Neurotoxicity of Exogenous Cannabinoids

The endogenous cannabinoid system regulates diverse aspects of physiological functions via specific cannabinoid receptors (CB) expressed in the brain and periphery. CB1 receptors mediate various neurological processes, whereas CB2 receptors mainly regulate immune responses and are involved in development of drug addiction and neuroinflammation. The cannabinoids are a heterogeneous group of endo-, phyto-, and synthetic cannabinoids. Cannabis and its products have been used for millennia, and these remain the most frequently used substances around the world. ?9-Tetrahydrocannabinol (?9-THC), the main psychoactive constituent of cannabis, produces psychotic-like symptoms. Acute and chronic cannabis use may impair learning and memory, attention, and psychomotor functions; however, studies on the life-lasting effects of cannabis on brain structure are ambiguous. During the last decade, a worrying trend has been observed regarding the increasing popularity of more potent, addictive, and harmful synthetic cannabinoids (SCs). Unlike ?9-THC, SCs use may lead to severe adverse effects including seizures, agitation, aggression, violence, anxiety, and panic attacks. Acute intoxication may be life-threatening or lead to persistent impairments in emotional and cognitive processing as a result of irreversible brain damage. This chapter describes the current state of knowledge regarding various aspects of the neurotoxicity of exogenous cannabinoids, including the harmful effects of their use during pregnancy.