The term "autism" comes from the Greek word "autos," meaning self, used to describe conditions of social withdrawal--or the isolated self. Around 1910, a Swiss psychiatrist first used the term to refer to certain symptoms of schizophrenia. Later, in the 1940s, physicians Leo Kanner and Hans Asperger independently used that name to describe what was a newly discovered developmental disorder whose primary symptom was social withdrawal. Today, autism is just one of three diagnoses that the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders) includes in autism spectrum disorder (ASD). While medical and neuroscience's understanding of this condition has grown exponentially, research has been fraught with controversy. Autism appears to be on the rise, depending on how you define it; and research findings suggest that its causes are more complex than previously imagined. In Scientific American's newest eBook, Understanding Autism: The Search for Answers, we've gathered the most current information on autism--how it's diagnosed, who's at risk, genetic and environmental causes, treatments and therapies. In Section 1, "Diagnosing Autism," we take a look at the symptoms, or traits, of ASD, which include three main disabilities: lack of social skills, lack of communication skills, and repetitive behaviors. Symptoms typically don't show up before two years of age, yet early recognition might help alleviate some of the developmental problems that can occur later in untreated kids. In "Early Intervention," Marissa Fessenden writes about toddlers who received speech therapy and continued to benefit years after it had stopped. Section 2, "Autistic Savants," analyzes the phenomenon of savant syndrome, in which people with disabilities, including autism, possess extraordinary mental abilities. Subsequent sections examine autism's complicated genetic and environmental causes, the nature of the condition* and current therapies. Changes to diagnostic criteria for ASD in the DSM-5 have caused understandable concern and are reviewed in two important stories by Ferris Jabr, "Redefining Autism: The New DSM Criteria" and "By the Numbers: Autism Is Not a Math Problem." Finally, in discussing available therapies, two companion pieces by Nancy Shute, "Desperate for an Autism Cure" and "Alternative Treatments: How Good Is the Evidence," take readers on a journey through the minds of parents, many of whom are desperate to help their autistic kids lead easier, productive and more fulfilling lives. While science rushes to discover better options, this eBook gives a synopsis of the state of the field--what is known and what remains unknown about this challenging condition. Click here to buy this and other Scientific American eBooks: http://books.scientificamerican.com/sa-ebooks/.