Repetitive Behavior in Neurodevelopmental Disorders: Clinical and Translational Findings.

Repetitive behavior refers to a highly heterogeneous set of responses associated with a wide range of conditions, including normative development. Treatment studies for aberrant repetitive behavior are limited although one promising approach involves conceptualizing such behavior as a generalized inflexibility or lack of variability in responding. Relatively little is known about the neurobiological mechanisms that mediate the development and expression of repetitive behavior, information critical to the design of effective pharmacotherapies, early interventions, and prevention strategies. We will review clinical findings in repetitive behavior as well as findings from animal models highlighting environmental factors and the role of cortical-basal ganglia circuitry in mediating the development and expression of these behaviors. Findings from animal models have included identification of a specific neural pathway important in mediating repetitive behavior. Moreover, pharmacological studies that support the importance of this pathway have led to the identification of novel potential therapeutic targets. Expanding the evidence base for environmental enrichment-derived interventions and focusing on generalized variability in responding will aid in addressing the broader problem of rigidity or inflexibility.