The use of illicit drugs as self-medication in the treatment of cluster headache: results from an Italian online survey

Cluster headache (CH) patients commonly seek both conventional and unconventional therapies and appear more prone than average to experimenting with illicit substances. Lorenzo and colleagues recount an unsolicited request from a CH patient for a prescription of an illicit hallucinogen and note that anecdotal literature has suggested benefit from hallucinogens, although randomised controlled trials are lacking. Initial local interviews of 110 CH patients identified only a small number who had used illicit drugs therapeutically, prompting the investigators to widen recruitment. To explore therapeutic use of illicit substances in a larger sample, the study team posted an invitation on the timeline of an Italian Facebook self‑help group for CH (more than 800 members) asking members to report experiences of using illicit drugs specifically to treat CH rather than for recreation. The stated aim was to identify which substances were used and what motivated patients to try these alternative treatments.

The researchers developed an online questionnaire collecting sociodemographic information, prior experience with conventional CH therapies, history of recreational illicit drug use, and lifetime use of illicit substances for CH treatment. The study received local ethics committee approval and the questionnaire was posted online during May and June 2014. Eligibility required a self‑reported diagnosis of CH by a neurologist (the diagnosis was not validated by the authors) and no recreational use of illicit drugs in the preceding year (self‑reported). Participants completed the online interview and data were entered anonymously. To protect confidentiality, the investigators deleted questionnaires and related emails from their computers and servers after data entry. The extracted text does not report any statistical analysis plan or other analytic methods, and the authors explicitly stated they did not intend to estimate the prevalence of illicit drug use for CH in the wider patient population.

Fifty‑four respondents (6.75% of the Facebook group members) reported lifetime use of at least one illicit drug to treat CH and stated they had not used these drugs recreationally within the previous year. The sample comprised 35 men and 19 women; 23 (42.6%) were married, 8 (14.8%) had a university bachelor’s or postgraduate degree, 46 (85.2%) were employed, and 43 (79.6%) reported household annual income below €36,000. Clinically, 29 participants (53.7%) were classified as chronic CH at the time they first used illicit drugs and 39 (72.2%) were described as drug‑resistant (refractory to all tried preventive pharmacotherapies). High health‑care use was reported: 41 patients (75.9%) had consulted at least three different headache specialists and 40 (74.1%) had more than ten headache‑related visits in their lifetime. Regarding conventional therapies, 50 patients (92.6%) had tried subcutaneous sumatriptan, 40 (74.1%) had tried oxygen therapy (dose and delivery method not reported), and 48 (85.7%) had tried at least one prophylactic treatment (dosages not reported); 25 (46.3%) had tried at least three different prophylactics. All respondents reported dissatisfaction with conventional treatments in terms of efficacy and/or tolerability. Only 3 participants (5.6%) said a physician had suggested illicit drug use; 94.4% reported receiving suggestions from other patients or finding recommendations on the Internet. Prior to first therapeutic use of an illicit drug, 24 patients (44.4%) had used illicit substances recreationally at least once; 22 (40.7%) informed their physician of their decision despite dissuasion, and 18 (33.3%) did not seek medical consultation before use. After starting illicit drug use for CH, 30 patients (55.6%) chose not to pursue further medical consultations; 19 (35.2%) disclosed their use to a physician, after which the physicians declared they were unable to continue care. Those denials did not generally lead patients to stop the illicit treatments. Reported therapeutic agents and patterns included 34 patients using cannabinoids, 13 using cocaine, and 8 using intravenous heroin as abortive treatments; 18 used psilocybin (PSI), 12 lysergic acid amide (LSA), and 4 lysergic acid diethylamide (LSD) as prophylactic agents. In two cases PSI, LSA, and LSD were reportedly used at sub‑hallucinogenic doses. The paper refers to a table with patients’ self‑reports of effectiveness (table not included in the extracted text). A small number of cases are noted in the extraction as reporting prophylactic effects from agents initially assumed to be abortive (three patients described a delay in clusters or bouts), and one patient reported sudden disappearance of pain after an infusion while others described only greater tolerability. Regarding perceived safety and legality, 48 patients (85.7%) did not view these agents as less safe than conventional treatments and 30 (55.6%) considered them safer; only 4 patients (7.4%) reported concern about legal consequences.

Lorenzo and colleagues describe this work as the first survey examining deliberate consumption of illicit drugs by patients to treat CH. They emphasise that the sample is not representative of the wider CH population and point to selection bias inherent in recruiting from a self‑help group, where members are likely to have more severe or treatment‑resistant disease and to seek alternatives. For that reason, the investigators did not attempt to estimate overall rates of illicit‑drug use for CH. The respondents were predominantly chronic and drug‑resistant cases with high consultation rates, and most had tried standard acute and prophylactic treatments despite incomplete reporting of dosing. All reported dissatisfaction with conventional care; many chose to try illicit drugs without medical advice or against physician recommendations. The authors highlight a concerning pattern in which disclosure of illicit use led some physicians to discontinue care, coinciding with patients abandoning conventional medical care and turning to peer and Internet advice. Six categories of illicit drugs were identified: cannabinoids, cocaine, heroin, LSD, LSA, and psilocybin. The authors refrain from asserting effectiveness from these self‑reports but note patterns: substances used as abortive agents (cannabinoids, heroin, cocaine) were often self‑rated as of low efficacy and carry risks of analgesic‑related dependence, whereas hallucinogenic agents were reported by some patients to have marked prophylactic effects even when used only one to three times per year and sometimes at sub‑hallucinogenic doses. The investigators stress that this survey cannot determine true efficacy and call for randomised controlled trials with well‑titrated, laboratory‑produced medications to provide definitive evidence. Legal and public‑health concerns are also discussed. The authors point out that patients may underestimate judicial risks and the potential for illicit drug purchases to fund organised crime; at the time of the survey Italian law remained restrictive and cannabinoids were not decriminalised. Key limitations acknowledged include reliance on self‑reported diagnoses not independently verified and the inability of the study design to yield efficacy estimates. The paper concludes by noting that some patients with intractable CH are choosing illicit treatments based on peer or Internet recommendations and that this trend raises unresolved questions about physician–patient interactions and the need for improved counselling when patients consider or use illicit substances for CH.