Neuroimaging the various symptom dimensions of obsessive-compulsive disorder

Introduction: Following consensus on fronto-striato-thalamo-frontal dysfunction as the neuronal basis of obsessive-compulsive disorder, and increasing sub-classification of this clinical picture, neurobiological differentiation of the various obsessive symptoms is also attracting interest in neuroimaging research. Method: Original papers studying the neurobiological correlates of the various dimensions of obsessive-compulsive disorder were listed by a systematic literature search. Results: The "washing" factor seems to involve particular brain structures dealing with emotional control (mainly the orbito-frontal cortex (OFC), anterior cingulate cortex (ACC), amygdala and insula), but the predominant areas in the "forbidden thoughts" factor are cognitive control brain regions (mainly basal ganglia and ACC), and in hoarding obsessions and compulsions they are decision-making areas (mainly ventro-medial parts of the OFC and dorso-lateral prefrontal cortex (DLPFC)). Discussion: The results underline the neurobiological heterogeneity of the obsessive-compulsive disorder clinical picture, pointing the way for future research approaches.