John Wilkes Booth was the son of prominent, wealthy actors. He, too, became an actor and was so popular, he was one of the first to have his clothes ripped off by fans. Hulton Archive/Getty hide caption
Psychology is the systematic investigation of the human mind, including behavior and cognition. It thus encompasses both normal and abnormal behavior. On the other hand, psychiatry is a branch of medicine dealing with mental illness.
Difference Between Schizophrenia and Psychosis. The Diagnostic and Statistical Manual of Mental Disorders by the American Psychiatric Association is the bible that decides what symptoms fall under what medical diagnosis.