Investigation of self-treatment with lysergic acid diethylamide and psilocybin mushrooms: Findings from the Global Drug Survey 2020

Psychedelics such as LSD and psilocybin have a long history of use for healing, and recent decades have seen a resurgence of clinical research and rising public interest in their therapeutic potential. Kopra and colleagues note that much contemporary use nevertheless occurs outside formal clinical settings — in informal, underground, retreat or community contexts — and that outcomes observed in tightly controlled clinical trials may not generalise to these naturalistic self-administered practices. The authors also highlight that users' mindset and environment ('set and setting') and the presence or absence of interpersonal support are central determinants of psychedelic experiences and their risks and benefits. This study uses data from the Global Drug Survey (GDS) 2020 to examine patterns and outcomes of self-treatment with LSD or psilocybin-containing mushrooms. The investigation aims to describe how people self-treat (including dose-intensity proxies and whether advice was sought), to report self-rated positive and negative outcomes across multiple domains, and to identify predictors of those outcomes with respect to demographics, treatment patterns and the condition or problem treated. The analysis focuses specifically on respondents who indicated either LSD or psilocybin mushrooms as the substance they found most useful for self-treatment within the past year.

Data come from the Global Drug Survey 2020, an annual, anonymous, encrypted online survey open to people aged 16 or older and available in 16 languages; data were collected between 7 November 2019 and 5 February 2020. Multi‑institutional ethical approvals were obtained and participants could skip questions. Access to the relevant GDS sections (demographics and psychedelics) was gained under a data sharing agreement. As a non-probability self-selected sample, the GDS is not representative of the general population but captures a large number of people who use substances in varied contexts. Respondents who reported self-treating a diagnosed condition or a specific worry with psychedelics in the past 12 months were directed to an optional section. From those who had used several substances, participants were asked to select the single substance they had found most useful; this study was restricted to respondents who chose either LSD or psilocybin mushrooms. Participants selected the main condition they were trying to treat from a list (originally 19 categories, reduced to 13 for analysis due to small counts), reported the number of self-treatment occasions in the past year, rated the intensity of the psychedelic experience on a five-level item (from ‘intense psychedelic experience’ to ‘no experience or effects’), and indicated whether they had sought advice beforehand and the source(s) of that advice. Outcomes were measured with two investigator-constructed scales. The primary scale comprised 17 self-treatment outcome items covering well-being, psychiatric symptoms, social–emotional skills and health behaviours; each item was rated on a seven-point scale from −3 (strong negative consequences) to +3 (strongly positive consequences), with N/A available. Internal consistency for the 17 items was high (Cronbach's α = 0.91), but the authors acknowledge the scale was not psychometrically validated beyond that. The second instrument was a 10-item negative outcome checklist; respondents who reported any negative effects rated each item as none, mild, moderate or severe. Because the negative items were ordinal and to create a single summary measure, each negative item was dichotomised (none = 0; any severity = 1) and summed to yield a count variable from 0 to 10. Statistical analyses included descriptive statistics for demographics, patterns of self‑treatment and item-level outcomes, plus multivariable models to examine predictors. The mean score across non-missing items on the 17-item scale was used as the dependent variable in an ordinary least squares regression; predictors were age (continuous), gender (Male/Female/Other), substance used (LSD/psilocybin mushrooms), seeking advice (Yes/No), intensity of experience (5 categories) and condition treated (13 categories). Duration outcomes (originally 12 response categories) were collapsed into three groups (up to 7 days; 1–4 weeks; 1 month or more) and analysed with ordinal regression, with multinomial logistic regression used when proportional‑odds assumptions were violated. The count of negative outcomes was modelled using negative binomial regression to allow for overdispersion. Analyses used complete‑case approaches rather than imputation and applied a Bonferroni-style correction for multiple tests (adjusted significance threshold p = 0.002 based on 21 predictive factors). Sensitivity analyses restricted some models to respondents with fewer than five missing or N/A responses on the outcome items.

From 113,284 respondents to GDS 2020, 10,268 people (13.8%) reported self-treating a psychiatric condition or specific worry with psychedelics in the past year. Of those reporting substances used for self-treatment, 1996 respondents indicated LSD and 1368 indicated psilocybin mushrooms as the single substance they found most useful, yielding an analysis sample of N = 3364. The sample was young (mean age 25.4, SD 8.5), predominantly male (N = 2422; 72.0%) and majority white (N = 2679; 80.3%); 56.5% (N = 1899) reported a lifetime diagnosis of one or more mental health conditions. Descriptive tables and figures in the paper (not reproduced here) show patterns of treatment and item-level responses. On the 17-item outcome scale (range −3 to +3), the mean across items and respondents was 1.42, indicating mild-to-moderate self-reported improvements overall. Half the sample (N = 1573; 50.0%) rated +2 or +3 on at least nine of the items, and 94.6% had a +2 or +3 on at least one item. The highest-scoring items were insight-related and mood: 'changes in my understanding of why I feel the way I do', 'changes in mood or reduced depression', and 'changes in my understanding of my condition or how I relate to it'. Among those reporting strong positive effects on at least one item (N = 2975), most noticed effects within 24 hours (64.3%; N = 1890) and for the majority effects lasted at least four weeks (52.7%; N = 1497); 17.6% (N = 499) reported durations longer than six months. Negative outcomes were reported by 705 respondents, representing 22.5% of the 3136 participants who answered the question about any negative consequences. Among those reporting negatives, the median number of negative outcomes was 5.0 (IQR 3.0–7.0). The most commonly endorsed negative items were 'mental confusion, memory problems, or racing thoughts' and 'feeling disconnected from the world around you'. Onset of negative effects was most commonly within 24 hours (59.7%; N = 410), although 20.1% (N = 138) reported noticing at least one negative outcome more than a week later. Duration of most negative effects was 7 days or less for 54.6% (N = 370) but one month or more for 27.0% (N = 183). A minority sought emergency medical treatment: 28 respondents (4.2% of those reporting negative effects, 0.9% of the total sample) sought emergency care (25 once, 3 more than once). Multivariable analyses showed the OLS model predicting mean 17‑item outcome score was statistically significant but explained little variance (R2 = 0.06; F[21,3004] = 9.36; p < 0.001). After adjustment, self-treatment with LSD was associated with lower mean outcome scores compared with psilocybin mushrooms; having sought advice beforehand was associated with higher outcome scores. Intensity of experience had a strong omnibus effect: higher intensity (the reference being 'high intensity') was associated with higher outcome scores, and 'no experience or effects at all' was associated with the lowest scores. Condition treated also had an omnibus effect; notably, treating PTSD was associated with higher outcome scores compared to treating depression. Age and gender were not associated with the mean outcome score. Sensitivity analysis limited to respondents with fewer missing outcome responses produced comparable results. For duration outcomes, proportional-odds assumptions were violated in some models and multinomial logistic regression was used. The only consistent predictor reported for duration of negative outcomes was age: older age was associated with shorter duration of negative effects. Other predictors (gender, substance, seeking advice, intensity, and condition treated) were not associated with duration of negative outcomes in adjusted models. The authors also report that higher intensity of experience related to both greater positive outcomes and a greater number of negative outcomes, and that younger age, high intensity, and treating with LSD were associated with increased number of negative outcomes in some analyses.

Kopra and colleagues interpret the findings as showing that, in this large international self-selected sample, self-treatment with LSD or psilocybin mushrooms was generally associated with self-reported improvements across a broad range of wellbeing and symptom-related items, with effect timelines resembling those observed in clinical trials. Insight and mood-related outcomes were rated most highly, aligning with prior reports that psychedelic-facilitated personal insight and emotional breakthrough are commonly reported therapeutic processes that can contribute to sustained wellbeing. The authors emphasise that negative outcomes were not uncommon: 22.5% of respondents reported at least one adverse consequence, most commonly transient cognitive or emotional disturbances, and for a minority these persisted beyond four weeks. They note that persisting perceptual changes were reported by 8.5% of respondents but were seldom rated as severe. The study team contrast these rates with findings from contemporary clinical trials, where persisting severe adverse effects have been rare, and suggest that the lack of professional interpersonal support in self-treatment contexts may elevate some risks. Several predictors of outcomes are highlighted. Intensity of the psychedelic experience was among the strongest predictors of positive outcomes and of longer-lasting effects, which mirrors evidence from clinical dosing studies; however, higher intensity was also associated with more negative outcomes. Seeking advice prior to self-treatment was associated with better outcomes and a trend to fewer negatives, with respondents mainly drawing on informal sources (websites, forums, friends) rather than clinicians. Psilocybin mushrooms were associated with slightly better overall outcome scores and fewer negative outcomes than LSD, though the effect size was small. Treating PTSD was associated with higher outcome scores relative to depression, but the authors caution that differences between conditions may reflect baseline severity, comorbidity and sample-size limitations. Younger age was linked to a higher number and longer duration of negative outcomes, which the authors suggest could reflect riskier patterns of use among younger people. The authors acknowledge important limitations: the self‑selected, predominantly young, white and male sample; retrospective self-report with potential recall and expectancy biases; the non-randomised observational design and the instruction to report on the substance each respondent deemed most useful (which can bias comparisons between substances and intensities); lack of validated symptom measures and no baseline morbidity data; modest variance explained by models and the absence of several potentially important predictors (interpersonal support, expectations, personality, exact dose, substance purity and concomitant substance use). Finally, they note that their 17-item scale, while internally consistent, was not psychometrically validated. In conclusion, the study authors propose that these findings can inform harm-reduction efforts and guide future experimental research, while recommending prospective designs and inclusion of additional predictor variables to better understand benefits and risks of self-administered psychedelic use outside clinical settings.