A study published in Psychopharmacology and prepared by a team from the University College of London (UCL) discovered a link between the use of cannabis and the willingness to work for money. The Biotechnology and Biological Sciences Research Council funded the study to provide more tools to the psychopharmacologic field.
The research demonstrated that the plant’s THC has effects on motivation, but not exactly in the terms it has been proposed before. Cannabis is commonly thought to reduce motivation, and in most cultural and social thinking, frequent users of marijuana are more likely to have problems with their willingness to do something, not only when they are using the substance but even when they are not under the effects of it.
However, this study proved that there is a short-term effect between cannabis and the motivation in the subject, a frequent user of the substance turned out to be equally affected as those that are not marijuana addicts.
The mechanisms of motivation
The research used activities that took a reasonable amount of effort to determine the level of motivation in people participating. Mixing the simple request to perform a particular activity, with different levels of complexity or effort required, with money rewards allowed the research team to understand the way behavior and decisions in the work field are under the effect of cannabis.
In a 2013 study, this phenomenon was examined in UCL as well. That investigation found out that marijuana lowers the dopamine levels in the human body, the chemical component linked with ambition and motivation at a neuronal level.
In that case, scientists decided to evaluate PET brain imaging of cannabis’ users to check their levels of dopamine in the brain’s activity and frequent smokers, as well as people who started smoking at a young age, had the lowest.
A volunteer’s work
More than 50 people agreed to participate in the research. Volunteers were split into two groups to develop two separate studies. Group A involved adults who used cannabis occasionally and in this research they were exposed to marijuana vapor and placebo vapor.
Once they inhaled the substance, they were asked to choose between a low effort task and one with a higher lever of effort required to win different sums of money. Both tasks involved simple activities using keyboards. The strong effort option included a reward of £2 while the low energy tasks would make the subjects receive just 50p. The rewards allowed scientists to discover the role of money as principal motivation to perform the activity or complete the task.
“We found that people on cannabis were significantly less likely to choose the high-effort option. On average, volunteers on placebo chose the high-effort option 50% of the time for a £2 reward, whereas volunteers on cannabis only chose the high-effort option 42% of the time,” said Professor Val Curran, senior author of the research.
On the other hand, frequent users of cannabis and people addicted to it participated in the study performed for the Group B. Those participants were matched with 20 control participants who used other types of drugs. It was not allowed the use of substances other than tobacco or coffee for 12 hours before the study.
They were asked to choose between the two same tasks (low and high effort with keyboards), and the results showed that people addicted to cannabis had the same motivation levels than those in the control group.
In this sense, frequent cannabis users were no less motivated than others, which gives a new input to the understanding of the relationship between high levels of marijuana use and possible motivational deficits.