Involvement of the Endocannabinoid System in Drug Addiction - Elise Howard

Elise Howard

May 19, 2013

Blog Post #1

Involvement of the Endocannabinoid system in Drug Addiction

Drug addiction is characterized by actual physiologic changes in the brain which in turn leads to drug seeking behaviors even in the face of the many negative aspects that drug addiction is associated with. Not only do commonly abused drugs have reinforcing factors that make them easy to abuse, they also produce negative consequences that lead to potential relapse when going through withdrawal. It is important to note that there are reward pathways in the body that are some of the primary suspects concerning drug (and potentially other types) of addiction. The article by Maldonado, Valverde, and Berrendero (2006) looks into the potential of the endocannabinoid system (a reward system) and cannabinoid receptors (CB₁ and CB₂) as a route of drug addiction for multiple types of drugs; more specifically, CB₁ (Maldonado, Valverde, & Berrendero, 2006).

Studies using the selective CB₁ receptor antagonist rimonabant have shown that the CB₁ receptors do in fact play a large role in nicotine addiction which is promising for the future of possible tobacco addiction medications. In the case of alcohol addiction, the endocannabinoid system seems to play a role in addiction by regulating the rewarding effects to activating mesolimbic dopamine transmission. An interesting interaction exists between the endocannabinoid system and opioids; while the endocannabinoid system is crucial in the rewarding effects that opioids induce, it also plays a very important role in the physical dependence.  Psychostimulants work a little differently on the endocannabinoid system than the drugs mentioned before.  It works directly on the mesolimbic dopamingergic terminals. The article states that the endocannabinoid system does not contribute in the primary reinforcing effects of psychostimulants, but it is very important for preserving the drug seeking behavior (Maldonado, Valverde, & Berrendero, 2006).

                Overall, there needs to be more research into the mechanisms of the endocannabinoid system so that we can continue to make steps toward medications that can help with drug addiction as drug addiction is due to neurobiological changes in the brain, which may not necessarily be the predominant thought about the people who are addicted.  

Maldonado, R., Valverde, O., & Berrendero, F. (2006). Involvement of the endocannabinoid system in drug addiction. Trends in neurosciences, 29(4), 225–32. doi:10.1016/j.tins.2006.01.008