If you put all the existing evidence together – which is much more than just those two studies – even with the risks of bias, it really is overwhelming. See, for example, Fig. 2 in our policy paper, based on a paper by Schindler et al. https://www.preventsuffering.org/wp-content/uploads/2020/11/Legalising-Access-to-Psilocybin-for-Cluster-Headaches-Policy-Paper.pdf, and also some of the patient testimonials. The usual standards for determining the effectiveness of new medications are understandably more rigorous than for other kinds of situations, but in the case of cluster headaches, the huge number of patient reports claiming the efficacy of psychedelics (while other substances like cannabis are generally ineffective), including chronic cluster headaches that end after a few doses of psychedelics, essentially excludes the possibility that there is no causal relationship. And the extreme pain means that patients have the right to access them even if there were any doubts. We’re actually preparing a case series for submission, with a Zurich-based neurologist who can legally prescribe psychedelics, on the results obtained with her patients.
If you put all the existing evidence together – which is much more than just those two studies – even with the risks of bias, it really is overwhelming. See, for example, Fig. 2 in our policy paper, based on a paper by Schindler et al. https://www.preventsuffering.org/wp-content/uploads/2020/11/Legalising-Access-to-Psilocybin-for-Cluster-Headaches-Policy-Paper.pdf, and also some of the patient testimonials. The usual standards for determining the effectiveness of new medications are understandably more rigorous than for other kinds of situations, but in the case of cluster headaches, the huge number of patient reports claiming the efficacy of psychedelics (while other substances like cannabis are generally ineffective), including chronic cluster headaches that end after a few doses of psychedelics, essentially excludes the possibility that there is no causal relationship. And the extreme pain means that patients have the right to access them even if there were any doubts. We’re actually preparing a case series for submission, with a Zurich-based neurologist who can legally prescribe psychedelics, on the results obtained with her patients.