Higher concentration of ATO induced higher Bmal1 expression levels (F = 5.160, p = 0.028) in HDF cultures from ADHD participants with moderate evening chronotype, particularly at ZT12 after synchronization (Bonferroni post hoc test, p = 0.041) compared to the participants with definite evening type. Here, BMAL1 is linked to attention deficit-hyperactivity disorder.