Mental and physical health among first-generation and second-generation immigrants in Sweden

Abstract

Background: Migration implies profound psychosocial and socioeconomic changes. Previous studies demonstrate an increased risk of poor health, including mental disorders, among some immigrant groups. First- and second-generation immigrants in Sweden are about one fifth of the total population, which calls for further research on the association between country of birth and health in this large population group.

Objective: To examine whether second-generation immigrants have a higher risk of being hospitalized for mental disorders than the Swedish majority population after adjustment for socioeconomic status (study 1 ). To study whether the increased risk of being hospitalized for psychotic disorders among certain immigrant groups is present among second-generation immigrants and whether having one parent born in Sweden has a protective effect on this risk (study 2). To examine whether the increased risk of being hospitalized for alcohol and drug abuse among certain immigrant groups is present among second-generation immigrants and whether having one parent horn in Sweden has a protective effect on this risk (study 3). To examine the association between acculturation (age at migration), and self-rated health among young immigrants (study 4). To examine whether the increased risk of hospitalization for mental disorders that exists among some immigrant groups in Sweden persists in the next generation and whether it varies based on the sex of the second-generation immigrant or of the immigrant parent (study 5).

Methods: 1.9 million Swedish-born women and men aged 16-34 were followed from 1 January 1995 to 3 1 December 1998 for first hospital admissions for mental disorders, categorized in four main diagnosis groups. Second-generation immigrants were classed in four groups and the Swedish majority population used as reference group (study 1 ). In total 2.2 million individuals aged 20 39 years were followed from 1 January 1992 to 31 December 1999 for first hospital admission for schizophrenia and other psychoses (study 2) or alcohol abuse and drug abuse (study 3). Cox proportional hazard models were used to estimate hazard ratios (studies 1, 2 and 3). The random samples of 7,137 women and 7,415 men aged 16 34 years were obtained from the Swedish Annual Level of Living Survey during the period 1992-1999. Logistic regression was used to estimate odds ratios for self-rated health, after accounting for age, sex, father's socioeconomic status and social networks (study 4). All hospital diagnoses of mental disorders in first- and second-generation immigrants in Sweden between 1 January 1987 and 31 December 2001 were included. Standardized Incidence Ratios (SIRs) were used in the analysis (study 5).

Results: Second-generation immigrants with one parent born in Sweden and second-generation Finns had higher risks of being hospitalized for psychotic, affective, neurotic, and personality disorders than the Swedish majority population. All results remained significant after adjustment for socioeconomic status (study 1 ). The highest risks of psychotic disorders were found among first- and second-generation Finns, after adjustment for socioeconomic status. Having one parent born in Sweden had no protective effect on the risk of being hospitalized for psychotic disorders among second-generation immigrants (study 2). The highest risks of alcohol abuse and drug abuse were found among first- and second-gene ration Finns, after adjustment for socioeconomic status (study 3). The risk of poor self-rated health increased with increasing age at migratio to Sweden among first-generation immigrants (study 4). Several first-generation immigrant groups had increased risks of hospitalization for mental disorders. These risks persisted in some second-generation immigrant groups regardless of the sex of the second-generation immigrant or the immigrant parent or parents. Other second-generation immigrant groups evinced partial persistence of increased risk by sex or the appearance of new increased risk in the second generation (study 5).

Conclusions: The disabling symptoms of severe mental disorders, leading to hospitalization, call for increased awareness among clinicians and public health planners involved in the treatment and prevention of mental disorders, especially among certain immigrant groups. This awareness should also include alcohol and drug abuse. Immigrants who arrive in Sweden at higher ages might need special attention as they are more likely to suffer from poor selfrated health, a valid health status indicator that can be used in population health monitoring.