Autistic disorder

This chapter identifies the biological underpinnings, phenomenology, assessment, and medical treatment of autism, a complex neurodevelopmental disorder. Basic science has made great strides in identifying the brain pathology of autism at various levels of scrutiny. This chapter reviews genetic, molecular, histological, anatomical, and epidemiological levels of the disorder. In addition, new assessment technologies have come on line to provide greater clarity in what collection of observations should be called autism and what would not. A more uniform approach to classification and diagnosis will facilitate a better understanding of treatment trial outcomes. Although interventions that alter the pathophysiological processes that are being identified are yet to be formulated, approaches to treatment that fail to take into account the scientific evidence of the causes of autism can and should be avoided. The chapter describes an orientation to autism from the perspective of the scientific literature to provide a foundation for clinical decision making for the practitioner.