Obsessive-compulsive disorder in primary tic disorders and Gilles de la Tourette syndrome.

This chapter provides a review of obsessive-compulsive disorder (OCD), as it manifests in primary tic disorders and Gilles de la Tourette syndrome (GTS). We examine the clinical features of OCD in GTS, focusing on how these symptoms diverge from typical OCD presentations, often blending with or mimicking tics. Key pathophysiologic mechanisms are explored, with an emphasis on the neurobiologic substrates that underlie this unique OCD subtype and distinctions from tics. Finally, the chapter discusses therapeutic approaches specifically adapted for this population, highlighting both established and emerging treatments. This chapter aims to deepen understanding of the complex interplay between OCD and GTS, offering insights into more effective clinical management and therapeutic strategies for affected individuals.