The Associations of Mental Disorders in Children With Parents’ Subsequent Mental Disorders: A Nationwide Cohort Study From Finland and Denmark

Background Intergenerational transmission of mental disorders has been well established, but it is unclear whether exposure to a child’s mental disorder increases parents’ subsequent risk of mental disorders. Aims We examined the association of mental disorders in children with their parents’ subsequent mental disorders. Methods In this population based-cohort study, we included all persons with children born in Finland or Denmark in 1990–2010. Information of mental disorder was acquired from national registers. The follow-up period began when the parent’s eldest child was 5 years old (for codes F10–F60 ICD-10) or 1 year old (for codes F70–F98 of the ICD-10) and ended on December 31 st , 2019, or when the parent received a mental disorder diagnosis, died, or emigrated from Finland or Denmark. The association of mental disorders in children with their parents’ subsequent mental disorders was examined using Cox proportional hazards models. Results The study cohort included 1 651 723 parents. In total, 248 328 women and 250 763 men had at least one child who was diagnosed with a mental disorder. The risk of a parent receiving a mental disorder diagnosis was higher among those who had a child with a mental disorder compared to those who did not. For both parents, the hazard ratios were greatest in the first six months after the child’s diagnosis (HR between 2.04-2.54), followed by a subtle decline in the risk (after two years, HR between 1.33-1.77). Conclusion Mental disorders in children were associated with a greater risk of subsequent mental disorders among their parents. Additional support is needed for parents whose children have been recently diagnosed with a mental disorder.