Study: Cannabis Consumption Not Linked to Increased Apathy

A new study published in the International Journal of Neuropsychopharmacology on August 24 suggests that cannabis consumption is not associated with increased apathy, effort-based decision-making for reward, reward wanting, or reward liking in adults or adolescents. The small study also found that non-cannabis consumers had higher levels of anhedonia, or the inability to feel pleasure. 

The researchers from the University College London (UCL), the University of Cambridge, and King’s College London, used data from the CannTeen study, which included 274 adult (26- to 29-years-old) and adolescent (16-17) cannabis consumers who used cannabis one to seven days a week in the past three months. 

Participants completed questionnaires to measure anhedonia, asking them to rate statements such as “I would enjoy being with family or close friends.” They also completed questionnaires to measure their levels of apathy, which asked them to rate characteristics such as how interested they were in learning new things or how likely they were to see a job through to the end.

Cannabis users scored slightly lower than non-users on anhedonia – in other words, they appeared better able to enjoy themselves – but there was no significant difference when it came to apathy. The researchers also found no link between the frequency of cannabis use and either apathy or anhedonia in the people who used cannabis. 

Lead author and PhD candidate Martine Skumlien from UCL Psychology & Language Sciences and University of Cambridge, said the survey results were “contrary to the stereotypical portrayal we see on TV and in movies.” 

“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.” — Skumlien in a press release  

Co-author Dr. Will Lawn from UCL Psychology & Language Sciences and King’s College London, described the study as “one of the first to directly compare adolescents and adults who use cannabis,” and it “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.” 

“There’s been a lot of concern that cannabis use in adolescence might lead to worse outcomes than cannabis use during adulthood,” he said in a statement. “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.”

“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 said in a statement. “Unfair assumptions can be stigmatising 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.”