A recent study has proven that heavy use of cannabis can lead to a compromised dopamine system. Decreased release was found in the striatum, which is the part of the brain that helps in paying attention and memory.

Earlier research has proven that drugs like cocaine and heroin have a major effect on the dopamine release in the brain. However, it is for the first time research proved similar effects on marijuana. Unfortunately, unlike heroin and cocaine, marijuana has been widely accepted in many parts of the world especially among the youth.

Anissa Abi-Dargham, M.D., of Columbia University Medical Center (CUMC), said that it's important to look into this issue because of widespread use of weed, especially among youngsters.

Decrease in an individual's dopamine level can result in many problems. First, it leads to an addiction. Deficient dopamine release can also result to Parkinson'a disease. Since dopamine is what controls the brain's pleasure centers, it can also affect an individual's emotional response to things. Heavy use of marijuana can change one's learning ability and behavior.

The study was done on a group of 11 adults aged 21 and 40 years old. All the 11 were matched with heavy controls. It was understood that the group started taking the drug at the age of 16 and became addicted to it by 20. They have been addicted to it since then for the past 20 years. Positron emission tomography (PET) was used by the researchers to scan and identify a radiotracing molecule that is connected to the brain's dopamine receptors.

The marijuana users stayed in the hospital for seven days during this study and did not use the drug. Through this way, the scanning did not measure the effects of the drug.