The Tolerability and Safety of Psilocybin in Psychiatric and Substance-Dependence Conditions: A Systematic Review

A retrospective study of the characteristics and toxicology of cases of lysergic acid diethylamide (LSD)- and psilocybin-related death in Australia

BACKGROUND AND AIMS

Lysergic acid diethylamide (LSD) and psilocybin are used as recreational drugs, and there is renewed interest in their clinical use. The current study aimed to (1) determine the circumstances of death and case characteristics of LSD- and psilocybin-related death in Australia, 2000-23; and (2) determine the toxicological profile and major autopsy findings of these cases.

METHODS

This was a retrospective exploratory study of all cases of LSD- and psilocybin-related death in Australia, 2000-23, retrieved from the National Coronial Information System.

RESULTS

A total of 43 cases were identified: 33 LSD and 10 psilocybin. The median ages were 24 years [interquartile range (IQR) = 13, range = 16-53] (LSD) and 26 years (IQR = 18.5, range = 20-58) (psilocybin), and fewer than five cases were female. The most common circumstance of death among both groups was traumatic accident (LSD 36.4%, psilocybin 40.0%). There were 12 cases of self-harm, all of which involved LSD, all by physical means. In a fifth, death was attributed to multiple drug toxicity (LSD 18.2%, psilocybin 20.0%). In one case, death was attributed solely to LSD toxicity, while in a further two cases death was attributed to a cardiovascular event following LSD consumption (one LSD only, one multiple drug toxicity). In four psilocybin cases, the cause of death was undetermined. The most common clinical presentation was severe agitation (LSD 27.3%, psilocybin 20.0%). Median blood concentrations were LSD 0.8 μg/l (IQR = 1.7, range = 0.1-3), psilocin 20 μg/l (IQR = 53.5, range = 6-83). LSD was the only drug present in 25.0% of LSD cases and psilocybin in 20.0% of psilocybin cases. Pre-existing organ pathology was uncommon.

CONCLUSIONS

Lysergic acid diethylamide (LSD)- and psilocybin-related death in Australia from 2000 to 2023 was primarily due to traumatic injury, whether through accident or self-harm. Cases of acute toxic reactions that were attributed solely to LSD were rare.

Are "mystical experiences" essential for antidepressant actions of ketamine and the classic psychedelics?

The growing interest in the rapid and sustained antidepressant effects of the dissociative anesthetic ketamine and classic psychedelics, such as psilocybin, is remarkable. However, both ketamine and psychedelics are known to induce acute mystical experiences; ketamine can cause dissociative symptoms such as out-of-body experience, while psychedelics typically bring about hallucinogenic experiences, like a profound sense of unity with the universe or nature. The role of these mystical experiences in enhancing the antidepressant outcomes for patients with depression is currently an area of ongoing investigation and debate. Clinical studies have shown that the dissociative symptoms following the administration of ketamine or (S)-ketamine (esketamine) are not directly linked to their antidepressant properties. In contrast, the antidepressant potential of (R)-ketamine (arketamine), thought to lack dissociative side effects, has yet to be conclusively proven in large-scale clinical trials. Moreover, although the activation of the serotonin 5-HT2A receptor is crucial for the hallucinogenic effects of psychedelics in humans, its precise role in their antidepressant action is still under discussion. This article explores the importance of mystical experiences in enhancing the antidepressant efficacy of both ketamine and classic psychedelics.