I really know very little. I do know the research is early and ongoing. It is suspected that they may be the problem with with antidepressants (and other drugs) for some people, strongly suspected by some, though the actual mechanism isn't known. If it's true, then someone would likely repsond poorly to all 5HT2 antagonists if one responded badly to one. Of course, some drugs are stronger antangoists than others; that would be a factor in how well or poorly someone responded to different 5HT2 antagonists.