CNR2 and attention deficit-hyperactivity disorder: Potentially useful biomarkers relating to alterations in ECS components include expression of cannabinoid receptor genes (CNR1, CNR2), which encode the cannabinoid receptors (CB1R and CB2R).57–60 CNS alterations related to ECS in the cerebellum, basal ganglia and hippocampus affect both ASD and ADHD.57,61,62