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.
Assessment is more than testing. Assessment is more than testing. Psychological testing (e.g., an intelligence test, personality test, or mental health test) occurs as part of the process of psychological assessment. Thus, the results of a psychological test are rarely used on their own.