Autism spectrum disorder (ASD) is a range of complex neurodevelopment disorders, characterized by social impairments, communication difficulties, and restricted, repetitive, and stereotyped patterns of behavior. Autistic disorder, sometimes called autism or classical ASD, is the most severe form of ASD, while other conditions along the spectrum include a milder form known as Asperger syndrome, and childhood disintegrative disorder and pervasive developmental disorder not otherwise specified (usually referred to as PDD-NOS). People with ASD often have issues with social, emotional, and communication skills. They might repeat certain behaviors and might not be comfortable with change occurring in their daily activities. Many people with ASD also have different ways of learning, paying attention, or reacting to things. There is currently no cure for ASD. However, research shows that early intervention treatment services can improve a child’s development.