New research once again destroys the lazy stoner stereotype, or the cannabis amotivational syndrome theory, instead showing both teen and adult cannabis consumers are “no less likely” to be motivated, nor are they less likely to show interest in rewards.

”Cannabis amotivational syndrome” is a hypothesis tossed around from commentators in the media for years that suggests regular cannabis use can lead to apathy, or less motivation, and anhedonia, or loss of interest in pleasure from rewards.

This is part of the hype surrounding teens using cannabis in their developmental years. Paul Armentano, NORML Deputy Director wrote this for Chronic News about “the media’s absurd hysteria about teens and pot” adding that claims such as amotivational syndrome are often invented or grossly exaggerated.

But this new study examined both apathy and anhedonia levels, measured against controls to determine if stoners are truly less motivated—in the way they are often portrayed in the media.

This study was published in The August 24, 2005. International Journal of Neuropsychopharmacology.

A team led by scientists at University College London (UCL), the University of Cambridge, and the Institute of Psychiatry, Psychology & Neuroscience at King’s College London examined whether cannabis users show higher levels of apathy and anhedonia versus controls and whether they were less willing to exert physical effort to receive a reward.

CannTEEN is also studying other aspects of teen cannabis use. To conduct the research, we selected 274 adult and teenage participants who had consumed cannabis at least one week.

“Our results suggest that cannabis use at a frequency of three to four days per week is Not associated with apathy, effort-based decision-making for reward, reward wanting, or reward liking in adults or adolescents,” the researchers concluded, however finding lower anhedonia in users, but with a “small effect size.”

Martine Skumlien is a doctoral candidate at the University of Cambridge’s Department of Psychiatry. She immediately noticed the absurd claims made about cannabis in media.

“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 said. “This is contrary to the stereotypical portrayal we see on TV and in movies.”

“There’s been a lot of concern that cannabis use in adolescence might lead to worse outcomes than cannabis use during adulthood,” Dr Will Lawn of the Institute of Psychiatry, Psychology and Neuroscience at King’s College London said. “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.”

“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.”

The study involved more than half of the participants. There were two tasks that assessed their physical effort. In order to earn points which could later be used to buy chocolates or sweets, the participants had to click a button. Three difficulty levels were available, with three reward levels. More difficult tests required more button pressing. Each test offered the possibility for the participant to reject or accept the offer. Points were awarded only if they are completed.

Another task measured the pleasure users received from reward rewards. The researchers found “no difference between users and non-users or between age groups on either the physical effort task or the real reward pleasure task, confirming evidence from other studies that found no, or very little, difference.”

Another recent study also dismissed the marijuana amotivational theory.

A previous study, “Effort-related decision making and cannabis use among college students,” published January 27 in Experimental and clinical psychopharmacologyThe theory of cannabis-induced motivational syndrome is also rejected by, who found no support for it.