The Primer on Autism Spectrum Disorder provides a quick yet comprehensive overview of clinically-relevant topics related to autism spectrum disorder (ASD) for the medical or mental health student, trainee, or recent graduate who seeks efficient learning. Chapters are designed to give an overview of a topic area in real time while on a rotation; while studying for professional board examinations in primary care, pediatrics, neurology or psychiatry; or even during preparation for a presentation or discussion scheduled to occur the next day. The sections include Background and Diagnostic Assessment, Etiology, Treatment, and Other Care Delivery Services and Perspectives, with each chapter written by an internationally recognized expert in the field. The chapters on diagnosis and treatment are written from a practical "how to" perspective. Those on etiology are written with the clinician in mind. These clinically-focused chapters include one or more vignettes that present simulated patient cases designed to highlight teaching points related to each chapter's content area. The book ends with a chapter written by family members of individuals with ASD and another written by an adult with ASD that illustrate the human impact these disorders have on day-to-day lives, hopes, and dreams. At the end of each chapter, "Key Points" for summarizing the intended take home messages of each author/authors are listed.