The Ballymena Psychiatrist

Did you hear about the Ballymena psychiatrist?
He only treats schizophrenics. It means he can send them two bills every month.
One day another Ballymena man came in. The psychiatrist treated him for an hour, and at the end of it told him that he was a schizophrenic.
'That'll be £20,'he said.
'Here's £10,' said the patient. The other fella can look after himself.'