False science or not false science, and psychology does not diagnose schizophrenia. If the patient has spoken about glucose, then all that psychology can do is advise him to visit a psychiatrist or a narcologist.
Here's the diagnosis of crying, like hearing voices to feel special and (or) attracting attention to yourself - with this you can also work in psychology. But only after psychiatry and narcology will confirm that he is still lying, and not on their part passes)))