OBJETIVO: Revisar as teorias e evidências das bases neurobiológicas do transtorno obsessivo-compulsivo e da síndrome de Tourette. FONTES DOS DADOS: Revisão dos estudos que investigam a neuroanatomia, neuroimagem, genética e imunologia desses transtornos. SÍNTESE DOS DADOS: Os comportamentos ritualísticos e pensamentos repetitivos têm sido cada vez mais estudados em nosso meio. As definições dessas entidades formam um continuum espectral de sintomas com prevalência significativa na população. CONCLUSÕES: Os avanços das neurociências possibilitaram a exploração dos aspectos genéticos do sistema nervoso central e seu funcionamento, fornecendo novas perspectivas para o tratamento de pacientes com transtorno obsessivo-compulsivo e síndrome de Tourette.

OBJECTIVE: To describe and discuss evidence-based articles on the neurobiology of obsessive-compulsive disorder and Tourette syndrome. SOURCES OF DATA: A review of the most relevant papers on the phenomenology, neuroanatomy, neuroimaging, genetic and immunological aspects of these two disorders was performed. SUMMARY OF THE FINDINGS: Ritualistic behaviors and repetitive thoughts have been extensively studied in the last years. The definitions of obsessive-compulsive disorder and Tourette syndrome emphasize the existence of a continuum of symptoms, with high prevalence in the general population. Neurobiological findings have implicated genetic and immunological factors in the etiology of these two disorders. CONCLUSIONS: Advances in neuroscience triggered genetic and immunological research studies, allowing new perspectives on the treatment of obsessive-compulsive disorder and Tourette syndrome patients.

Obsessive-compulsive disorder (OCD) has a bimodal age of onset and a range of treatment outcomes. Although most of the studies carried out so far have considered childhood and adult forms of OCD as the same disorder, more recent data have suggested that OCD children, as well as adults with an early onset of their obsessive-compulsive symptoms, may represent a distinct subgroup. This review briefly summarizes the most common clinical characteristics of the OCD presentation in children and adolescents, shows data reinforcing the idea that age of onset may be an important distinguishing feature and discusses the importance of a systematic assessment of age of onset for identifying more homogeneous subgroups of OCD patients.