Emerging therapeutic opportunities for psychedelic and related drugs.

Increasing interest in psychedelic and related drugs as potential therapies for a wide spectrum of difficult-to-treat conditions, that extend beyond neuropsychiatric disorders, provided the impetus for this themed issue. This collection of reviews and original articles includes the mechanistic basis of how these drugs act, the current status of preclinical research and progress in clinical trials, and insight into the regulatory processes that determine clinical approval. In this editorial, we introduce these aspects and provide an overview of current controversies and challenges in the field, as well as highlighting the exciting potential that these drugs offer. LINKED ARTICLES: This article is part of a themed issue Emerging Therapeutic Opportunities for Psychedelic and Related Drugs. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v183.14/issuetoc.