I would never use drugs but if therapists were legally able to do it (although I don't think they should be able to do so - or just get rid of controlling stuff and make everything available to everyone who wants to buy it and ingest it) in general- I would not be bothered that the therapist could for others. If they tried to push them on me I would have a large problem with that.
I pretty much believe a trained monkey could give out/prescribe drugs if not for the strong medical lobby that keeps the power with them.