From 2000 to 2023 in Australia, 43 deaths involving LSD (33 cases) or psilocybin (10 cases) were identified. Most deaths were from traumatic accidents (36.4% for LSD, 40.0% for psilocybin) or self-harm by physical means (12 cases, all involving LSD). Multiple drug toxicity accounted for about a fifth of deaths. Only one death was attributed solely to LSD toxicity, and two followed a cardiovascular event after LSD use. In four psilocybin cases the cause was undetermined. Severe agitation was the most common clinical presentation. Median blood concentrations were 0.8 μg/l for LSD and 20 μg/l for psilocin. Pre-existing organ pathology was uncommon.
Research from the 1950s and 1960s on using LSD to treat alcohol dependence offers cautionary lessons for the current revival of psychedelic therapy. Early uncontrolled studies by Osmond and Hoffer reported that high doses of LSD induced mystical experiences that helped alcoholics embrace abstinence, with some reports claiming a 50% success rate. However, later controlled trials found no better outcomes in LSD-treated patients at 12–18 months follow-up, though a meta-analysis showed benefits up to 6 months. The history warns against irrational exuberance and emphasizes that psychedelics are not standalone cures; they require combination with aftercare and rigorous clinical trials before widespread use.