Health and Medical Services Center, Shiga University, 1-1-1, Baba, Hikone, Shiga 522-8522, Japan.
Department of Neurodevelopmental Psychiatry, Habilitation and Rehabilitation, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Psychiatry Res Neuroimaging. 2019 Mar 30;285:40-46. doi: 10.1016/j.pscychresns.2019.01.012. Epub 2019 Jan 30.
Obsessive-compulsive (OC) traits such as intrusive worrisome ideas or excessive concerns for threats are frequent in general population (5%-13%). However, the structural neural correlates of the sub-clinical OC traits remain largely unknown. Based on the data of obsessive-compulsive disorder (OCD), we hypothesized that the subcortical and cortical structures, constituting the cortico-striatal-thalamo-cortical circuit (CSTC) and the limbic system, could be associated with OC traits. Here we conducted voxel-based morphometry (VBM) in order to investigate fine grained volume changes of these structures in 49 non-clinical subjects. Analysis of structural covariances of these structures was also conducted. We identified volume changes associated with OC traits in the left putamen and the left amygdala. The results of structural covariance analysis revealed increased covariances in relation to the heightened OC traits between the left putamen to bilateral medial prefrontal cortex and to the left cerebellum, and between the left globus pallidus to the bilateral anterior cingulate cortices. The present finding of volume changes of the corticostriatal-limbic structures may reflect neuroplasticity associated with OC traits. Since the abnormality of these structures were also observed in the clinical OCD, the subclinical subjects with OC traits shared "neuronal obsessive traits" that might precondition OCD at the network level.
强迫观念和强迫行为（OCD）是一类以反复出现的强迫思维和强迫行为为主要临床表现的精神障碍，其终生患病率为 1%~3%，且 2/3 的患者起病于青少年期。强迫观念是指反复出现的、不自主的、无意义的、闯入性的想法、表象或冲动，患者能意识到这些想法是不必要的，但却无法控制或摆脱它们。强迫行为是指为了减轻或预防强迫观念引起的焦虑或痛苦而采取的重复性行为或仪式，如反复检查、洗涤、计数、排序等。强迫障碍患者的大脑结构和功能存在异常，这些异常可能与强迫障碍的发生、发展和维持有关。
