Hidese S, et al. – The present study was carried out to investigate the possible association of obesity with cognitive function and brain structure in patients with major depressive disorder (MDD). The results of this study showed that obesity was related to reduced cognitive function, decreased gray matter volume, and impaired white matter integrity in cognition–related brain areas in patients with MDD.

Methods

• 307 patients with MDD and 294 healthy members, matched for age, sex, ethnicity (Japanese), and handedness (right) were enrolled for the examination.
• Using the Brief Assessment of Cognition in Schizophrenia (BACS), cognitive function was assessed.
• Gray and white matter structures were investigated utilizing voxel-based morphometry and diffusion tensor imaging in a subsample of patients (n=114) whose magnetic resonance imaging (MRI) data were obtained utilizing a 1.5 T MRI system.

Results

• The study results showed that verbal memory, working memory, motor speed, attention, executive function, and BACS composite scores were lower for the MDD patients than for the healthy participants (p<0.05).
• Findings revealed that among the patient group, working memory, motor speed, executive function, and BACS composite scores were lower in obese patients (body mass index ≥ 30, n=17) as compared to non-obese patients (n=290, p<0.05, corrected).
• It was noted that MRI determined frontal, temporal, thalamic, and hippocampal volumes, and white matter fractional anisotropy values in the internal capsule and left optic radiation were decreased in obese patients (n=7) than in non-obese patients (n=107, p<0.05, corrected).