Structural brain abnormalities in multiple sclerosis patients with major depression

To assess the association between major depression and structural brain abnormalities in patients with multiple sclerosis (MS).

Two groups of patients with clinically definite MS were studied: 21 with Diagnostic and Statistical Manual of Mental Disorders (4th ed.)-defined major depression and 19 without. The groups did not differ on demographic, disease, or cognitive measures. All subjects underwent brain MRI. Tissue segmentation and regional brain masking were applied to the MRI data.

Compared with the euthymic subjects, those with major depression had a greater T2-weighted lesion volume (p = 0.003) and more extensive T1-weighted lesion volume in the left medial inferior prefrontal cortex (p = 0.01) and less gray matter volume (p = 0.01) and more CSF volume in the left anterior temporal region (p = 0.005). A logistic regression analysis identified two independent predictors of depression: left medial inferior prefrontal cortex T2 lesion volume and left anterior temporal CSF volume. These variables accounted for 42% of the depression variance score.

Whereas both lesion burden and atrophy are important in the pathogenesis of depression in MS, psychosocial influences should also be considered.