Smoking large amounts of marijuana during a period long can cause the opposite effect usually look for those who smoke, as a study just determined that this damages the pleasure center of the brain responsible for feelings of pleasure and reward.

Scientists know that drug abuse can wreak havoc on the dopamine system, a main ingredient in the brain’s reward system. People who abuse alcohol and cocaine, for example, produce much less dopamine in their brains than those who do not. Now, this study, conducted by the National Institute on Drug Abuse in Bethesda (USA) wanted to find out if the same effect occurs in those who smoke large amounts of marijuana.

To do this, they worked with metlfenidato, a stimulant that increases the amount of dopamine in the brain, which was distributed among 24 heavy smokers of marijuana (average of 5 joints a day, 5 days a week for 10 years) and 24 people in the control group.

Brain imaging revealed that both groups produced additional dopamine after taking the drug; but while the control group showed an increase in heart rate and readings of blood pressure and reported feeling restless, marijuana users did not, did not affect them. His answers were so weak that the researchers came to consider whether methylphenidate would be expired (it was not).

This lack of physical response suggests that people who abuse marijuana could have damaged the brain’s reward circuit. His brain, despite producing the same amount of dopamine that those who do not take drugs, your brain does not know what to do with it, producing a “disconnect”.