Problem is, many otherwise good doctors are not very knowledgeable about illicit drugs, particularly those that are comparatively rare/aren't a public health crisis (LSD, while popular, is kinda niche compared to meth and opioids).

A big chunk of the time you're just going to get "Don't use drugs", simply because they don't have much else to say about it, and don't want you taking risks based on something they've said. Doesn't mean don't ask*, but know you may not get useful harm reduction information from Dr. F. Practitioner.

*That said there IS a risk that such a question can paint you as a potential drug seeker, and so create barriers to care if someone decides to add that to your chart when you were just trying to minimize risk.