Marijuana Abusers Less Responsive to Dopamine

Marijuana Abusers Less Responsive to Dopamine

Marijuana Leaf, SEM – JA5445
With the legalization of marijuana becoming increasingly prevalent (but no less controversial) in states like Colorado and Washington, research pertaining to the drug’s chemical components and their long term effects on the human body remain scarce.  The challenge of studying the affects of marijuana can become quite difficult, as it involves approval from numerous federal agencies that become speed-bumps along the road to research.

However researchers from the National Institute on Drug Abuse in Bethesda, M.D., were able to take a closer look at brain imaging scans of marijuana abusers to see how the dopamine system (the brain’s “pleasure chemical”) was affected by excessive, long-term use of the drug.  Their findings showed that while both the control group and marijuana abusers produced similar levels of dopamine, marijuana abusers exhibited almost none of the physical responses such as increased blood pressure and heart rate, restlessness, or feeling high.

Cocaine and alcohol abuse has been known to cause a decrease in dopamine production in the brain, though the same cannot be said for marijuana.  This latest research suggests that marijuana abusers can still produce normal amounts of dopamine, but may experience less reward or pleasure from their normal activities, fueling further dependence on the drug that can damage the brain’s reward circuitry.

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