All neurodevelopmental disorders which include autism and related conditions fall under the category of autism spectrum disorder. Problems in social interaction and repetitive patterns of behavior are the two main symptoms of autism spectrum disorder. There is no specific cause associated with these disorders, but risk factors include neuroanatomical abnormalities, genetic conditions like fragile X syndrome, prenatal and perinatal risk factors like maternal gestational diabetes and a family history of similar condition. The assessment of behavior is the primary way to diagnose autism spectrum disorders. Autism Diagnostic Interview-Revised (ADI-R), Childhood Autism Rating Scale (CARS), and Autism Diagnostic Observation Schedule (ADOS) are some of the commonly used diagnostic measurements. Medications include atypical antipsychotic drugs and anticonvulsants. Some alternative therapies and interventions, including CEASE therapy and vaccine detoxing are also used to treat autism spectrum disorders. This book unravels the recent studies in the field of autism spectrum disorders. Some of the diverse topics covered herein address the varied aspects of assessment and treatment of such disorders. This book is a complete source of knowledge on the present status of these disorders.