A case report describes a single patient’s history, treatment and outcome in detail. A case series does the same for a handful of patients. Case reports are often the first sign of something new, such as an unexpected side effect or interaction.
They appear throughout psychedelic research. A 2022 case report followed one person with treatment-resistant OCD for a year after a single psilocybin session (Kelmendi et al., 2022); a later randomized trial from the same team was needed to test the idea (Kelmendi et al., 2026 preprint). A 2014 report described one person’s own psilocybin use for OCD, and its author did not endorse it (Wilcox, 2014).
Case reports sit low in the evidence ranking because there is no comparison and the case may be unusual or selectively reported. What happened to one person can’t tell anyone what would happen to them. Interactions and harms first seen in case reports, such as those involving antidepressants, still need wider study.
Sources
- Kelmendi et al., Heliyon, 2022
- Wilcox, Journal of Psychoactive Drugs, 2014
- Kelmendi et al., PsyArXiv preprint, 2026
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