A review of the clinical effects of psychotomimetic agents

Osmond reviews a long history of substances that alter perception, thought and mood and have been variously labelled schizogens, hallucinogens, psychotogens and related terms. He argues that these agents have been used across cultures for millennia and that modern chemistry and psychopharmacology have produced synthetics (for example mescaline, LSD, TMA, bufotenin) that permit systematic clinical and experimental investigation. Although these drugs are often discussed for their capacity to mimic aspects of psychosis, Osmond emphasises that this is only one aspect of their significance: they also have potential roles in psychotherapy, training, research into normal and abnormal cognition, and broader social, philosophical and religious enquiry. The paper sets out to survey the clinical effects and uses of these compounds, to propose a working definition that delimits the group of interest, to highlight gaps and methodological problems in existing work, and to suggest a more inclusive nomenclature. Osmond therefore combines historical description, summaries of experimental ‘‘model psychoses,’’ clinical observations (including psychotherapy reports), and reflections on implications for psychology and psychiatry, while calling for more rigorous multidisciplinary research.

The extracted text presents a narrative, discursive review rather than a systematic, reproducible meta-analysis. Osmond draws on historical sources, ethnobotanical reports, early chemical syntheses, animal experiments, volunteer laboratory studies, clinical case series (some published, some described as unpublished), and his own and colleagues' clinical experience. The paper does not describe a formal literature search strategy, inclusion/exclusion criteria, quality assessment, or quantitative pooling of results. Instead, it synthesises diverse types of evidence qualitatively: comparisons between agents (mescaline, LSD, bufotenin, adrenochrome/adrenolutin and others), accounts of experimental model psychoses in volunteers, observations about pharmacological antagonists and modulators, and clinical reports of therapeutic applications in alcoholism and chronic psychiatric disorders. Where methodological details are important (for example, instability of adrenochrome or variability between batches of compounds), Osmond reports them as practical obstacles to replication; the extracted text does not provide systematic data on sample sizes, effect estimates, or statistical methods.

Osmond presents several interconnected findings and observations drawn from historical, experimental and clinical sources. He proposes a working definition of ‘‘psychotomimetic agents’’ as substances that produce changes in thought, perception, mood and sometimes posture without major autonomic disturbance or addictive craving, while excluding agents such as morphine, cocaine, atropine derivatives, anaesthetics, hypnotics and alcohol. Using that definition he surveys a wide range of natural and synthetic agents (soma, hashish, peyote/mescaline, caapi vine, Syrian rue, teonanacatl, Amanita species, iboga, virola snuff, mescaline, harmine, LSD, TMA, bufotenin, adrenochrome and adrenolutin). On model psychoses, he reports that earlier work has not settled whether different agents produce qualitatively distinct experiences or merely quantitative differences; many comparisons have failed to control for host factors (body type, culture, personality, hepatic function). He highlights LSD's unusual pharmacology—noting its very small effective dose and the paradox that most of the drug is reportedly excreted within about 1 hour while subjective effects may last 12 hours or more. Osmond and colleagues pursued adrenochrome and adrenolutin as potentially subtler, more insidious psychotomimetics that might better model slowly developing psychoses; however, chemical instability and difficulties of synthesis have limited reproducibility across laboratories. Several modulators and antagonists of the model states are described. Chlorpromazine, reserpine and sodium amytal were reported to attenuate LSD or mescaline models in some studies. Mayer‑Gross observed that perceptual change induced by LSD is reduced when blood sugar exceeds about 200 µg per cent. Nicotinic acid, Frenquel (azacyclonal) and sodium succinate were also noted as modifiers in different contexts. Aggravating or prolonging factors include prior liver damage (which can lengthen mescaline and adrenochrome responses), atropine derivatives, methedrine (which prolongs and reactivates LSD effects), and high levels of CO2 or hyperoxia in isolated reports; sensory inputs such as stroboscopic light were observed to enhance some model features. On therapeutic use, Osmond summarises varied clinical approaches rather than definitive trials. Abramson is cited for repeated small LSD doses within a modified psychoanalytic framework; Sandison for variable-dose group/Jungian work in chronic neurotics; Frederking for a large series comparing mescaline and LSD with psychoanalytic techniques; and other clinicians (including Hubbard) for large unpublished series treating severe alcoholism, with some reports of marked benefit. Osmond reports that single high-dose experiences have been reported as useful in alcoholism but that repeated treatments often appear necessary. He warns that mentally ill patients can be worsened by LSD and that tolerance develops after LSD use. The extracted text does not give clear, reproducible sample sizes, controlled outcomes, or standardised effect estimates for these therapeutic claims. Psychological observations include enhancement of empathy, induction of synaesthesia, depersonalisation phenomena, and perceptual changes that many subjects call ‘‘unforgettable’’ or ‘‘indescribable.’’ Osmond emphasises that many users—ranging from indigenous peyote takers to artists and scientists—report profound, often valuable subjective experiences that frequently resist verbal description. Finally, he proposes ‘‘psychedelic’’ (mind‑manifesting) as a preferred umbrella term, arguing that ‘‘psychotomimetic’’ is too narrowly pathological.

Osmond interprets the surveyed evidence as indicating that these substances are important for more than modelling psychosis: they can be research tools for psychopathology and normal-minded processes, adjuncts in psychotherapy and staff training, and instruments with social, philosophical and possibly spiritual significance. He stresses that their unique experiential qualities require study from multiple disciplinary perspectives and that investigators should ideally be experienced with the agents they study to improve observation and interpretation. The author acknowledges substantial limitations and uncertainties: much of the evidence is anecdotal or unpublished, chemical instability (notably of adrenochrome/adrenolutin) and batch variability impede replication, and existing experiments often fail to control for host variables (metabolism, prior exposures, personality, cultural context). Osmond warns that certain patients (psychotics, neurotics, epileptics, alcoholics, ‘‘psychopaths’’ in his terms) may be unsuitable for experimental work and that some agents can worsen psychiatric illness. He also notes safety concerns relevant to real‑world settings (interactions with liver disease, alcohol, stimulants, anticholinergics; impairment of driving and complex tasks) and the need for careful attention to set and setting. Given these constraints, Osmond argues for cautious optimism: the substances may have therapeutic and educational value but require rigorous, multidisciplinary research, improved chemistry and standardisation, systematic measurement schedules (physiological, electrophysiological, biochemical, psychological and social), and appropriate ethical oversight. He advances ‘‘psychedelic’’ as a more inclusive term and calls for support from foundations, governments and industry to pursue coordinated research. The extracted text thus frames strong hypotheses and practical priorities, while emphasising that definitive clinical claims are not yet warranted.

In his closing summary, Osmond reiterates that a broad family of agents produces changes in thought, perception and mood but that ‘‘psychotomimetic’’ is an inadequate generic term because these substances do more than mimic illness. He offers a working definition intended to exclude anaesthetics, hypnotics, addictive drugs and major autonomic toxins, and he highlights large gaps in knowledge—chemical, clinical and methodological—that have slowed progress. While noting early therapeutic reports (particularly in alcoholism and some chronic conditions), he stresses that evidence is limited and that careful, skilled research is required. Osmond concludes by proposing ‘‘psychedelic’’ (mind‑manifesting) as his preferred term and urging disciplined, compassionate application of these agents in research, training and, cautiously, in therapy.