Brain Regions and Neuropsychological Deficits in Obsessive-Compulsive Disorder

Neurobiological factors had been shown to play an important role in the emergence of obsessive-compulsive disorder by the information obtained from the methods developed over the years. According to the neuropsychological perspective, the defects had been detected mainly in executive functions, in attention, memory, visual-spatial functions; and abnormalities had been described in the frontal lobe, cingulate cortex, basal ganglia, and thalamus regions of the patients with obsessive-compulsive disorder. The main and the most repeated abnormalities in patients with obsessive-compulsive disorder are dysfunctions in executive function and visual memory. Dysfunctions of the inhibitory processes associated with the dominant frontal area lead to an insufficiency on the inhibition of verbal functions. Excessive activation of the orbitofrontal cortex that mediate the behavioral response suppression function in obsessive-compulsive disorder demonstrated by functional imaging techniques. Repeated-resistant behaviors (eg: compulsions) are composed by the deteriorations of the inhibitions of motor or cognitive programs in basal ganglions provided through cycles of frontal lobe. The findings of clinical observations in patients with obsessive-compulsive disorder could be considered as a reflection of excessive work in 'error detection system' which is the cause of the thoughts that something goes wrong and efforts to achieve perfection. As neurobiological, this finding is observed as excessive activity in orbitofrontal cortex and anterior cingulate cortex representing the ability of humans to provide and detect errors. It is is expected to develop the vehicles that are more sensitive to the characteristics of cognitive deficits in obsessive-compulsive disorder. In addition to the neuropsychological tests, using electrophysiological and advanced functional imaging techniques will put forward a better underlying the physiopathology of this disorder in order to show the more distinctive structural and functional impairments