the Psychiatry Advisor take:

The belief that smoking marijuana unleashes creativity in some individuals is a myth, based on research conducted in the Netherlands.

Lorenza Colzato, PhD, of Leiden University and colleagues found that the active ingredient in marijuana, THC, actually impairs thinking, based on their study in 54 people.

Participants, who were all regular cannabis users, were divided equally into three groups. One was given highly potent cannabis (highest levels of THC), another was given a less powerful form of the drug and a third group was given placebo.

Participants were asked to complete a variety of tasks to measure convergent and divergent thinking. The former involved asking them to name as many uses for a common household item, such as a pen. The latter asked participants to find an association between three unrelated words.

Overall, participants in the most potent marijuana group fared the worst on the tasks, the researchers reported in the journal Psychopharmacology.

“The frequently reported feeling of heightened creativity could be an illusion,” the researchers wrote. “In other words, smoking a joint may not be the best choice when in need of breaking the ‘writer’s block’ or overcoming other artistic inhibitions, and smoking several of them might actually be counter-productive."