Neuropsychology of obsessive-compulsive disorder

Introduction Neuropsychological research has emerged as a valuable tool in shaping our understanding of the pathophysiology of obsessive-compulsive disorder (OCD). Below, we review neuropsychological findings in OCD and their relationship to current neuroanatomical models of the disorder. This review extends previous ones that we have written, together with our colleagues, on the same and related topics (Anderson et al.,2004; Savage, 1998). The cortico-striatal model of OCD Structural and functional neuroimaging studies implicate the striatum, orbitofrontal cortex (OFC) and anterior cingulate (ACC) in the pathophysiology of OCD. Studies using positron emission tomography (PET) and single photon emission computed tomography (SPECT) in OCD have found increased regional brain activity within the OFC, ACC (Baxter et al., 1987, 1988, 1992; Machlin et al., 1991; Nordahl et al., 1989; Rubin et al., 1992; Swedo et al., 1989) and the striatum (specifically, caudate nucleus; Baxter et al., 1987, 1988). Studies employing PET (Rauch et al., 1994) and functional magnetic resonance imaging (fMRI) studies (Adler et al., 2000; Breiter et al., 1996) have revealed increased brain activity or activation within anterior/lateral OFC, ACC, as well as caudate nucleus when OCD-related obsessions were provoked using OCD-related stimuli.