Parental Mental Disorders and Ages of Onset of Severe Mental Disorders in Offspring: A Nationwide Family-link Study

Abstract

Objective Few studies have investigated the association between age of onset of severe mental disorders (SMDs) in offspring and the likelihood of diagnoses of parental mental disorder. Method We enrolled 212,333 patients with schizophrenia, bipolar disorder (BD), or major depressive disorder (MDD) and 2,123,329 controls matched for age, sex, and demographics from the National Health Insurance Database of Taiwan. Poisson regression models were used to examine the likelihood of diagnoses of five mental disorders in their parents compared to the parents of the controls (reported as odds ratio (OR) with 95% confidence interval), including schizophrenia, BD, MDD, alcohol use disorder (AUD), and substance use disorder (SUD). The study cohort was classified into child-onset, adolescent-onset, and adult-onset groups according to the onset of SMDs in the offspring. Result The parents of patients with child-, adolescent-, and adult-onset schizophrenia (OR range: 1.73–9.08, all p < 0.05) or BD (OR range: 1.97–8.17, all p < 0.05) were more likely to be diagnosed with schizophrenia, BD, MDD, AUD, and substance use disorder (SUD) than controls except for AUD in the child-onset group. However, the parents of patients with child-, adolescent-, and adult-onset depressive disorder were more likely to be diagnosed with schizophrenia, BD, MDD, AUD, and SUD (OR range: 1.82–4.76, all p < 0.05) than controls. Sub-analyses stratified by sex showed different patterns of associations between parental mental disorders and offspring mental disorders. Conclusion No matter when the SMD occurred during the developmental milestone, their parents had higher likelihood of being diagnosed with schizophrenia, BD, MDD, AUD, and SUD.