Maternal stress during pregnancy has been associated with schizophrenia in some settings with evidence suggesting that male and female offspring might be affected differently.

In an outbreak of violence in 1941, at least 180 Jews died in Baghdad; rapes, beatings and property damage injured hundreds more in other towns. We questioned whether this stress might be reflected in any change in schizophrenia incidence in people born in 1941.

We studied admissions to psychiatric hospitals in 39,606 men and 41,208 women, parents of the population-based Jerusalem cohort. We used proportional hazards models to estimate relative incidence of schizophrenia in various groups, over time. Subjects were followed from age in 1950 or immigration, till age at first hospital admission, death or 2004. Schizophrenia was defined by discharge diagnosis, ICD-10 = F20–F29 at any hospital event. Models controlled for secular and cyclic time trends.

For all years combined, the 3,679 male immigrants from Iraq showed a schizophrenia incidence similar to other men (relative risk RR = 0.92, 95% confidence limits 0.67–1.26). But for 141 men born in Iraq in 1941, RR = 4.12 (1.67–10.2, p = .0021 based on 6 cases), compared with men from Iraq born in all other years. Among other men, RR for 1941 births was 1.21 (0.78–1.88,). Women from Iraq showed no significant findings.

These findings enlarge on long-term consequences of ethnic violence. They raise intriguing questions about the relative resilience of the sexes, but should be interpreted cautiously, given that all subjects in this cohort had been able to reproduce.