Mental Health Conditions among Children and Adolescents with Congenital Heart Disease: A Danish Population-Based Cohort Study

BACKGROUND: Despite the known mental health burden among children with congenital heart disease (CHD), the literature is constrained by a lack of comparison cohorts and population-based follow-up data. We examined the incidence of mental health conditions among children with CHD, relative to 3 comparison cohorts. METHODS: This population-based cohort study identified all children with CHD (<18 years of age; n=16 473) in Denmark from 1996 to 2017, through linkage of individual-level data across national registries. This allowed for complete follow-up of the population. Comparison cohorts included children from the general population (n=162 204), siblings of children with CHD (n=20 079), and children with non-CHD major congenital anomalies (n=47 799). Mental health conditions were identified using inpatient and outpatient hospital discharge codes, prescription data, and data on use of community-based psychology, psychiatry, and psychotherapy services. We computed cumulative incidence by 18 years of age, incidence rates, and adjusted hazard ratios (aHRs) using Cox regression. aHRs accounted for sex, year of CHD diagnosis, parental mental health, and socioeconomic status. All estimates were stratified by age, sex, and CHD complexity. RESULTS: The cumulative incidence of mental health conditions by 18 years of age in the CHD cohort was 35.1% (95% CI, 34.0%-36.1%), corresponding to aHRs of 1.64 (95% CI, 1.58-1.71), 1.41 (95% CI, 1.30-1.52), and 1.02 (95% CI, 0.98-1.07) compared with the general population, sibling, and major congenital anomaly cohorts, respectively. Mental health incidence rates showed prominent peaks in early childhood and adolescence. Males and children with severe or single-ventricle CHD demonstrated higher incidence rates of mental health conditions relative to females and children with mild or moderate CHD, respectively. Compared with the general population and sibling cohorts, incidence rates and aHRs in the CHD cohort were highest for severe stress reactions, attention deficit/hyperactivity disorder, intellectual disability, and autism spectrum disorder. Compared with children in the major congenital anomaly cohort, the aHRs were close to 1. CONCLUSIONS: More than one-third of children with CHD were diagnosed or treated for a mental health condition by 18 years of age. Mental health conditions began early in life and were most prominent among males and children with severe or single-ventricle heart disease.