Importance: Refugee children and adolescents are at increased risk of mental health difficulties, but little is known about how the characteristics of the neighborhood in which they resettle may affect vulnerability and resilience.

Objective: To test whether neighborhood socioeconomic disadvantage is associated with risk of psychiatric disorders among refugee children and adolescents and examine whether the association differs by sex, age at arrival, and family structure.

Design, Setting, and Participants: This quasi-experimental register-based cohort study included refugees in Denmark aged 0 to 16 years at the time of resettlement from 1986 to 1998. A refugee dispersal policy implemented during those years assigned housing to refugee families in neighborhoods with varying degrees of socioeconomic disadvantage in a quasi-random (ie, arbitrary) manner conditional on refugee characteristics observed by placement officers. Cox proportional hazard models were used to examine the association between neighborhood disadvantage and risk of psychiatric disorders, adjusting for relevant baseline covariates.

Exposures: A neighborhood disadvantage index combining information on levels of income, education, unemployment, and welfare assistance in the refugees' initial quasi-randomly assigned neighborhood.

Main Outcomes and Measures: First-time inpatient or outpatient diagnosis of a psychiatric disorder before age 30 years.

Results: Median (IQR) baseline age in the sample of 18 709 refugee children and adolescents was 7.9 (4.7-11.7) years; 8781 participants (46.9%) were female and 9928 (53.1%) were male. During a median (IQR) follow-up period of 16.1 (10.2-20.8) years, 1448 refugees (7.7%) were diagnosed with a psychiatric disorder (incidence rate, 51.2 per 10 000 person-years). An increase of 1 SD in neighborhood disadvantage was associated with an 11% increase in the hazard of a psychiatric disorders (hazard ratio [HR], 1.11; 95% CI, 1.03-1.21). This association did not differ between male and female individuals, refugees who arrived at different ages, or those from single- vs dual-parent households. In secondary analyses using prescribed psychiatric medication as the outcome, a similar association with neighborhood disadvantage was found (HR, 1.08; 95% CI, 1.03-1.14).

Conclusions and Relevance: In this cohort study, neighborhood disadvantage was associated with an increase in risk of psychiatric disorders. The results suggest that placement of refugee families in advantaged neighborhoods and efforts to enhance the neighborhood context in disadvantaged areas may improve mental health among refugee children and adolescents.