Chapter 9.Neurodevelopmental Disorders

In this chapter, we consider the DSM-5 diagnostic class of neurodevelopmental disorders (American Psychiatric Association 2013). As the name implies, disorders within this class represent impairments in a broad range of cognitive, motor, or sensory functions that typically change dynamically across developmental stages. These conditions are characterized by symptoms that are acquired or inherited and that demonstrate divergence from an expected trajectory of skill acquisition over time. Etiologies for disorders within this class are highly heterogeneous. Indeed, the nature of these developmental effects is such that definitions of pathology may encompass individuals falling in the lower tail of population-wide dimensional traits, as well as individuals affected by more specific pathophysiological processes. Regardless of cause, it is important to approach disorders in this category with a comprehensive evaluation of a number of cognitive functions; careful consideration of genetic, familial, and environmental risk factors; and contextualization within a developmental framework. As with other diagnostic classes, impairments in this group of disorders must demonstrate significant impact on adaptive functioning, generally manifesting in learning or work environments.