Substance use disorders among refugee and non-refugee immigrants in Sweden

Evidence is inconclusive on whether immigrants are at higher risk of substance use disorders compared to non-immigrants. We investigated the risk of drug and alcohol use disorder (DUD and AUD) in first- and second-generation immigrants with refugee and non-refugee backgrounds using the nationwide Swedish longitudinal healthcare and legal registers. We included 798 141 males and 756 903 females who turned 16 years of age between 2005 and 2020. DUD and AUD were identified between ages 16 and 25 years using healthcare and legal registers. Immigrants were categorized into first- and second-generation refugees and non-refugees. Cox proportional hazard models estimated DUD and AUD risk in relation to immigrant status (non-immigrants as reference), adjusting for covariates. Sensitivity analyses were conducted using healthcare register data only. DUD risks were higher among most refugee and non-refugee immigrants compared to non-immigrants, i.e. hazard ratios (HRs) ranged from HR: 1.05, 95% CI: 0.95-1.15 (first-generation female refugees) to HR: 2.63, 95% CI: 2.54-2.73 (first-generation male refugees). AUD risks among immigrants were lower or similar to non-immigrants, i.e. HRs ranged from HR: 0.55, 95% CI: 0.49-0.62 (first-generation female refugees) to HR: 1.17, 95% CI: 1.03-1.34 (first-generation male non-refugees). Sensitivity analyses restricted to healthcare registers yielded somewhat attenuated associations for DUD, particularly among first-generation male refugees. Refugee and non-refugee immigrants in Sweden were generally at elevated risk of DUD, whereas AUD risks were largely similar to or lower than that of non-immigrants. The findings were broadly robust in analyses restricted to healthcare data.