A person who professionally involved in messing with other people's minds. The basic idea for the professional psychologist is to unwrap the inner tensions that might have caused a serious mental dysfunction. The psychologist prime work tool is the conversation( medication and strap jackets are more something for alienists and psychiatrists).
This kind of probing into more or less lunatic minds might lead to the discovery that all ravaging lunacy might not be pure imagination. Some of it might be based on facts that an ordinary mind just can't handle.