Approximately five percent of the Finnish population are Swedish-speaking and have higher socioeconomic position and longer life expectancy than the Finnish-speaking majority. Previous studies have not investigated whether Swedish-speaking Finns have lower risk of
schizophrenia spectrum disorders (
SSD) than Finnish-speaking Finns. We investigated this in a representative sample of 47 445 Finns born in 1972-1984. Hazard ratios of
SSD between language groups were assessed with conditional proportional hazards regression. Sex, parental ages at birth, paternal employment around conception, parental
psychosis and place and residence in the capital area were used as other explanatory variables. The prevalence of
SSD was 0.7% in the Swedish-speaking minority and 1.5% in the Finnish-speaking majority. In the adjusted regression model, belonging to the Swedish-speaking minority was associated with lower risk of
SSD (hazard ratio (HR) 0.41, 95% confidence interval (CI) 0.24-0.69). In a subset analysis by gender, the protective effect was evident among Swedish-speaking males (HR 0.32, 95% CI 0.15-0.68) but marginal in females (HR 0.75, 95% CI 0.41-1.37). Parental
psychosis and place of birth in the capital area were associated with higher risk of
SSD, whereas paternal employment at the time of conception was associated with lower risk of
SSD. Our results support the role of social factors in the etiology of
schizophrenia. Belonging to a minority with high socioeconomic status and social capital may be protective against
schizophrenia, especially for males.