CAMBRIDGE, United Kingdom — Marijuana users get a bad reputation for being lazy or generally unmotivated while they get high. However, a new study finds that may be just a myth. Researchers from the University of Cambridge say cannabis users don’t show any less motivation to do things than people who avoid the drug.
Interestingly, the study finds “stoners” are actually more likely to enjoy themselves during common situations, like seeing friends and family.
The results come as cannabis use continues to rise globally and legalization becomes more widespread. This is especially true for younger users, as a 2020 report by the National Institute on Drug Abuse found 28 percent of 15 to 16-year-olds had consumed marijuana within the previous year.
Researchers in the U.K. recruited 274 adolescent and adult cannabis users to examine whether the drug leads to higher levels of apathy and anhedonia — a loss of interest in or pleasure from receiving rewards. Each of these individuals reported using marijuana at least weekly over the past three months, with the average participant using marijuana four times a week. The team then matched this group with a collection of non-users of the same age and gender mix.
Participants completed questionnaires measuring anhedonia, asking each person to rate statements including “I would enjoy being with family or close friends.” Study authors also measured levels of apathy by asking each person how interested they were in learning new things or how motivated they were to finish a task.
Cannabis users get more joy out of life
Results reveal that cannabis users actually scored slightly higher on tests measuring anhedonia than non-users. Simply put, people who use marijuana seem more capable of enjoying themselves.
Moreover, the study found there was no difference in apathy scores between users and non-users. The team also found no visible link between the frequency of cannabis use and levels of apathy or anhedonia.
“We were surprised to see that there was really very little difference between cannabis users and non-users when it came to lack of motivation or lack of enjoyment, even among those who used cannabis every day. This is contrary to the stereotypical portrayal we see on TV and in movies,” says Martine Skumlien, a PhD candidate in Cambridge’s Department of Psychiatry, in a university release.
Overall, adolescents tended to score higher than adults in both anhedonia and apathy, regardless of whether they use marijuana or not.
“There’s been a lot of concern that cannabis use in adolescence might lead to worse outcomes than cannabis use during adulthood. But our study, one of the first to directly compare adolescents and adults who use cannabis, suggests that adolescents are no more vulnerable than adults to the harmful effects of cannabis on motivation, the experience of pleasure, or the brain’s response to reward,” adds Dr, Will Lawn from King’s College London.
“In fact, it seems cannabis may have no link – or at most only weak associations – with these outcomes in general. However, we need studies that look for these associations over a long period of time to confirm these findings.”
Lazy stoner perception ‘is in itself a lazy stereotype’
The team also conducted a behavioral experiment with half of the volunteers, assessing both physical effort and each person’s pleasure after receiving rewards.
Participants had the option to perform button-presses to win points, which they could exchange for candy to take home. The test had three difficulty settings, with the more difficult ones requiring the participants to press the buttons faster. The player could also choose to accept or reject the offer and receive points for the tasks they completed.
The group then had to estimate how much they wanted each available reward, including hearing their favorite song, one piece of chocolate, or a one-dollar coin. After receiving each reward, the group rated how much pleasure it gave them on a scale of “do not like at all” to “intensely like.”
Results showed no difference between marijuana users and non-users or between different age groups.
“We’re so used to seeing ‘lazy stoners’ on our screens that we don’t stop to ask whether they’re an accurate representation of cannabis users. Our work implies that this is in itself a lazy stereotype, and that people who use cannabis are no more likely to lack motivation or be lazier than people who don’t,” Skumlien says.
“Unfair assumptions can be stigmatizing and could get in the way of messages around harm reduction. We need to be honest and frank about what are and are not the harmful consequences of drug use.”
Brain scans show the same thing
Based on earlier studies of marijuana’s impact on the brain, the team then examined fMRI scans to see if brain activity changed while someone smoked marijuana. They focused on the ventral striatum, a key region in the brain’s reward system.
Those scans did not find any noticeable changes in this brain region, suggesting that marijuana use does not alter how people respond to rewards and pleasure.
“Our evidence indicates that cannabis use does not appear to have an effect on motivation for recreational users. The participants in our study included users who took cannabis on average four days a week and they were no more likely to lack motivation. However, we cannot rule out the possibility that greater use, as seen in some people with cannabis-use disorder, has an effect,” concludes Professor Barbara Sahakian from the Department of Psychiatry at the University of Cambridge.
“Until we have future research studies that follow adolescent users, starting from onset through to young adulthood, and which combine measures of motivation and brain imaging, we cannot determine for certain that regular cannabis use won’t negatively impact motivation and the developing brain.”
The results are published in the International Journal of Neuropsychopharmacology.
