Causal relationship between sleep duration and attention deficit hyperactivity disorder：a two⁃sample Mendelian randomization study

Abstract

Objective To investigate the causal relationship between sleep duration and the risk of attention deficit hyperactivity disorder（ADHD）in children using Mendelian randomization（MR）. Methods Genome-wide association study（GWAS）datasets for sleep duration（ukb-b-4424）and ADHD（ieu-a-1183）were downloaded，and 48 single nucleotide polymorphisms（SNPs）were selected as instrumental variables（IVs）. The causal association between sleep duration and ADHD risk was assessed using inverse-variance weighted（IVW），weighted median estimator（WME）， MR-Egger regression，weighted mode，and simple mode methods，with odds ratio（OR）used to estimate the effect. Sensitivity analysis was conducted using the leave-one-out method，while horizontal pleiotropy was evaluated using the MR-Egger intercept test，and heterogeneity was assessed using a random-effects model.Results IVW analysis revealed a negative correlation between sleep duration and ADHD risk（ OR=0.597，95%CI：0.376-0.948，P=0.028）. Sensitivity analysis confirmed stable results，and the MR-Egger intercept test indicated no significant horizontal pleiotropy. The random-effects model showed no heterogeneity. Conclusion Increased sleep duration is associated with a reduced risk of ADHD