Evidence

Trials and surveys of group identification and community belonging: a group-identification program reduced loneliness more than usual care, with stronger belonging to multiple groups (Haslam 2019), and community identification is reported to relate to well-being through social support and reduced loneliness (McNamara 2021).

Social-connection studies in populations beyond older adults: multicomponent programs for caregivers reported effects on burden, depression, health and social support (Abrahams 2018); peer support reduced depression and anxiety in perinatal mothers (Shah 2024); 80% of student interventions based on social support groups, social interaction or reflective exercises were effective for loneliness (Ellard 2022); loneliness and isolation were more prevalent among resettled refugees than population norms (Nguyen 2024); and effects differed by gender, culture and age (Shukla 2020; Blessin 2022; Michalski 2024).

Reviews report that digital programs can reduce loneliness under certain conditions, particularly with group or social components (Hansen 2025); that information and communication technology reduced depression and anxiety with limited effect on social isolation (Bermúdez Endrino 2025); that analogue, community-based programs tended to be more effective than technological ones (Bergsträsser 2026); that social prescribing has a positive influence on mental health and wellbeing (Dubbeldeman 2024) while robust conclusions cannot yet be made (Cooper 2022); and that time on social networking sites is only weakly related to well-being (Huang 2017).

Reviews of loneliness interventions differ: several meta-analyses report reduced loneliness (Yu 2023; Hansen 2025; Coppola 2025; Teoh 2021; Yang 2025), others report effects that were not statistically significant or were limited (Grillich 2023; Jarvis 2020; Coll-Planas 2016), and group-based, participatory and theory-based formats more often reported improved outcomes (Dickens 2011).

Quality of social contacts was more strongly associated with well-being in later life than quantity (Pinquart 2000); contact frequency showed a modest mortality association with null subgroups (Shor 2015); and larger network size a small protective association (Schutter 2022).

Social isolation and loneliness are associated with higher all-cause mortality across many meta-analyses (Nakou 2025; Naito 2023; Rico-Uribe 2018; Harris 2023) and with coronary heart disease and stroke (Valtorta 2016); lower social-contact frequency was associated with higher mortality, with moderate effect sizes and null subgroups (Shor 2015).

Social engagement and social activities are associated with lower risk of cognitive decline (Joshi 2023), and lack of social connection is described as a risk factor for dementia (DeAngelis 2026).

Having few social contacts (isolation) is objectively linked to higher risk of heart disease, stroke, and early death.

Loneliness, the gap between the connection you want and what you have, is linked to depression and worse mental health.