chapter 1 Autism Spectrum Disorders: Phenotype and Diagnosis -- chapter 2 Past and Future Perspectives on Autism Epidemiology -- chapter 3 Genetic Basis of Autism -- chapter 4 Finding Genes in Spite of Heterogeneity: Endophenotypes, QTL Mapping, and Expression Profiling in Autism -- chapter 5 A Mixed Epigenetic and Genetic and Mixed De Novoand Inherited Model for Autism -- chapter 6 Neurobiology of Related Disorders: Fragile X Syndrome -- chapter 7 Fear and Anxiety Pathways -- chapter 8 Cerebellar Networks and Autism: An Anatomical Hypothesis -- chapter 9 Language in Autism -- chapter 10 Prefrontal Cortex -- chapter 11 The Social Brain, Amygdala, and Autism -- chapter 12 The Thalamus and Neuromodulatory Systems -- chapter 13 Modeling Features of Autism in Animals / chapter 14 Neuroanatomical and Neurochemical Studies of the Autistic Brain: Current Thought and Future Directions / chapter 15 The Social Brain in Autism: Perspectives from Neuropsychology and Neuroimaging / chapter 16 Structural Neuroimaging / chapter 17 Neuropsychology and Neurophysiology of Autism Spectrum Disorders / chapter 18 Pharmacological Treatments / chapter 19 Behavioral, Educational, and Developmental Treatments for Autism / chapter 20 The Costs of Autism