Attention-deficit/hyperactivity disorder (ADHD) may be associated with higher rates of mortality due to injury, according to research results published in JAMA Network Open. Few studies have assessed mortality rates in patients with ADHD, and their findings lacked data on specific causes of death.
To investigate the association between ADHD and causes of death, researchers in Taiwan conducted a nationwide population-based cohort study using data from a cross-national Taiwanese registry. The study included data from 275,980 patients aged 4 to 44 years who had been diagnosed with ADHD and 1,931,860 sex- and age-matched controls. The researchers collected data on mortality from suicide, unintentional injury, homicide, and natural causes from a national mortality database. The association was analyzed by a Cox regression model controlling for sex, age, residence, insurance premium, outpatient visits, congenital anomaly, intellectual disability, depression disorder, autism, substance use disorder, conduct disorder, and oppositional defiant disorder. A competing risk adjusted Cox regression analysis assessing cause of mortality controlled for other potential confounding factors.
After adjusting for potential confounders, the researchers found that compared with the non-ADHD group, patients in the ADHD group had a higher mortality rate (adjusted hazard ratio [HR], 1.07; 95% CI, 1.00-1.17) and higher injury-cause mortality from suicide (HR, 2.09; 95% CI, 1.62-2.71), unintentional injury (HR, 1.30; 95% CI, 1.10-1.52), and homicide (HR, 2.00; 95%CI, 1.09-3.68). The researchers found no increased risk for mortality from natural causes. The absolute risk for mortality was low despite the increased risk for injury mortality in patients with ADHD.
The study was limited by its reliance on healthcare data rather than on structured clinical interviews. In addition, the data are limited to Taiwan, which may affect the generalizability of the findings. The researchers also did not analyze the effects of ADHD medications, family history, or psychosocial stress.
“It is imperative to explore the underlying mechanisms of injury deaths in patients with ADHD to help develop effective prevention methods,” researchers concluded.
Chen VC, Chan H, Wu S, et al. Attention-deficit/hyperactivity disorder and mortality risk in Taiwan. JAMA Netw Open. 2019;2(8):e198714.