Morphometry variations of orbitofrontal regions for increased BMI and appetite in major depression

However, it is unclear if conceptually related atypical symptoms of changes in appetite are associated with similar neural alterations and if BMI and increasedappetite are also associated with white matter alterations. We employed a multi model structural neuroimaging approach to investigate the relationship between orbitofrontal gray and white matter with recent changes in appetite and BMI in a sample of N = 715 major depressive disorder patients. We found that increased BMI was associated with significantly lower cortical thickness and lower gray matter density in the right OFC, and in particular its medial aspect. For change in appetite, in contrast, we did not find any significant association with OFC morphometry, nor with OFC white matter connections. Bayesian model comparisons further suggested that BMI alone, but not change in appetite or a combination of both explained variance in cortical thickness of the right OFC. We further found strong to decisive evidence for the absence of an effect of BMI and appetite for most other analyses, including surface area and DTI measures of all OFC regions. Taken together, our findings thus suggest that BMI related alterations in OFC morphometry cannot be traced back to changes in appetite in major depression, indicating a region and modality specific effect for BMI.