In general, you can trust a psychiatrist to be real as these are medical doctors and governments are usually hot on policing those. Usually.
Medicine and medical tests are the province of medical doctors. Of the mental health practitioners, only psychiatrists, medical doctors who specialise in mental health, do these.
Psychologists, therapists, counsellors and so on don't them
So, if you're asked for a urine test or told to buy vitamins or whatever, and you are not talking to a psychiatrist - run!
Governments can be lax about who's calling themselves a psychologist. But universities will out fakes who claim to be alumni, although it can take a while.
Everyone knows about the fakes and so we're careful to state on our business cards and websites exactly what we studied and where.
If you don't see the name of a university, run.
If you don't see the exact qualification, run.
Money. Crooks are usually more expensive than the real deal.