Cognitive and emotional impairments in obsessive–compulsive disorder: evidence from functional brain alterations

There is a common agreement on the existence of dysfunctional cortico-striatal–thalamus-cortical path-ways in OCD. Despite this consensus, recent studies showed that brain regions other than the CSTC loopsare needed to understand the complexity and diversity of cognitive and emotional deficits in OCD. Thisreview presents examples of research using functional neuroimaging, reporting abnormal brain pro-cesses in OCD that may underlie specific cognitive/executive (inhibitory control, cognitive flexibility,working memory), and emotional impairments (fear/defensive, disgust, guilt, shame). Studies duringresting state conditions show that OCD patients have alterations in connectivity not only within theCSTC pathways but also in more extended resting state networks, particularly the default mode networkand the fronto-parietal network. Additionally, abnormalities in brain functioning have been found inseveral cognitive and emotionally task conditions, namely: inhibitory control (e.g., CSTC loops, fronto-parietal networks, anterior cingulate); cognitive flexibility (e.g., CSTC loops, extended temporal, parietal,and occipital regions); working memory (e.g., CSTC loops, frontal parietal networks, dorsal anterior cin-gulate); fear/defensive (e.g., amygdala, additional brain regions associated with perceptual – parietal,occipital – and higher level cognitive processing – prefrontal, temporal); disgust (e.g., insula); shame(e.g., decrease activity in middle frontal gyrus and increase in frontal, limbic, temporal regions); and guilt(e.g., decrease activity anterior cingulate and increase in frontal, limbic, temporal regions). These find-ings may contribute to the understanding of OCD as both an emotional (i.e., anxiety) and cognitive (i.e.,executive control) disorder.The first author was funded by the Brazilian National Counselfor Scientific and Technological Development (CNPq) as a SpecialVisiting Researcher of the Science Without Borders program (grantnumber: 401143/2014-7). This study was partially conducted atthe Neuropsychophysiology Lab from the Psychology ResearchCentre (UID/PSI/01662/2013), University of Minho, and supportedby the Portuguese Foundation for Science and Technology andthe Portuguese Ministry of Science, Technology and HigherEducation through national funds and co-financed by FEDERthrough COMPETE2020 under the PT2020 Partnership Agreement(POCI-01-0145- FEDER-007653). This work was also supportedby the Portuguese Foundation for Science and Technology (FCT)and European Union (FSE-POPH) with two individual grants(SFRH/BPD/86041/2012 and SFRH/BPD/86027/2012).