How does a psychiatrist or pscyhologist test for schizophrenia?

Signs & symptoms. There's no test for schizophrenia, although some psychological testing (ie, pencil & paper tests) can lend evidence for or against the diagnosis. Schizophrenia is diagnosed clinically, by signs and symptoms. These include a chronic pattern of social withdrawal, delusions and/or hallucinations, and flat (or inappropriate) emotional expression. There is no cure, but treatment helps hugely.