Evaluating the cognitive effects of interventions to reduce social isolation and loneliness in older adults: a systematic review.

Objectives: Social isolation and loneliness among older adults present serious public health challenges linked to increased dementia risk. This systematic review analyzes interventions addressing social isolation and loneliness in older adults and their cognitive effects to inform future dementia prevention programs.
Method: We systematically searched databases (PUBMED, PsycINFO, SCOPUS, EBSCO, and SAGE Journals) from February to May 2023 and updated from August to November 2023 using terms like social isolation, loneliness, intervention, and cognitive outcome. We included studies that assessed cognitive outcomes (such as global cognition or specific domains) and non-cognitive outcomes (including depression, well-being, and functionality). Study quality was assessed using Cochrane's RoB 2, ROBINS-I, and other appraisal tools, with results synthesized narratively.
Results: Nine studies (1025 participants) were included, with a high risk of bias in most randomized trials (except one) and a low-to-moderate risk in non-randomized studies. Six studies showed improved cognitive function post-intervention, five of which involved technology. Two studies demonstrated reduced loneliness and improved cognition.
Conclusion: Technological interventions promise to reduce social isolation and loneliness, positively impacting cognitive function. Despite this, these interventions did not directly impact social isolation, which requires future and larger studies to understand more in-depth the role of these approaches for individuals with social isolation. The interventions promoting social interactions could lead to higher social identification, well-being, and interest in life. Multidomain interventions, including technology, are effective. Limitations include study scarcity and heterogeneity, highlighting the need for more robust research on interventions to alleviate social isolation and loneliness and enhance cognitive function. Systematic Review Registration PROSPERO CRD42023460933.