- Keith Humphreys
Attitudes toward marijuana have always been extreme. In people's minds, it's either just like any other hard drug that will get you hooked and completely ruin your life — as was the thinking for decades — or it's just no big deal, a substance with medicinal qualities that may do more good than bad.
With dozens of states legalizing cannabis for medical or recreational use, the population is starting to lean toward the latter way of thinking. A majority of Americans — about six in 10 — support legalization. Drive around the states where it is legalized, and you'll see giant billboards advertising pot. And often, they're selling the idea that weed is better and harder to become addicted to than other substances you might use on a daily basis, like alcohol or tobacco.
But has the pendulum swung too far that way? Is weed addiction a potentially serious problem?
Keith Humphreys, a professor of psychiatry and behavioral sciences at Stanford University, says people need to know the truth about marijuana. And the truth is likely somewhere in the middle of the debate over cannabis.
"If you want to say, 'Well, it's less addictive than heroin,' that seems to be true," Humphreys says.
It's not as addictive as other drugs, or even alcohol. But it's not harmless, either. About one in 10 cannabis users report having problems with it, such as trouble quitting, or problems with concentration, short-term memory or motivation.
And there are, in fact, withdrawal symptoms for regular users. Those include irritability, trouble sleeping, decreased appetite and anxiety, according to the National Institute on Drug Abuse. Advocates of the drug sometimes try to differentiate between "psychological" and "physical" addiction, but there isn't much of a difference, Humphreys says.
"From the point of view of neuroscientists, it's all physical," he says. "When people say it's in my mind, not my body, we say, 'the mind is a reflection of the body.'"
The number of people who regularly use marijuana and become dependent is small — around 9 percent, studies have shown, compared to about 15 percent for alcohol. And it can, in fact, cause cognitive issues that derail someone's life. Humphreys notes that those people might get mocked for being "stoners," but people don't realize they are battling addiction that can be tough on them.
Some populations are at greater risk of dependence than others. Generally, the later in life you start using cannabis, the harder it is to become addicted. A middle-aged person who starts using cannabis is very unlikely to become addicted. But a high-school kid who uses cannabis regularly? They're at a much greater risk.
"The reason why is the same reason why you can acquire a foreign language earlier: Brains are more plastic at a younger age," Humphreys says. ♦