According to several precedent studies, in the United States, there is a higher need for treatment against marijuana abuse, rather than treatment for heroin or cocaine abuse. However, until now, no viable drugs against marijuana abuse were discovered. Professor Robert Schwarcz, from the School of Medicine, at the University of Maryland, along with his research team, has discovered a new synthetic drug that decreases the effects of the main active ingredient in marijuana. The results of the paper were published earlier this week in the journal Nature Neuroscience.
The main psychoactive ingredient of marijuana is known as THC (tetrahydrocannabinol). It is responsible for producing the feeling of high and pleasure due to the fact that it increases the levels of dopamine inside the VTA (ventral tegmental area) and inside the nucleus accumbens. The VTA is an area located in the mesencephalon. The origins of all the dopaminergic neurons found in the mesocorticolimbic dopamine system are found within the VTA. The nucleus accumbens is found in the basal forebrain of each brain hemisphere. Precedent studies have linked the nucleus accumbens to emotional intelligence of pleasure, and the placebo effect.
The research team suggests that if individuals abusing marijuana would take a drug that is able to reduce dopamine activity in these regions of the brain, the euphoria effect of marijuana would be diminished, or even abolished. The synthetic drug tested by researchers is named Ro 61-8048. Its effect increases the levels of KYNA (kynurenic acid). The increased level of KYNA in both the VTA and nucleus accumbens is responsible for reducing the THC stimulation. The research team suggests that their results show that KYNA is able to block the dopamine receptors, thus reducing the euphoric effects of marijuana.
Laboratory tests were done on rats. Instead of THC, the researchers used a synthetic compound known as WIN 55,212-2, which has effects close to those of THC. The laboratory rats were taught how to press a lever and receive the synthetic compound. As a sign of addiction, the rats pressed the lever for WIN 55,212-2 rather often. However, after the new Ro 61-8048 drug was administered to a group of rats, the rats stopped pushing the lever as often as before. Researchers also tested if the new drug is able to prevent a relapse. Further results were also obtained by using the same drug on squirrel monkeys that were taking THC.
Professor Schwarcz and his research team, consisting of his colleagues and a group of researchers from the National Institute on Drug Abuse, concluded that further research is necessary before the FDA will approve the new drug for human use. Other studies have shown that higher levels of KYNA can cause cognitive damage, thus the new drug could prove to have more side effects than beneficial effects.
However, the individuals who support the legalization of marijuana use will advocate for the fact that marijuana addiction doesn’t necessarily need treatment.