Cortical complexity in eating disorders: a systematic review and qualitative synthesis

Background Eating disorders (EDs) are complex psychiatric conditions with neurodevelopmental and neuroprogressive underpinnings. Altered cortical morphology, including gyrification patterns, may reflect these processes, offering insights into EDs pathophysiology. Objective: This systematic review and qualitative synthesis aimed to describe available neuroimaging findings on cortical complexity, including gyrification and sulcal morphology, in individuals with EDs compared to healthy controls (HC). Methods: Thirteen studies, including 525 patients with anorexia nervosa (AN), 69 patients with bulimia nervosa (BN) and 478 HC, were reviewed. Data on local gyrification index (LGI), sulcal morphology, and related cortical measures were systematically analyzed to identify consistent patterns of brain alterations. Results: A consistent reduction in LGI across frontal, temporal, and parietal regions was reported in patients with acute AN compared to HC. These findings suggest the presence of an altered cortical folding in AN, with alterations that may partially normalize following weight restoration. Studies on bulimia nervosa (BN) are limited, with findings remaining inconclusive. Emerging metrics, such as absolute mean curvature and fractal dimension, provide further insights but lack methodological consistency across studies. Conclusions: Altered cortical folding patterns, particularly decreased gyrification, may reflect neurodevelopmental disruption and the state-dependent effects of malnutrition in AN. Future research should focus on longitudinal studies and standardized neuroimaging methods to clarify these findings and expand knowledge on BN and binge eating disorder (BED).