Who is Joey Pigza from the novel, Joey Pigza Swallowed the Key?

Joey Pigza is a young man with a hyperactivity disorder. Joey knows he is a good person, but cannot seem to help himself from getting into trouble. Joey's father and mother abandon him early in life, and he is forced to live with an abusive grandmother who gives him little support. Years later, his mother returns, only to throw his life into confusion and disorder.