Despite increasing awareness of the need for diversity in clinical research, psychedelic studies have shown limited ethnoracial representation.
A systematic review of 39 studies on psychedelic treatments for psychiatric or substance use disorders, published between January 1, 1994, and May 24, 2024, highlights this ongoing issue. The review, including 16 studies (n = 282) from a 2018 review and 23 new studies (n = 1111), revealed that participants in studies published after 2017 were predominantly non-Hispanic White (85.6%), with minimal representation of Black (3.1%), Latinx/Hispanic (6.8%), Asian (3.6%), Indigenous (1.2%), mixed race (3.5%), and other (1.4%) individuals.
In the USA, White participants constituted 84.5% of the study population, with a slightly higher representation of ethnoracial minorities compared to global data. Although there has been some progress in including more diverse populations in the USA since 2018, this trend is not observed globally.
The findings indicate that while steps towards equity in psychedelic research are being made, significant efforts are still required to ensure these treatments are tested for safety and efficacy across a representative population.