Mood and neurotic disorders among youth with prenatal substance exposure: A longitudinal register-based cohort study

Background Prenatal substance exposure is associated with mood and neurotic disorders but this association is complex and understudied. This study investigated the recorded use of specialised healthcare services for mood and neurotic disorders among youth with prenatal substance exposure in comparison with an unexposed matched cohort. Furthermore, the influence of adverse maternal characteristics and out-of-home care (OHC) is investigated. Methods This longitudinal register-based matched cohort study included 594 exposed and 1735 unexposed youth. Cox proportional hazard regression models were applied to study the first episode of mood and neurotic disorders in specialised healthcare from 13 years of age, and the influence of adverse maternal characteristics and OHC. Mediation analysis was applied to study the mediating effect of OHC on the association between prenatal substance exposure and the disorders. Results The exposed cohort had a two-fold higher likelihood of being treated at specialised healthcare for mood and neurotic disorders compared with the unexposed cohort (HR 2.34, 95% CI 1.86–2.95), but this difference was attenuated to non-significant levels (AHR 1.29, 95% CI 0.92–1.81) following adjustments with adverse maternal characteristics and OHC. OHC mediated 61% (95% CI 0.41–0.94) of the association between prenatal substance exposure and youth's mood and neurotic disorders. Limitations Register data likely include more severe cases of disorders, and as an observational study, causality cannot be assessed. Conclusion Mood and neurotic disorders are more common following prenatal exposure to substances and interlinked with significant adversities in the postnatal caregiving environment and OHC.