Does Smoking Pot Make You Dumb? Stoners Respond to Latest Research

For years, researchers have been producing studies about the effects of chronic marijuana use on our brains. Many say the drug is harmful in one way or another after long term, chronic use; others say it's neutral or even helpful.

Yet another study came out this week, funded by the National Institute for Drug Abuse and published in the Proceedings of the National Academy of Sciences. This study, which included 48 adult marijuana users, concluded that chronic pot users have a smaller orbitofrontal cortex—which is involved in the cognitive processing of decision-making and sometimes related to addiction. But, on the other hand, the test subject's brains showed increased connectivity, suggesting that they compensated for the loss of gray matter.

In other words, it's a wash. Lose some brain cells, gain connectivity in your brain to make up for it. Unfortunately, given the lack of consensus in the field, it still feels like we don't know if smoking pot makes you permanently dumb. So, I decided to do my own admittedly unscientific study: I simply asked a few aging pot smokers how marijuana has affected their brains.

"Nowadays, people tell me that they can't tell whether I'm stoned or straight," said San Francisco poet Phil Lumsden—who didn't sound baked over the phone. "Even my wife says so; there doesn't seem to be any difference between when you're ripped and when you're sober as a priest."

He told me that he's been getting high for the majority of his adult life. He lit up at work for years until the low-grade weed smuggled in from elsewhere was overtaken by California's potent bud. That stuff got Lumsden so stoned, he completely spaced out at the office.

As a result, Lumsden now tells me he sticks to a steady diet of after-work blazing. "I'm not sure whether it has become part of my personality, I really don't know. I don't sense too much of a difference. But now, even when I'm not stoned, that's still the way I perceive the world—as in when I'm stoned."

Emma (who spoke to me only if we used an alias), a college professor in Berkeley, recalled, like Lumsden, that today's marijuana is much more potent than the grass of the past. "The first time I smoked a joint was in a locked bathroom with the joint stuck in a toilet paper roll," she said. "You could take three or four puffs and not feel much."

Marijuana definitely has an effect on the way our brains work, she told me, and one that's pretty close to the Jeff Spicoli-esque stoner stereotype. In her experience, there's an aspect of weed that dampens the way people think. "It calms all the bullshit swirling around in my mind," she said. "Grass affects everyone differently—it makes some people paranoid—but the way it dampened [my mind] and mellows people, that part was appealing. But too much grass robs you of something, often ambition—that mellowing gone too far. And I saw it in a few cases."

Another long-time weed smoker, Andy, 55, an engineer with a PhD and 13 patents to his name, has been using marijuana since he was 15. (Andy agreed to speak if we used only his first name.)

Initially using pot to curb anxiety, he's continued to smoke for the past 40 years. "I don't think cannabis has really affected my brain's ability to function," he said to me on his way to a cancer research project he's working on at one of the universities in San Francisco. "Everyone talks about short term memory loss. I'm not sure about that. I think one thing that is true is [because of pot use] I don't seem to hang on to really bad memories the way other people do. Like my ex-wife does," he quipped. "That's why it's useful for people suffering from PTSD—it helps to disconnect the emotion attached to bad memories."

Anecdotally, after my brief and totally unscientific look at what aging pot users think, grass sounds like it has some effect on our brains and thinking. But like the research—the authors behind this paper admitted that their findings are in need of further study—it's not clear exactly what the causes or effects are. And while the scientists are busy running more experiments, a generation of stoners is going keep on puffing away.