Figure Molecular structure Molecular structure of delta-9-tetrahydrocannabiol (THC) (left), which has psychoactive properties, compared to molecular structure of cannabidiol (CBD) (right), which has little or no psychoactive effect. Molecular structure Molecular structure of delta-9-tetrahydrocannabiol (THC) (left), which has psychoactive properties, compared to molecular structure of cannabidiol (CBD) (right), which has little or no psychoactive effect. Terry D. Fife et al. Neurol Clin Pract 2015;5:344-351 © 2015 American Academy of Neurology