This document discusses behavior therapy for teenagers and young adults with autism spectrum disorders. It begins by providing credentials for the author, Daniel C. Marston, who has over 15 years of experience providing behavioral health services to individuals with neurological disorders. It then discusses autism spectrum disorders and the diagnostic criteria for autism, Asperger's disorder, and pervasive developmental disorder based on the DSM-IV. The document discusses empirically-based practice in psychology and core principles. It covers neurological and psychological aspects and theories of autism based on research. Finally, it discusses psychological effects of autism, including personality traits, quality of life, gender differences, and anxiety/mood problems in adolescents with autism.