BACKGROUND Prenatal and perinatal factors have been linked to affective disorders. We therefore undertook an exploratory study to determine whether prenatal exposure to severe famine was associated with an increased risk of affective disorders.

METHOD Monthly birth cohorts that were exposed and unexposed to the Dutch Hunger Winter of 1944-45 were identified. The cumulative incidences of affective psychoses and neurotic depression (ICD-9 criteria) were compared between exposed and unexposed cohorts during each trimester of gestation.

RESULTS The relative risk (RR) of affective psychosis (broad and restricted definitions) among persons exposed to famine during the second trimester was significantly increased (broad: RR (95% confidence interval) = 1.62 (1.19, 2.20); restricted: 1.59 (1.14, 2.21)). Separate analysis by gender showed a significant association among males (broad: 2.26 (1.43, 3.57); restricted: 2.40 (1.49, 3.89), but not females (broad: 1.28 (0.84, 1.94); restricted: 1.17 (0.73, 1.76)). The risk of neurotic depression was not increased after prenatal famine exposure.

CONCLUSIONS These results suggest a possible relationship between prenatal famine during the second trimester and affective psychosis, lending plausibility to reports that have associated affective psychoses with prenatal exposures. Further studies of this relationship are warranted.