Shape analysis of subcortical structures in obsessive‐compulsive disorder and the relationship with comorbid anxiety, depression, and medication use: A meta‐analysis by the OCD Brain Imaging Consortium

Abstract

Objective Neuroimaging studies of obsessive‐compulsive disorder (OCD) patients have highlighted the important role of deep gray matter structures. Less work has however focused on subcortical shape in OCD patients. Methods Here we pooled brain MRI scans from 412 OCD patients and 368 controls to perform a meta‐analysis utilizing the ENIGMA‐Shape protocol. In addition, we investigated modulating effects of medication status, comorbid anxiety or depression, and disease duration on subcortical shape. Results There was no significant difference in shape thickness or surface area between OCD patients and healthy controls. For the subgroup analyses, OCD patients with comorbid depression or anxiety had lower thickness of the hippocampus and caudate nucleus and higher thickness of the putamen and pallidum compared to controls. OCD patients with comorbid depression had lower shape surface area in the thalamus, caudate nucleus, putamen, hippocampus, and nucleus accumbens and higher shape surface area in the pallidum. OCD patients with comorbid anxiety had lower shape surface area in the putamen and the left caudate nucleus and higher shape surface area in the pallidum and the right caudate nucleus. Further, OCD patients on medication had lower shape thickness of the putamen, thalamus, and hippocampus and higher thickness of the pallidum and caudate nucleus, as well as lower shape surface area in the hippocampus and amygdala and higher surface area in the putamen, pallidum, and caudate nucleus compared to controls. There were no significant differences between OCD patients without co‐morbid anxiety and/or depression and healthy controls on shape measures. In addition, there were also no significant differences between OCD patients not using medication and healthy controls. Conclusions The findings here are partly consistent with prior work on brain volumes in OCD, insofar as they emphasize that alterations in subcortical brain morphology are associated with comorbidity and medication status. Further work is needed to understand the biological processes contributing to subcortical shape.

Exploring the relationship between context and obsessions in individuals with obsessive-compulsive disorder symptoms: a narrative review

“…Based on accumulating evidence for alterations in context processing in OCD, it is likely that changes in the network may also be evident in OCD, and contribute to the clinical picture of such patients. Indeed, there is evidence that hippocampal volume may be altered in OCD ( 82 – 85 ). Interestingly, reduced hippocampal volume has been shown in individuals who score high on ordering and checking symptoms ( 82 ).…”

“…This is evident in the limited ability of individuals with OCD to adapt their behavior to changing contextual information ( 57 , 69 ), leading to a reduction in adaptive goal-directed behavior. Alterations in context processing in OCD may be related to changes in hippocampus volume ( 82 – 85 ). However, while the link between decontextualization and habitual behavior as well as cognitive inflexibility in OCD is plausible, so far, no studies directly explored the role of context in compulsive behavior.…”

Phenomenological Considerations of the World of the Obsessive Patient

“…Obsessions and compulsions associated with OCD can be time-consuming (often involving more than 1 h per day) and may significantly interfere with everyday life habits, compromising quality of life [ 7 , 8 ]. In the DSM-5, OCD is recognized within the specific diagnostic category of obsessive-compulsive and related disorders; this deviates from its previous classification within anxiety disorders [ 9 ], reflecting scientific advances [ 10 , 11 , 12 , 13 , 14 ]. However, OCD remains a disorder with paradoxical psychological and behavioral symptoms [ 15 , 16 ] (i.e., ‘certain thoughts can lead to catastrophic events’, ‘thinking of doing something is equivalent to doing it’, and ‘not preventing something is equivalent to causing it’).…”