Effective interventions to reduce loneliness in big cities

Purpose of reviewLoneliness is a state of distress or discomfort between the desired and experienced level of connectedness to others. These feelings may be particular salient in urban environments that seemingly offer more opportunities for social contact, highlighting the discrepancy. The topic of loneliness has received increased attention because of its negative impact on mental and physical health combined with concerns of increased loneliness due to lockdowns and social distancing regulations during the coronavirus disease 2019 pandemic. We provide a bibliometric and random-effects meta-analysis of clinical trials published since 2020 and available via PubMed.Recent findingsLoneliness interventions have predominantly focused on elderly in the community. Adolescents and young adults as a second group at risk have received much less attention. On average across 44 effect sizes studied in 38 trials, interventions show moderate levels of effectiveness but are characterized by high heterogeneity and trials are often underpowered and use low quality designs. Multidimensional interventions show promise for alleviating loneliness, but the intervention context needs greater attention.Scalable and effective interventions for the general population and at-risk groups of loneliness are still scarce. Some promising interventions have been trialled and merit further attention.