Does cannabis make you lazy?

Several approaches have been used to determine whether the cannabis affected the motivation of its users, with much the same conclusion each time. Repeated and continuous use of cannabis makes you lazy. Here's how it works.

Researchers at the University of British Columbia (UBC) gave THC, the psychoactive cannabinoid in cannabis, to rats. This made them less likely to perform complex tasks even for a large reward, with most favoring a small task despite a smaller bonus. The addition of CBD did not change the conclusion of the test.

Mason Silveira, who led the study, explains: «Perhaps unsurprisingly, we found that when we gave THC to these rats, they became fundamentally lazy. What was interesting, however, was that their ability to perform complex challenges was not affected by THC. The rats could still perform the task, they just didn't want to do it.»

Fucking rats. Now to the humans. A study the’University College of London (UCL) investigated the short-term effect of a single joint on motivation in humans. The researchers also tested the motivation of users who were addicted to cannabis but had not consumed during the test, and found that their level of motivation was no different from volunteers in the control group (non-consumers who had not used).

«Although cannabis is generally thought to reduce motivation, this is the first time a study has reliably tested and quantified this using an appropriate sample size and methodology,» says study author Dr Will Lawn. «It was also thought that long-time cannabis users might have problems with motivation even when they weren't high. However, when we compared cannabis-dependent people with the control group, both of whom had not used cannabis, we found no difference in motivation. This tentatively suggests that long-term cannabis use does not lead to residual motivational problems when people do not use cannabis. However, longitudinal studies are needed to provide more conclusive evidence.»

Researchers asked study participants to press a button repeatedly to earn money. Either 30 times in 7 seconds to earn 50 pennies, or 100 times in 21 seconds for rewards ranging from 80 pennies to £2. Cannabis users chose the difficult option in only 42% of cases, while the placebo group in 50% of cases.

Concerning the long-term effect of cannabis on motivation, a Californian study, based on a project by the University of Otago (New Zealand), followed 1,037 people from birth to the age of 38, and showed that people who smoked at least 4 days a week for many years ended up in a lower social class than their parents, with lower wages, fewer qualifications and less prestigious jobs than those who didn't use cannabis regularly. In the long term, very regular users experienced more financial, relational and work-related difficulties. One of the study's researchers concluded: «Cannabis may be better for your health than alcohol, but not for your finances».

These three studies tend to prove that a amotivational syndrome exists in heavy cannabis users. This syndrome has has been extensively documented between the 1960s and 1980s, among regular cannabis users (daily consumption in large quantities). Some think, however that this amotivational syndrome simply reveals a predisposition to depression or a reorientation of values, rather than a cannabis-induced pathology.