BackgroundPrevious studies suggest that offspring of mothers with psychotic disorders have an almost two-fold higher mortality risk from birth until early adulthood. We investigated predictors of mortality from late adolescence until middle age in offspring of mothers with psychotic disorders.MethodThe Helsinki High-Risk Study follows up offspring (n=337) of women treated for schizophrenia spectrum disorders in mental hospitals in Helsinki before 1975. Factors related to mortality up to 2005 among offspring of these mothers was investigated with a survival model. Hazard rate ratios (HRR) were calculated using sex, diagnosis of psychotic disorder, childhood socio-economic status, maternal diagnosis, and maternal suicide attempts and aggressive symptoms as explanatory variables. The effect of family was investigated by including a frailty term in the model. We also compared mortality between the high-risk group and the Finnish general population.ResultsWithin the high-risk group, females had lower all-cause mortality (HRR 0.43, p=0.05) and mortality from unnatural causes (HRR 0.24, p=0.03) than males. Having themselves been diagnosed with a psychotic disorder was associated with higher mortality from unnatural causes (HRR 4.76, p=0.01), while maternal suicide attempts were associated with higher suicide mortality (HRR 8.64, p=0.03). Mortality in the high-risk group was over two-fold higher (HRR 2.44, p<0.0001) than in the general population, and remained significantly higher when high-risk offspring who later developed psychotic disorders were excluded from the study sample (HRR 2.30, p<0.0001).ConclusionsOffspring of mothers with psychotic disorder are at increased risk of several adverse outcomes, including premature death.