What products/services will experience growth if psychedelics take off?

Are you referring to companies like MindMed? If so, I'm not sure what would increase with them directly. They are medically oriented, so it's not supposed to be recreational and has stricter requirements than medical marijuana - it's to be used under medical supervision/guidance.

I would think we would be most likely to see a decrease in drug companies that currently provide antidepressants if psilocybin works as well as the evidence suggests so far.

That said, we could see indirect increases in specific sectors based on the mindset changes that people might experience. So people might feel more like living in the moment and travel more or do other recreational things.