> This is where pseudoscience comes from.

I disagree, if it stopped it stopped. It could be from something else, but his LSD intake is the most likely candidate. It would become pseudoscience if he or she would claim that this will work for everyone.

Also, don't forget that science can make a similar flaw. Just because a drug works on average, doesn't mean that it will work for you or that it won't have any negative side effects. Human variation can be quite big with certain things.