Natural hallucinogens, such as psilocybin, mescaline, N,N-dimethyltryptamine (DMT) and related compounds, have generally received attention for their effects on human perception, emotion and cognition. Recently, interest in these compounds has expanded to include their potential roles in psychiatric treatment, neuroplasticity research and the study of consciousness.

Yet their ecological origins remain poorly understood. Why have unrelated plants, fungi and animals repeatedly evolved molecules capable of strongly modulating animal nervous systems?

Now, researchers led by Prof. Wang Xiaohui from the Changchun Institute of Applied Chemistry of the Chinese Academy of Sciences propose that natural hallucinogens may have primarily evolved as ecological tools that help organisms survive, defend themselves and interact with other species.

The research was discussed in a Perspective published in PNAS.

Chemical ecology offers a new frame
The study integrates chemical ecology, comparative genomics, biosynthesis, neuropharmacology and evolutionary biology to create an ecological and evolutionary framework for understanding psychoactive natural products.

The researchers argue that natural hallucinogens should be viewed as products of chemical ecology—the study of how organisms use chemicals to interact with one another and with their environment—and of convergent evolution, in which similar traits evolve independently in unrelated organisms because they face similar environmental challenges.

According to the study, these hallucinogenic compounds are not accidental "chemical anomalies." Rather, they may represent ecological tools shaped by interactions among producer organisms and their consumers, predators, competitors or symbiotic partners.