Your Mom Was Right: Weed Really Does Kill Your Motivation, Says New Study

You may not want to get baked before you start looking for your next job.

According to a new study, smoking a joint really does affect your motivation to work – at least in the short-term.

While the idea that weed kills your motivation has long been touted by uptight moms everywhere, this research, published in Psychopharmacology, is the first of its kind to reliably demonstrate the short-term effect of cannabis on motivation in humans.


However, it’s important to note that habitual marijuana use was not correlated with lowered motivation.

The researchers also looked at people who were addicted to weed but not high during the test and found their motivation levels were no different to volunteers in the control group.

“Although cannabis is commonly thought to reduce motivation, this is the first time it has been reliably tested and quantified using an appropriate sample size and methodology,” says lead author Dr. Will Lawn.

“It has also been proposed that long-term cannabis users might also have problems with motivation even when they are not high. However, we compared people dependent on cannabis to similar controls, when neither group was intoxicated, and did not find a difference in motivation,” he says.


He says this tentatively suggests that long-term cannabis use may not result in residual motivation problems when people stop using it (good news for the stoners out there).

The research consisted of two separate studies and included 57 adult volunteers.

The first involved 17 volunteers who used cannabis occasionally. Through a balloon, they inhaled cannabis vapour on one occasion and cannabis-placebo vapour on another occasion. Immediately after, they completed a task designed to assess their motivation for earning money. In completion of the task, the volunteers were given money they had earned at the end of the experiment.


For each task, volunteers could choose whether to complete low or high-effort tasks to win varying sums of money.

The low-effort option involved pressing the spacebar key with the little finger of their non-dominant hand 30 times in 7 seconds to win 50p (a task that is probably actually more difficult to do stoned than you would imagine).

The high-effort option involved pressing the space bar 100 times in 21 seconds, for rewards varying from 80p to £2.

“Repeatedly pressing keys with a single finger isn’t difficult but it takes a reasonable amount of effort, making it a useful test of motivation,” explains senior author Professor Val Curran. “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.”


The second study involved 20 people who were addicted to weed and matched with 20 control participants who reported the same levels of non-weed drug use.

Participants were not allowed to consume alcohol or drugs (other than tobacco or coffee, if that even counts) for 12 hours prior to the study and asked to perform the same motivation task as participants in the first study.

The results showed that the weed-dependent volunteers were no less motivated than the control group.

Before you revisit your high school weed habit, remember that a lot more research is needed to fully understand the relationship between long-term cannabis use and its affect on motivation. The researchers stress that longitudinal research is needed to provide more conclusive evidence.

Cover photo: Chuck Grimmett (cropped from original)

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