Purpose: There has been growing interest in understanding the economic impacts of loneliness and social isolation. This study updates a previous review on the economic costs of loneliness and social isolation and the cost effectiveness of related interventions.
Methods: We conducted a systematic search in the MEDLINE, PsycInfo, CINAHL, and Embase databases from 2018 to 13 August 2024, supplemented by a search of the grey literature. Studies included cost-of-illness studies, economic evaluations, and social return on investment (SROI) analyses published in the English language. All studies were evaluated for quality and summarised using a narrative approach. Costs reported were converted into US$, year 2024 values.
Results: In total, 15 studies were included: six cost-of-illness studies, four economic evaluations, and five SROI studies. Cost-of-illness studies primarily examined healthcare and productivity costs. All but one study reported excess costs linked to loneliness and social isolation, ranging from US$2 billion to US$25.2 billion per annum. Among four economic evaluations, three were model-based cost-utility or cost-effectiveness analyses (targeting older adults and the general population), and one was trial based (focusing on low-income individuals with health issues). One study found an intervention cost effective, whereas cost-effectiveness probabilities in others ranged from 54% to 68%. One study concluded that an intervention to reduce severe loneliness in older adults was cost effective but unlikely to be cost saving. All SROI studies reported positive returns, with SROI ratios ranging from US$2.28 to US$13.72.
Conclusion: This review highlights additional evidence on the economic burden of loneliness and social isolation. Future research should explore broader cost impacts beyond healthcare and expand cost-effectiveness studies to younger populations.
Loneliness is the feeling of being disconnected from others and wanting better social relationships. Social isolation means having few social contacts or relationships. Both are known to affect people’s health and wellbeing, but we do not yet fully understand how much they cost society or whether programmes that aim to reduce them are good value for money. This study updated a previous review done in 2020. We searched four major databases and other sources for studies published in the English language between 2018 and 2024. In total, 15 studies were included: six looked at the overall cost of loneliness and social isolation (called cost-of-illness studies), four assessed the value for money of specific programmes (economic evaluations), and five examined the social and economic benefits of programmes (called ‘social return on investment’ studies). Cost-of-illness studies found that loneliness and social isolation led to extra costs, mostly related to healthcare and lost work productivity, ranging from US$2 billion to US$25.2 billion per year. Of the four economic evaluations, one programme was cost effective, and others had a 54–68% chance of being worth the money. One programme for very lonely older adults was cost effective but unlikely to save money overall. All five studies of the social return on investment showed positive returns, with benefits ranging from US$2.28 to US$13.72 for every $1 spent. This review shows that loneliness and social isolation can be costly. Future research should include costs beyond healthcare and evaluate the cost effectiveness of programmes for a wider range of people, including younger people.
© 2025. The Author(s).