Opinion Mining of Erowid's Experience Reports on LSD and Psilocybin-Containing Mushrooms.
Ahmed Al-Imam, Riccardo Lora, Marek A Motyka, Erica Marletta, Michele Vezzaro, Jerzy Moczko, Manal Younus, Michal Michalak
Drug safety May 1, 2025 DOI: 10.1007/s40264-025-01530-z (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational study using natural language processing Peer reviewed |
|---|---|
| Sample size | 2,188 |
| Population | Users of the Erowid forum who reported experiences with psilocybin-containing mushrooms or LSD |
| Topics | LSD Psilocybin |
| Keywords | Consciousness research Altered states Psychedelics Drug effects |
| Citations | 1 |
| Key findings | Psilocybin mushroom reports emphasize introspection and time dilation, while LSD reports highlight cognitive disturbances and memory issues, with sentiment analysis showing model-dependent polarity differences. |
Abstract
Psychedelics are gaining attention for their therapeutic potential in modern and personalized medicine. Online forums such as Erowid provide valuable user insights, but analyses of these experiences using natural language processing (NLP) remain scarce. This study aims to utilize NLP, including sentiment and lexicon analysis, to examine user-generated experience reports on psilocybin-containing mushrooms and LSD from the Erowid forum. Data from 2188 Erowid users (1161 psilocybin mushrooms and 1027 LSD) was collected via automated web scraping with XPath, CSS selectors, and Selenium WebDriver. The dataset included report titles, substances, and demographics. Sentiment analysis utilized BERT, RoBERTa, and VADER models. Preprocessing involved tokenization, lemmatization, part-of-speech tagging, and stop-word filtering. Lexicon analysis identified themes through recurring n-grams, visualized using Python. User demographics revealed comparable ages for psilocybin mushrooms (23.8 ± 0.9 years) and LSD users (20.0 ± 0.6 years), with a predominance of male users. The BERT model predominantly labeled experiences as negative (unfavorable), particularly for mushroom users (p = 0.001). VADER indicated more positive experiences for mushroom users (p < 0.001), while RoBERTa mainly classified experiences as negative or neutral. Significant gender differences were found only with VADER, where more male users expressed positive opinions about psilocybin mushrooms (74.09% versus 65.52%, p < 0.021). The VADER model yielded more polarized results, whereas RoBERTa's cautious classifications indicate its suitability for analyzing lengthy and complex psychedelic reports. Further, RoBERTa outperformed other transformer-based models, achieving the highest accuracy. Lexicon analysis revealed emotional, sensory, and temporal themes, with psilocybin reports emphasizing introspection and time dilation phenomenon, while LSD reports highlighted memory issues and cognitive disorientation. Sentiment analysis showed that VADER produced more polarized results, while RoBERTa offered cautious classifications with the highest accuracy. Lexicon analysis revealed shared themes, with mushroom reports focusing on introspection and time dilation perception, while those of LSD emphasized cognitive disturbances. This study highlights the value of these analyses in understanding psychedelic experiences, informing harm reduction, and guiding policy-making.
Comparable studies
Other observational and cohort studies on LSD, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Increased Global Functional Connectivity Correlates with LSD-Induced Ego Dissolution. Human participants | 2016 | Observational cohort | |
| Increased spontaneous MEG signal diversity for psychoactive doses of ketamine, LSD and psilocybin Humans | 2017 | Observational study | |
| Classic psychedelic use is associated with reduced psychological distress and suicidality in the United States adult population. USA adult respondents from the National Survey on Drug Use and Health (2008-2012) | 2015 | Observational cohort | n = 190,000 |
| Psychedelics not linked to mental health problems or suicidal behavior: A population study Randomly selected United States adults | 2015 | Observational cohort | n = 135,095 |
| Whole-Brain Multimodal Neuroimaging Model Using Serotonin Receptor Maps Explains Non-linear Functional Effects of LSD. Healthy human participants | 2018 | Observational study with computational modeling |
Citations in the library
Cited by 2
Cites 34
- Adverse effects of psychedelics: From anecdotes and misinformation to systematic science. Journal of Psychopharmacology February 2, 2022
- Ketamine Psychedelic Therapy (KPT): A Review of the Results of Ten Years of Research Journal of Psychoactive Drugs June 1, 1997
- Adverse events in clinical treatments with serotonergic psychedelics and MDMA: A mixed-methods systematic review Journal of Psychopharmacology August 26, 2022
- Extended difficulties following the use of psychedelic drugs: A mixed methods study PLoS One October 24, 2023
- Residential Psychedelic (LSD) Therapy for the Narcotic Addict Archives of General Psychiatry June 1, 1973
and 29 more in the library