Effects of Parental Mental Illness on Common Child Health Outcomes

Background: Serious mental illness (SMI), including major depression, bipolar disorder, and schizophrenia, in parents is a major public health concern. Parental mental illness can adversely affect the health and well-being of children. Prior studies have demonstrated associations between maternal depression and child physical health conditions, including infection and injury, which are leading causes of morbidity and mortality in young children worldwide. No prior studies conducted in Asia have investigated whether young children whose mothers or fathers have mental illness, especially serious mental illness, are at higher risk and injury and infection. Objectives: Our aim was to compare the incidence of injury or common infectious diseases among young Taiwanese children whose parents were and were not affected by serious mental illness. Methods: We used a retrospective cohort design and utilized data from several population-based databases in Taiwan, including the Maternal and Child Health Database, the Taiwan National Health Insurance Research Database, and birth and death certificate databases. To account for clustering of recurring outcomes within children and multiple children having the same parent, we employed generalized estimating equation Poisson models to estimate incidence rate ratios (IRR) of injury and common infectious disease occurring before age 5 among children exposed to parental SMI compared to unexposed children. We examined whether these associations were modified by parent socioeconomic status and age. We also assessed whether the associations differed by whether the mother or father or both parents were affected and by the timing of onset and type of SMI diagnosis. Results: We identified 1,999,322 singletons born in 2004-2014 who had data from both parents (91% of all singleton deliveries). A higher percentage of children with parental SMI (61%) had any childhood injury compared to children without parental SMI (54%). Parental SMI was associated with a 14% (IRR 1.14, 95% confidence interval [CI] 1.13-1.15) and 49% (IRR 1.49, 95% CI: 1.42-1.57) higher risk of childhood injury and injury hospitalization, respectively. Parental SMI was also associated with a 4% (IRR 1.04, 95% CI: 1.03-1.05) higher risk of antibiotic-treated common infectious disease and a 31% (IRR 1.31, 95% CI: 1.29-1.33) higher risk of common infectious disease requiring hospitalization. Associations between parental SMI and these child outcomes were stronger with increasing paternal or maternal age. Additionally, the risk of injury or common infectious disease requiring hospitalization was greater among children with two SMI-affected parents than among those with SMI-affected mothers, only. Children with only SMI-affected mothers were at higher risk relative to those with only SMI-affected fathers. Additionally, risks were greater for children with parents affected by schizophrenia or bipolar disorder than for those whose parents had major depressive disorder. In general, associations with most outcomes were similar regardless of whether parents’ SMI diagnoses pre-dated or occurred after the child’s birth. Conclusions: Our study of Taiwanese children found that parental SMI is associated with increased risk of childhood injury and of common infectious disease. These findings highlight the importance of effective treatment for parents with SMI. In addition, enhancing parenting skills, promoting home safety, and providing support for these vulnerable families, including crisis planning and mapping social and health care resources, may reduce morbidity risk in offspring during the preschool years.