marijuana makes you lazy

It’s official: one joint of cannabis makes you lazy … but only in the short term


Post-doctoral researcher, UCL

Disclosure statement

Will Lawn received funding from the BBSRC.


University College London provides funding as a founding partner of The Conversation UK.

The Conversation UK receives funding from these organisations

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I was gonna go to work but then I got high
I just got a new promotion but I got high
Now I’m selling dope and I know why
‘Cause I got high
Because I got high
Because I got high

Afroman’s 2001 hit Because I Got High tells a potentially important story: smoking cannabis makes you lazy and demotivated. In fact, the fable of the lazy stoner has been around for decades. But is there good evidence in support of it?

Two studies we have been working on have investigated the claim that cannabis leads to reduced motivation. We found that when you give people the equivalent of one spliff’s worth of cannabis, under controlled conditions in a laboratory, they are less willing to work for money. In other words, they are not as motivated as usual. However, we also compared people who are addicted to cannabis with a control group (non-cannabis drug users). We found that when neither group had used drugs for at least 12 hours, they did not differ in their motivation for money.

Our results suggest that when you have recently smoked cannabis, it reduces your motivation in the short-term. On the other hand, long-term cannabis use may not impair your motivation, as long as you stop smoking it for at least 12 hours.

‘Amotivational syndrome’

In the late 1950s and 1960s, as cannabis became a popular recreational drug, academic reports of cannabis’s “amotivational syndrome” appeared. Clinicians stated that “regular marihuana [sic] use may contribute to the development of more passive, inward turning, amotivational personality characteristics”. However, these reports simply relied on observations of cannabis users and their lazy behaviour. Research was needed to investigate the short and long-term effects of cannabis.

Early research into the short-term effects of cannabis on motivation surprisingly found both motivating and demotivating effects of cannabis. Having said that, these studies were poorly controlled and sometimes rather bizarre in their design; one involved getting people stoned and asking them to make stools as quickly as possible. A more recent study gave cannabis to people in a placebo-controlled experiment and reported reduced motivation for money. However, this experiment used a very small sample of five participants.

Our new study used a double-blind, placebo-controlled design to examine the effects of cannabis on motivation for money in a larger sample of 17 participants. Through a balloon, participants inhaled cannabis vapour on one occasion and a placebo cannabis vapour on a separate occasion. Straight after, they completed a task designed to measure their motivation for earning money. This was a real-life task as the participants were given money they had earned at the end of the experiment. In each trial, they could decide whether to complete low or high-effort options to win varying sums of money. The low-effort option involved pressing the spacebar key 30 times in seven seconds to win 50p. The high-effort option involved 100 space bar presses in 21 seconds for rewards varying from 80p to £2.

One hundred spacebar presses equals more cash. BaLL LunLa/

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. In other words, they had reduced motivation for the money available when they were stoned. Although it has been a long-held belief that getting high makes you lazy, this is the first time it has been reliably demonstrated using a suitable sample size.

No difference

The question of whether long-term cannabis use makes people demotivated, even when they’re not high, is a more difficult one to answer. We cannot carry out randomised controlled trials in which some people are given cannabis for ten years while another group receive placebo for ten years. That would, of course, be unethical. Therefore, we have to rely on observational studies, where we look at associations between natural cannabis consumption and motivation levels. Some previous research has failed to find a link between cannabis use and altered motivation, although in one study earlier cannabis consumption predicted later anhedonia (difficulty experiencing pleasure).

In our observational study (that is, one that does not have an experimental manipulation), we compared 20 people who were addicted to cannabis against a control group of 20 people who were not addicted to cannabis. The control group used other drugs, including MDMA and cocaine, a similar amount to the cannabis group. These participants completed the same motivation task as in the previous study after they had been clean of all drugs (apart from tobacco and caffeine) for at least 12 hours. We found no difference between the groups in their willingness to work for money. This suggests that long-term cannabis use may not reduce motivation after 12 hours of abstinence from the drug.

However, there are some important limitations with this study. Firstly, the sample sizes were small. Secondly, the study was cross-sectional, so we only investigated the participants at one point in time. An improved study would have used a longitudinal design, in which people’s motivation and cannabis use are measured at different time points as they grow up. This would have allowed for a better understanding of how cannabis consumption affects future motivation. Longitudinal research is needed to draw stronger conclusions.

What do our results mean to the average cannabis user? After years of being told that getting high makes you lazier, we’ve provided some of the first solid evidence that it’s true. Importantly though, it doesn’t eradicate your motivation altogether – it makes you slightly, yet significantly, more apathetic. On the bright side, your long-term cannabis use may not erode your drive like some people claim, so long as you can put your joint down for a while.

A new study found that people who are high on cannabis are less likely to opt for a task with a larger reward if the task requires more effort.

Does Weed Really Make You Lazy?

Tuesday September 6, 2016

M any of those opposing marijuana reform insist that legalization would inevitably lead to a zombie apocalypse of sorts – a nation of lazy stoners who can’t find the motivation to get off the couch and get a job. Though the fear of a lazy stoner society is supported by articles and “research” backing the notion that heavy marijuana use causes laziness (a.k.a “Amotivational Syndrome” or AMS), a closer look at the research shows us that this isn’t necessarily the case.

What is Amotivational Syndrome?

“Amotivational syndrome” is characterized by a diminished desire to achieve goals. It often accompanies feelings of apathy, lethargy and depression. It can make it difficult to feel pride or satisfaction due to a reduction in dopamine production over time.

There is still debate about whether or not AMS is truly a medical condition. Some speculate that heavy marijuana use could lead to AMS while others point out that the occurrence is very rare and occurs with non-users as well, hinting at the possibility of other underlying conditions like depression.

Does Cannabis Cause Amotivational Syndrome?

Early research suggests that chronic, heavy use of marijuana could cause a decline in motivation, but the studies were small and didn’t account for other variables like a predisposition to depression. Nevertheless, opponents of marijuana reform continue to cite these outdated studies as reason enough to avoid legalization.

The U.S. Department of Health and Human Services has written a letter to parents warning of the dangers of youth marijuana consumption stating that young users are more likely to drop out of school and develop AMS. Though the document clearly states that AMS may or may not be caused by cannabis consumption, the assumption that it might is pretty clear.

Even if AMS is real, it only occurs in a handful of situations and those situations are not limited to cannabis consumption. According to a study published in the journal, Psychology of Addictive Behaviors, a survey of 237 college students found that only 5.6% of regular marijuana users developed symptoms of AMS; another 6.2% of non-users and 6.3% of occasional marijuana users also reported symptoms.

Interestingly, many marijuana users claim an increase in life satisfaction after marijuana consumption no matter how “successful” they appear to be. Though marijuana users tend to have lower levels of life satisfaction overall, much of this could be equated to poor health (and thus the need for medical marijuana) and not poor life decisions or a lack of motivation.

In a 2005 study published in BioMed Central, 1300 adults (ages 18 – 81) completed a survey on motivation and life satisfaction. The results showed little difference in motivation levels between marijuana users and non-users. The study did, however, find that daily marijuana users were slightly less likely to satisfied with life, though the difference disappeared when after removing medical marijuana users from the equation. Since medical marijuana patients often report high levels of pain, nausea and other physical difficulties, low life satisfaction among this group is likely due to their medical condition and not their treatment method.

So What Does Cause Amotivational Syndrome?

Assuming that AMS exists, it is likely caused by a number of different things (excessive drug use, eating, or sex, for example). According to Dr. George Simon, AMS is most likely born through addiction. Be it cannabis, pornography or even video games, those who have developed an addiction to instant gratification are more likely to experience symptoms of AMS due to an increased production of dopamine. When dopamine, the “feel good” hormone, is produced with little effort, motivation to accomplish long, drawn-out tasks to achieve the same feeling diminishes.

Unfortunately, excessive use of instant gratification sources can cause a reduction in natural dopamine production, a problem which is exacerbated by the fact that the number of dopamine receptors tends to be reduced when activated too often. To compensate, the user must use more of the substance just to experience the same lift in mood. Thus, it is the cycle of addiction that may cause AMS symptoms, not cannabis itself.

We’ve all heard the lazy stoner stereotype, and some have even gone so far as to give it a medical term. However, the notion that heavy marijuana use could inevitably lead to a clinically significant drop in motivation has been disproven time and time again; chronic cannabis use does not cause a drop in motivation, and the success of the marijuana movement proves it.

Marijuana has been linked to laziness and a lack of motivation, but some doctors suggest it's really Amotivational Syndrome (AMS). Some say excessive marijuana use can cause AMS, but research proves otherwise.