Psilocybin in the treatment of anorexia nervosa: The English transition of a French 1959 case study

Verroust and colleagues situate psilocybin historically and clinically: the compound was chemically characterised in 1958 after ethnobotanical observations of ritual mushroom use and early laboratory work at the Muséum national d'Histoire naturelle and Sandoz. Early psychiatric experimentation with psilocybin took place at Sainte-Anne Hospital in Paris under Jean Delay's team, which included the 1959 case report of a 35-year-old woman hospitalised for compulsive eating and anorexia nervosa who reportedly had a rapid and sustained improvement after two injections. This paper presents an English translation of that 1959 French case report (original title translated as “Therapeutic effect of psilocybin on a compulsive neurosis”) to make the clinical observations accessible to current researchers. The authors frame the case as historically important given the current resurgence of clinical research into serotonergic psychedelics for psychiatric disorders, including ongoing trials of psilocybin in anorexia nervosa, and as potentially informative about therapeutic mechanisms such as emotional breakthrough and autobiographical insight.

This paper is a translation and presentation of a single historical clinical case rather than a new experimental study. The investigators translated the original 1959 French report of one patient treated with injectable psilocybin at Sainte-Anne Hospital and supplemented that with contextual discussion of psilocybin's pharmacology, early clinical use, and contemporary theoretical frameworks for psychedelic-assisted therapy. No new data collection, randomisation, or statistical analysis was performed. The source case report supplies the clinical observations, family and developmental history, examination findings, medication status, details of the timing of the two psilocybin injections, and the clinical course following treatment. Where the original report omitted specific details (for example, the psilocybin dose is not reported in the extracted text), the translators note that such values are not clearly provided. Given the nature of the source material, key methodological constraints are that the evidence is from a single patient, the intervention was not delivered within contemporary manualised psychedelic-assisted psychotherapy (no report of formal psychological preparation or integration), and concomitant psychotropic medication (chlorpromazine/Largactil) was present at the time of the first injection and withdrawn before the second.

The case concerns Miss Henriette B., aged 35, employed in a tax office and admitted on 23 March 1959 for compulsive eating behaviours accompanied by marked weight loss; at admission she weighed about 40 kg for 1.69 m and had amenorrhoea and depressive symptoms. The extracted text includes extensive family, developmental and psychosocial history: a dominant, material-focused mother, early episodes of anorexia around age 5–6, academic disappointments, rigid routines, ritualised behaviour, emotional immaturity and longstanding feelings of guilt and inferiority. On admission she was treated with chlorpromazine (Largactil) 100 mg daily with little improvement; the first psilocybin injection was given on 20 April 1959 while chlorpromazine treatment continued. The report describes early neurovegetative effects and, later, pronounced psychological phenomena including polysensory hallucinations, euphoria, mystical imagery and prolific poetic expression. The patient described a sense of liberation from her body and declared, among other expressions, “I don't have a body anymore; I am only a soul and I am real.” No specific psilocybin dose is reported in the extracted text. A second injection was administered four days later after Largactil had been suspended. This session produced a brief semi‑confusional period with mystical content followed by approximately two hours of intense emotional reliving and autobiographical recall. During this phase she verbalised a range of themes: longstanding emotional deprivation and aggression toward her mother, attachment to a neighbour and an influential schoolteacher, early onset of anorexia coinciding with separation from the neighbour, persistent guilt, sexual difficulties, and feelings of inferiority. The narrative records several verbatim expressions directed at her mother and childhood figures. Clinical outcome was reported as rapid and marked. The day after the second injection the patient was euphoric, and over the following month her weight increased by 7 kg by discharge. The authors of the original report considered the therapeutic effect to be clear. The translated paper also notes an authorial footnote that Anne‑Marie Quétin's 1960 thesis indicates the patient was depressed again at one year, suggesting the improvement may not have been fully durable. Adverse effects recorded in the extraction were limited to transient semi‑confusional state and physical discomfort during the second session; no systematic safety data are presented.

The translators and the original 1959 authors interpret the case as evidence that psilocybin produced a therapeutically meaningful emotional breakthrough that allowed the patient to access autobiographical memories and gain insight into the psychogenesis of her eating disorder. They emphasise the contrast between the first injection given whilst the patient was receiving chlorpromazine, which produced perceptual and euphoric phenomena without emotional breakthrough, and the second injection given after chlorpromazine withdrawal, which precipitated intense emotional reliving and verbalisation of core conflicts that the authors link to subsequent improvement. Verroust and colleagues place this observation in the context of current theories about psychedelic mechanisms, citing ideas such as relaxation of rigid prior beliefs and transient hyper‑plasticity that may permit reframing of self‑related beliefs; they also note contemporary procedural differences, particularly the routine use of psychological preparation and integration in modern psilocybin‑assisted therapy, which were not reported in the historical case. Naturalistic and trial evidence is referenced to argue that psychedelic experiences can increase self‑acceptance and decrease depressive symptoms in people with eating disorders, supporting the rationale for current clinical trials in anorexia nervosa. The authors acknowledge limitations inherent to the case: it is a single uncontrolled observation, concomitant medication may have influenced acute effects, and the extracted text does not provide dose information or standardised outcome measures. They also draw attention to evidence suggesting the patient's relief may not have been permanently sustained at one year, and they note that modern protocols emphasise integration as central to durable benefit—an element absent from the historical report. A brief remark in the original discussion by a commentator (Mr Dublineau) raised the possibility of an EEG abnormality and a para‑convulsive dysrhythmic reaction, but the extracted material treats this as a speculative observation rather than a definitive finding.

The original 1959 report concluded that psilocybin produced an indisputable therapeutic action in this patient, with the second injection—given without concurrent chlorpromazine—leading to autobiographical recollection, intellectual and affective awareness of problems, and a rapid mood and weight recovery. The authors attribute the clinical change mainly to the emotional reliving and insight elicited by the second session. The translated paper notes, however, that subsequent material (Quétin's thesis) indicates a recurrence of depression at one year, underscoring uncertainty about long‑term durability in this single case.