You know that part in the movie where the writer just can’t seem to find that creative spark, so they light up a joint to help get them over their mental hurdle? Well that’s BS. It turns out that marijuana does not lead to creative thinking and may even inhibit it. A recent study conducted by researchers from Leiden University in the Netherlands has revealed that smoking cannabis to improve creativity is a sham and actually counterproductive.

“The improved creativity that they believe they experience is an illusion,” Dr. Lorenza Colzato, assistant professor of neuromodulation of cognition at Institute of Psychology, Leiden University, said in a statement. “If you want to overcome writer's block or any other creative gap, lighting up a joint isn't the best solution. Smoking several joints one after the other can even be counterproductive to creative thinking.”

Colzato and her colleague, Dr. Mikael Kowal, recruited 54 marijuana smoking participants and divided them into three groups of 18. Researchers provided the first group marijuana with 22 mg of THC (equivalent to “three joints”), the second group marijuana with 5.5 mg of THC (equivalent to a “single joint), and the third group a placebo. Marijuana was inhaled via a vaporizer, and participants were not told what dose they were receiving or if it was a placebo.

After administering the marijuana, the research team gauged each participant’s ability to complete cognitive tasks that included two types of creative thinking. The first task: "Think of as many uses as you can for a pen" tested divergent thinking, or the ability to generate rapid solutions for a given problem. The second task: "What is the link between the words 'time', 'hair,' and 'stretching'” (The answer is 'long') tested convergent thinking, or the ability to find the only right answer to a question.

Receiving the highest dose of THC had a negative effect on the participant’s ability to come up with solutions for the tasks they were asked to perform. Although participants in the low dose or placebo groups displayed better creative thinking skills compared to participants in the high dose group, there were no signs of increased creativity in their actual performance. These findings refute any evidence suggesting that smoking pot changes thinking and makes it more original.

Source: Hazekamp A, Kowal M, Colzato L, et al. Cannabis and creativity: highly potent cannabis impairs divergent thinking in regular cannabis users. Psychopharmacology, 2014.