“I smoke pot because I want to go to heaven before I die”
Andy Warhol

Anecdotal evidence suggests that cannabis intoxication enhances human creativity. In line with that, Steve Jobs, an undeniably creative mind, once stated: “The best way I could describe the effect of the marijuana and hashish is that it would make me relaxed and creative". Other regular users claim that cannabis induces a state in which they experience unusual and original thoughts (Tart 1970). In a more recent review, over 50% of users reported heightened creativity during cannabis intoxication (Green et al. 2003). This widespread perception of cannabis as a creativity-enhancer makes it important to verify whether cannabis actually induces these supposed effects.

For the first time, at Leiden University we investigated the effects of a low (5.5 mg THC) or high (22 mg THC) dose of vaporized cannabis vs. placebo on the two main ingredients of creativity: divergent and convergent styles of thinking.
• Divergent thinking allows many new ideas to be generated. It is measured using the so-called Alternate Uses Task method where participants are required to think up as many uses as possible for a particular object, such as a pen.
• Convergent thinking, on the other hand, is a process whereby one possible solution for a particular problem is generated. This method is measured using the Remote Associates Task, where three unrelated words are presented to the participants, words such as 'time', 'hair' and 'stretch'. The participants are then asked to identify the common link: in this case, 'long'.

High dose cannabis decreases creativity

Participants in the high dose group (n = 18) displayed significantly worse performance on the divergent thinking task, compared to individuals in both the low dose (n = 18) and placebo (n = 18) group. The findings suggest that cannabis with low potency does not have any impact on creativity while highly potent cannabis actually impairs divergent thinking.

The illusion of the creative joint

The phenomenological experience of a person intoxicated with cannabis might not necessarily reflect his or her actual performance. In particular, the frequently reported feeling of heightened creativity could be an illusion. 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.

Kowal, M., Hazekamp, A., Colzato, L.S., van Steenbergen, H., van der Wee, N., Durieux, J., Manai, M., & Hommel, B. (2014). Cannabis and creativity: highly potent cannabis impairs divergent thinking in regular cannabis users. Psychopharmacology.