A new research study performed by NIDA shows that regular marijuana use may cause impairment in the reward centers of the brain, affecting the dopamine response that the brain has. Dopamine is a neurotransmitter which is involved in pleasure, and it is released by the brain in specific situations. The research study does not identify whether the regular marijuana use came first and caused the impairment of the reward centers in the brain or if the impairment lead to regular marijuana use because of low dopamine levels. If the dopamine production is low or the receptors for this chemical are less sensitive then the individual may engage in regular marijuana use in an attempt to compensate for any dopamine deficiency. It is like the old chicken and the egg argument, and science has not yet determined which condition causes the other.
There are a number of research study publications that show regular marijuana use has an impact on the reward centers in the brain, it is precisely for this reason that the drug is abused in the first place. Further research study is needed before a causative link can be confirmed, right now the results simply fuel even more questions that need to be answered. Some research studies have shown that individuals who engage in regular marijuana use are more inclined to have certain conditions, personality traits, and disorders. These can include irritability, stress sensitivity that is higher than average, depression, and anxiety. The author of the research study was Dr. Nora Volkow, who is also the Director of NIDA.