Not in the US. It is a scheduled I substance which means it has no redeeming medical value whatsoever.
Numerous psychotherapists and researchers have enjoyed considerable success with unapproved methods. And really I should not imply that such success is limited to issues of the mind. Does laying on of hands help, twirling psychic energy, acupuncture, homeopathy, and a very long list?
I don't want to seem pedantic here; we are all familiar with the placebo effect. We are also aware of the biases which insinuate themselves into any therapist/patient relationship. Besides the placebo effect, the therapist (hopefully) believes in the therapy offered and is more likely than not to see a favorable influence. Patient, so encouraged, believes to be better, and you get this nice positive feedback summoning the patient towards improvement. The other effect you will see is the people pleasing effect--some patients are either naturally people pleaers, or become like a pet student who want to be the a+ student become so engaged with apparent improvement, they actually do...via a placebo like effect or for lack of a better term, fake it til you make it--the increased engagement with life and activity revive the pleasure pathways, and the brain bbenefits from the stimulation.
I am aware of Grob's work while I believe it was conducted in a scrupulous and most conscientious fashion, still wonder to what extent these warning I mentioned might apply. Forgive a bad pun, but the acid test of any intervention is a double blinded study where neither the observer or the subject knows whats up. They do this with any psychoactive drug before it gets to market.
With antidepressants like Prozac the separation is not that great. Placebo response is about 30%, active drug maybe 50%.
So getting back to your question--how do you administer a hallucinogen vs a placebo?
I don't discount this research whatsoever. It is just a sticky wicket to prove efficacy and with a fear of such modalities dating back to "reefer madness", you have a tough sale to get permission to do so. Things have loosened up a bit since Reagan but still a tough road to hoe. There are a couple of exceptions I can look up if interested.
Maybe the one iilegal drug with the most untapped potential for psychotherapy is something like Ecstasy. This was widely used in the bay area and other sites in the late 70' and early 80's. Therapists were reporting astonishing results with very difficult to treat patients in individual and marital counseling.
So thats the state of things--potentially promising therapies are outlawed for fear of abuse potential and adverse side effects, and in many cases, no way of assessing theirr itherapeutic impact without the non-doubleblind situation issues requiring very good study designs.
Liability issues are rampant, professional credibility will be forsaken in most quarters, why bother?? Personally, I feel the greatest potential loss is with ketamine. It has been shown to bring about VERY rapid resolution of depression yet, it can be abused, is lethal in overdose.... Much like any garden variety pain reliever. ?? I doubt any opiate could pass current FDA standards if discovered yesterday.