Prenatal smoking exposure and psychiatric symptoms in adolescence

Aim: Explore associations between smoking in pregnancy and psychiatric symptoms in the adolescent offspring. Design/subjects: A prospective population based follow-up of 84 adolescents at 14 years of age, of whom 32 of the mothers reported smoking during pregnancy. Main outcome measures: The Achenbach System of Empirically Based Assessment (ASEBA), ADHD-Rating Scale IV, Autism Spectrum Screening Questionnaire (ASSQ), Children's Global Assessment Scale (CGAS), estimated IQ based on four subscales of WISC-III. Results: Adolescents who were born by smokers had significantly more rule-breaking and aggressive behaviour, externalizing and total problems on the ASEBA than adolescents of non-smokers (p < 0.01), when reported by mothers, fathers and teachers. ADHD symptoms were reported more frequently (p < 0.05), and mothers also reported more internalizing symptoms (p < 0.05) and social problems (p < 0.001). The ASSQ sum score was higher (p < 0.001), and overall function as measured by the CGAS was lower (p < 0.01) for the smoking-exposed group. Associations were still present after controlling for possible confounding factors. Conclusion: Adolescents exposed to prenatal smoking had higher scores for both externalizing and internalizing psychiatric symptoms, which could not be explained by a broad range of possible psychosocial confounders. Thus, smoking in pregnancy may be a marker for increased risk of psychiatric symptoms in the offspring.