A survey of 256 Icelandic mental health professionals—psychiatrists, general practitioners, and psychologists—found that most had little or no knowledge of psychedelic substances and expressed negative attitudes toward treatment with psilocybin mushrooms, though they supported ongoing scientific research. Around half of psychiatrists had received patient questions about psychedelic treatment, compared to 14.6% of general practitioners and 17.5% of psychologists. Respondents believed psilocybin treatment should be prescribed and provided by psychiatrists in specialized clinics or hospital psychiatric units. Scientific articles, colleague discussions, and media most influenced their attitudes. Most wanted further education on psychedelics, feeling the time has not yet come for their use in treating mental disorders in Iceland.
Psilocybin, a hallucinogen, shows promise as a treatment for treatment-resistant depression (TRD). A single 25 mg oral dose, accompanied by 5-8 hours of psychological support, produces antidepressant effects. Common side effects include headache, nausea, fatigue, and insomnia. A systematic review found significant antidepressant efficacy in certain groups, and a double-blind randomized study reported effects comparable to the SSRI escitalopram. In a phase 2 COMPASS Pathways study, about one third of participants experienced rapid response and remission within three weeks of psilocybin-COMP360 treatment. Recent studies indicate psilocybin significantly reduces depressive symptom severity and is generally well tolerated, though further research is needed before licensing for TRD.