CYP1A1 and attention deficit-hyperactivity disorder: When analyzed at a cluster level, a one-unit increase (%) in the DNA methylation of CYP1A1 cluster 2 (OR, 0.31; 95% CI 0.19–0.49), ESR1 cluster 1 (OR, 0.91; 95% CI 0.89–0.94), and MYO1G clusters 1 and 3 (OR, 0.97; 95% CI 0.96–0.99 and OR, 0.95; 95% CI 0.93–0.97, respectively) was associated with significantly lower odds of ADHD symptoms.