Secondhand smoke exposure linked to odds of ADHD symptoms

(HealthDay)—Exposure to secondhand smoke (SHS) from pregnancy to childhood is associated with increased odds of having attention-deficit/hyperactivity disorder (ADHD) symptoms and subtypes, according to a study published online May 20 in JAMA Network Open.

Li-Zi Lin, Ph.D., from Sun Yat-sen University in Guangzhou, China, and colleagues examined the correlations of prenatal, early postnatal, or current SHS exposure with ADHD symptoms and subtypes in a cross-sectional study involving 48,612 children aged 6 to 18 years.

The researchers found that children who were ever exposed or always exposed to SHS from pregnancy to childhood had higher odds of having ADHD symptoms and subtypes compared with their unexposed counterparts (odds ratios ranged from 1.46 to 2.94; 1.50 for ever exposed and 2.88 for always exposed). The odds of having ADHD symptoms were increased for children with SHS exposure when exposed in the prenatal period, early postnatal period, or current period (odds ratios, 2.28, 1.47, and 1.20, respectively) compared with their unexposed counterparts. The odds of having ADHD symptoms and subtypes were increased for children whose fathers smoked 10 or more cigarettes/day on both weekdays and weekends compared with their unexposed counterparts (odds ratios ranged from 1.48 to 2.25).

"Our findings highlight the importance of strengthening public health efforts to reduce SHS exposure, which may reduce the health and economic burdens of individuals with ADHD," the authors write.