This survey study (n=787) found that Openness to experience was the strongest predictor of creativity (four measures), but self-reported drug use did have some (positive) effect on creativity.
“This study examined self-reported drug use (legal, illegal, and psychotropic) and creativity (using self-assessments, behavioral checklists, and a photo caption task). Drug usage was first analyzed using EFA and CFA; these factors were then entered into SEM analyses in order to predict creativity on each of the four measures while controlling for openness to experience. Although openness to experience was the strongest predictor of creativity on all scales, self-reported drug use did provide some incremental effects beyond personality on the creativity measures. Results are explained in terms of possible expectancy/placebo effects.”
Authors: Danielle E. Humphrey, Alexander S. McKay, Ricardo Primi & James C. Kaufman
“One of the top five reasons adolescents report for trying drugs is to raise their creativity” (Novacek, Raskin, & Hogan, 1991↗)
Talking about earlier research by Janiger and de Rios (1989).
“… conducted a 7-year longitudinal study on LSD use and artistic creativity. Consistent with Berge’s reviews, artists felt their art was affected and believed it exhibited notable differences from their previous work. However, there were very little differences objectively found in the artwork.”
“In the present study, we use a multi-method approach to assess creativity. We use three different self-report measures of creativity: a general self-report, an everyday creative behavioral checklist, and an artistic creative behavioral checklist. In addition, we have added a performance-based test: a photo caption-writing measure scored using qualified raters utilizing the Consensual Assessment Technique (Amabile, 1996)”
“Self-reported creativity was almost perfectly predicted by openness to experience due to the high correlation between these two factors indicating that these two scales measured roughly the same trait.”
And finally they make a strong statement that is supported by their findings:
“Many of the drug effects have appeared to be rooted in what people expect from the drugs rather actual physiological changes from the drugs.”