The association between social connectedness and euthanasia and assisted suicide and related constructs: systematic review

Euthanasia and assisted suicide (EAS) requests are common in countries where they are legal. Loneliness and social isolation are modifiable risk factors for mental illness and suicidal behaviour and are common in terminal illness. Our objective was to summarise available literature to clarify whether these and related measures of social connectedness might contribute to requests for EAS. We conducted a pre-registered (PROSPERO CRD42019160508) systematic review and narrative synthesis of quantitative literature investigating associations between social connectedness and a) requested/actual EAS, b) attitudes towards EAS, and c) a desire for hastened death (DHD) by searching six databases (PsycINFO, MEDLINE, EMBASE, Scopus, Web of Science, Google Scholar) from inception to November 2022, rating eligible peer-reviewed, empirical studies using the QATSO quality assessment tool. We identified 37 eligible studies that investigated associations with a) requested/actual EAS (n = 9), b) attitudes to EAS (n = 16), and c) DHD (n = 14), with limited overlap, including 17,359 participants. The majority (62