Objective: Research in animals has shown that exposure to stressors during pregnancy is associated with offspring behavioural disorders. We aimed to study the effect of in utero exposure to the Chernobyl disaster in 1986, and maternal anxiety presumably associated with that exposure, on behaviour disorder observed at age 14.
Method: Exposed (n = 232) and non-exposed Finnish twins (n = 572) were compared. A semi-structured interview was used to assess lifetime symptoms of depression, generalized anxiety disorder, attention deficit hyperactivity disorder, conduct disorder and oppositional defiant disorder symptoms.
Results: Adolescents who were exposed from the second trimester in pregnancy onwards, had a 2.32-fold risk (95% CI: 1.13–4.72) of having lifetime depression symptoms, an increased risk of fulfilling DSM-III-R criteria of a major depressive disorder (OR = 2.48, 95% CI: 1.06–5.7), and a 2.01-fold risk (95% CI: 1.14–3.52) of having attention deficit hyperactivity disorder symptoms.
Conclusion: Perturbations in fetal brain development during the second trimester may be associated with the increased prevalence of depressive and attention deficit hyperactivity disorder symptoms.