Correspondence to: Dr. Henry Brodaty, Dementia Centre for Research Collaboration Sydney, AGSM Building, University of New South Wales, Sydney NSW 2052, Australia. E-mail: h.brodaty@unsw.edu.au.
Abstract: It has been reported that social engagement may be associated with dementia risk. We searched PubMed, EMBASE, PsycINFO, CINAHL, LILACS, Biomed Central, Scopus, and Web of Science from January 2012 – May 2017, supplemented by extraction from previous reviews. We included cohort and case-control studies examining the association between social engagement or loneliness and dementia risk, pooling data using a random-effects model. Registered: PROSPERO (CRD42017067074). We included 31 cohort and 2 case-control studies comprising 2,370,452 participants. Poor social engagement indices were associated with increased dementia risk, including having a poor social network (RR = 1.59, 95% CI 1.31–1.96; I2 = 0.00%) and poor social support (RR = 1.28, 95% CI 1.01–1.62; I2 = 55.51%). In long-term studies (≥10 years), good social engagement was modestly protective (RR = 0.88, 95% CI 0.80–0.96; I2 = 0.00%). Loneliness was non-significantly associated with increased risk (RR = 1.38, 95% CI 0.98–1.94; I2 = 45.32). Our findings encourage interventions targeting social isolation and disengagement for dementia prevention.
