Associations of asthma and psychiatric comorbidities on suicide mortality among community adolescents: A 20-year cohort study

Background: The role of psychiatric comorbidity as a confounder between asthma and subsequent suicide mortality in adolescents remained unclarified. Methods: This study used a 20-year community-based cohort in Taiwan. Adolescents aged 11 to 16 from 123 schools were classified into three subgroups: current asthma (symptoms present in the past year), previous asthma (history of asthma but no symptoms in the past year), and no asthma. The mortality and medical care utilizations until the end of follow-up in 2015 were obtained. Cox proportional hazard and competing risk models were performed. Different adjustment models that included covariates of demographic status, allergy, cigarette smoking, psychiatric diagnoses, alcohol or substance misuse, and attention deficit and hyperactivity disorders were compared. Results: During the follow-up, 285 out of 153,526 participants died from suicide. The crude hazard ratio for suicide was 1.95 (95 % CI=1.46∼2.60) in the current asthma subgroup and 2.01 (1.36∼2.97) in the previous asthma subgroup. The adjusted hazard ratios (aHR) attenuated to 1.67 (1.25∼2.24) and 1.72 (1.16∼2.54) respectively after further adjustment for all mental disorders, ADHD, substance, and alcohol use disorders. Conclusions: Our adjustment analyses stratified by different models highlight evidence of asthma as an independent risk factor that predicts suicide among adolescents. Depression and mental disorders were potential confounders and identifications of asthma and psychiatric disorders might help decrease suicide risk.