Shared functional abnormalities within somatosensory cortex in obsessive-compulsive disorder and anxiety disorders: A comparative meta-analysis.

BACKGROUNDS: Obsessive-compulsive disorder (OCD) has been consistently associated with alterations in cortico-striato-thalamo-cortical (CSTC) circuits, as demonstrated by numerous resting-state fMRI studies. However, given the high prevalence of comorbid anxiety disorders and anxiety-related traits in OCD patients, previous research has not clearly established whether these neural alterations are specific to OCD or represent shared pathophysiology with anxiety disorders (ANX). METHODS: We conducted a coordinate-based meta-analysis using Signed Differential Mapping (SDM) of whole-brain resting-state fMRI studies in OCD (n = 1429 patients, n = 1509 healthy controls). To assess whether identified alterations were OCD-specific or shared with anxiety pathophysiology, we performed comparative meta-analyses including 15 ANX studies (n = 558 patients, n = 561 healthy controls) using conjunction and contrast analyses, and examined resting-state local brain activity as indexed by ALFF, fALFF, and ReHo. RESULTS: Compared to ANX, OCD patients showed increased spontaneous activity in the left anterior cingulate cortex extending to the medial prefrontal cortex (ACC/MPFC), right globus pallidus, and left putamen, alongside decreased spontaneous activity in the left middle frontal gyrus. Both disorders shared decreased spontaneous activity in the left postcentral gyrus. However, this meta-analysis did not identify significant differences in amygdala activity in within-group or between-group comparisons, nor in conjunction analyses. CONCLUSIONS: Overall, this meta-analysis reveals shared reductions in spontaneous activity in the left postcentral gyrus across OCD and ANX, suggesting a potential role for the somatosensory cortex in transdiagnostic emotional processing.