Everyone in the study receive a dosage (adjusted for the person's weight) that I think amounted roughly to either one gram (one group) or .5 gram (a second group). Or placebo (third group). So it wasn't a matter of greater or lesser doses, just that the level of psychedelic experience that people had with roughly equal doses was not correlated with the amount of relief they got.
Another interesting finding was that people with chronic CH did better in the study than people with episodic CH. Which seems weird overall, but even more weird considering the relatively small doses.
(As you may know, the study did not show a statistically significant difference in relief between people who got psilo and people who got placebo. The numbers were slightly better for people who got psilo, but not at a level of statistical significance. Dr. Schindler has said that the number of participants in the study was too small to get valid results from it.)
(I suppose I might cough up the $12 or something that is costs to read the whole thing, because I have about 200 questions. One of those, probably not explained or explainable, is that the standard was the number of attacks after receiving the dose (psilo or placebo). But if people were getting slapbacks from the psilo, which you have to imagine some were, that would be more attacks than the others would get from a placebo.)