Emotional processing and disgust sensitivity in OCD patients with and without contamination-type obsessive-compulsive symptoms – An fMRI study.

Objective: Disgust is described as a relevant emotion in OCD, particularly in contamination-type OCD, and may be involved in emotional processing in this OCD-subtype. The present study aimed to investigate the neural correlates of distress processing in contamination-type compared to non-contamination-type OCD, and the relation to disgust sensitivity. Methods: Forty-three OCD patients (n = 19 contamination-type OCD) were exposed to OCD-related, fear-related and neutral pictures. Subjective distress per stimulus was assessed by a visual analogue scale (VAS) and disgust sensitivity by the DS-R. BOLD brain activation was compared between stimuli that provoked high versus low distress at individual level. Results: In contamination- and non-contamination-type OCD, the dorsomedial prefrontal cortex, operculum, visual association cortex and caudate nucleus were activated during high versus low distress. Only in contamination-type OCD, disgust sensitivity correlated positively with the VAS scores and was associated with neural activation in the dorsomedial and visual association cortex, but not with the operculum. Conclusions: Brain activation during distress processing in OCD is similar across the OCD subtypes and related to effortful emotion regulation, processing of aversive internal states and attention. In contamination-type OCD, the distress response is related to disgust sensitivity, which correlates with brain regions associated with attention and emotion regulation.