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Is Marijuana Addictive?
Well, yes. But it’s complicated.
The idea that pot is not addictive is widespread. A global survey of 55,000 cannabis users last year found that while 75% believe messages around the health risks of marijuana — from driving under the influence to forgetfulness, as well as harmful chemicals in the smoke — only 64% believe the fact that some people who try it become addicted. Yet health experts and scientists agree marijuana is addictive, though less so than, say, heroin. And as cannabis potency soars, some experts worry that the addictive potential is rising, especially for the under-25 set whose brains are still developing.
“Definitely, yes,” cannabis is addictive, says Ruben Baler, a health scientist at the science-policy branch of the National Institute on Drug Abuse (NIDA). “About 10% of people who use marijuana run the risk of addiction,” Baler says. “The risk goes up if you use it frequently.”
Furthermore, according to a NIDA statement, “data suggest that 30% of those who use marijuana may have some degree of ‘marijuana use disorder,’” a term recently rolled into the pot lexicon in an as yet confusing attempt to recognize a spectrum of use from relatively harmless to harmful, and to snuff out the stigma of addiction.
Your brain on pot
A brain-imaging study last year found the brain’s neural circuitry is altered in young adults with cannabis dependence, especially for those who start in adolescence. “People with heavy cannabis use had abnormally high connectivity in brain regions important for reward processing and habit formation,” wrote the researchers, led by Peter Manza at the National Institute on Alcohol Abuse and Alcoholism. The findings were detailed in the journal Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.
All human addictions point back to dopamine, a chemical that transmits information between the brain’s neurons. Dopamine regulates many functions, from attention and learning to motor skills and emotions. In particular, dopamine is largely responsible for the sense of pleasure, that human frailty behind many motivations and all addictions. But dopamine doesn’t act alone. There’s serotonin (another feel-good chemical), adrenaline, and others.
