Subcortical shape in pediatric and adult obsessive-compulsive disorder

Abstract

Background: Obsessive-compulsive disorder (OCD) implicates alterations in cortico-striato-thalamo-cortical and fronto-limbic circuits. Building on prior structural findings, this is the largest study to date examining subcortical surface morphometry in OCD.

Methods: Structural magnetic resonance imaging data were collected from 200 participants across development (5-55 years): 28 youth and 75 adults with OCD and 27 psychiatrically healthy youth and 70 adults. General linear models were used to assess group differences and group-by-age interactions on subcortical shape (FSL FIRST).

Results: Compared to healthy participants, those with OCD exhibited surface expansions on the right nucleus accumbens and inward left amygdala deformations, which were associated with greater OCD symptom severity ([Children's] Yale-Brown Obsessive-Compulsive Scale). Group-by-age interactions indicated that accumbens group differences were driven by younger participants and that right pallidum shape was associated inversely with age in healthy participants, but not in participants with OCD. No differences in the shape of other subcortical regions or in volumes (FreeSurfer) were detected in supplementary analyses.

Conclusions: This study is the largest to date examining subcortical shape in OCD and the first to do so across the developmental spectrum. NAcc and amygdala shape deformation builds on extant neuroimaging findings and suggests subtle, subregional alterations beyond volumetric findings. Results shed light on morphometric alterations in OCD, informing current pathophysiological models.

Trial registration: ClinicalTrials.gov NCT02421315 NCT03584945.

Keywords: amygdala; brain; child development; magnetic resonance imaging; neuroimaging; nucleus accumbens; obsessive-compulsive disorder.

Conflict of interest statement

CONFLICT OF INTEREST

The authors declare no conflict of interest.

© 2022 Wiley Periodicals LLC.

Figures

FIGURE 1

Group differences in accumbens and amygdala shape. Comparison of subcortical surface shape between the obsessive-compulsive disorder (OCD) and matched healthy control groups in the full sample (N = 200), covarying for age, sex, and scanner. The figure depicts a significant cluster on the right nucleus accumbens (a) showing more outward deformations for the OCD than the healthy group. The cluster on the left amygdala (b) showed more inward deformations for the OCD than the healthy group. Clusters were identified through threshold-free cluster enhancement (TFCE), corrected to a family-wise error p < .05. Average deformation within these two clusters was extracted and plotted by group (blue open = healthy, red filled = OCD; circle = youth, triangle = adult).

FIGURE 2

Group-by-age interactions on accumbens and pallidum shape. Group-by-age interactions in the full sample (N = 200) covarying for sex and scanner type in the two subcortical structures: (a) right nucleus accumbens (negative interaction, blue), (B) right pallidum (positive interaction, red). Clusters were identified through threshold-free cluster enhancement (TFCE), corrected to a family-wise error p < .05. Average deformation within these two clusters was extracted; associations between age and average deformation were plotted plot by group (blue open = healthy, red filled = OCD; circle = youth, triangle = adult). Gray vertical lines indicate the bounds of Johnson–Neyman post hoc analyses; group differences were significant at younger and early ages outside of these lines. Significant age effects within group are noted: *p < .05, **p < .01, ***p < .001.