Deconstructing the trip treatment: are hallucinogenic effects critical to the therapeutic benefits of psychedelics?

The term 'hallucinogen' is a misleading label for drugs like ketamine, MDMA, and psilocybin, which rarely cause true hallucinations (false perceptions believed to be real). Instead, they produce perceptual alterations such as pseudo-hallucinations, synaesthesia, and illusions, along with changes in thinking, emotions, sense of time, self, and bodily awareness. These subjective effects—not hallucinations—are more often linked to therapeutic benefits. Historically, terms like psychotomimetics, phantastica, and psychedelics have been used, reflecting the complex mind-altering effects of these substances.

Study at a glance

Abstract

Interest in “psychedelic therapies,” using substances such as ketamine, 3,4-methylenedioxymethamphetamine (MDMA), and psilocybin to treat psychiatric conditions, has grown steadily in recent years. Although pharmacologically distinct and functioning via differential mechanisms, these drugs are broadly classified as hallucinogenic, meaning they are thought to produce hallucinations. However, this is contentious as evidenced by the wide-ranging terminology used historically to describe them. In addition to ‘hallucinogens,’ early researchers proposed such drugs might variably be called psychotomimetics (mimicking psychosis), phantastica (enhancing fantasy and imagination), and psychedelics (mind-manifesting) [ 1 ], highlighting the profound, complex mind-altering effects these substances can elicit. From a technical standpoint, most hallucinogens rarely induce true hallucinations where individuals experience false perceptions they believe to be genuine, though perceptual alterations like pseudo-hallucinations, synaesthesia, and illusions are common (Table 1 ). Furthermore, changes in higher-order processes like thinking, emotions, sense of time, self, and bodily awareness are typical, and these subjective effects have more often been linked to therapeutic changes than hallucinations per se . Table 1 Glossary of key terms. Full size table