Autism is a developmental disorder that affects communication and behavior and appears during early childhood. It is characterized by difficulties with social interaction and verbal/nonverbal communication, as well as repetitive behaviors. Signs of autism include lack of or delayed speech, poor eye contact, repetitive movements, unusual play, and sometimes aggression. While the causes are unknown, autism is diagnosed through developmental and social interaction testing. Treatment involves medication to treat associated symptoms, as well as therapies like occupational therapy, speech therapy, and behavioral techniques.