Correlation between depressive and anxious symptoms and white matter changes in relatives of people with epilepsy

Background: depression and anxiety are common symptoms observed in people with epilepsy and their relatives. Objective: Investigate associations between white matter (WM) changes and psychiatric symptoms in relatives of TLE patients. Methods: We analyzed brain MRI with DTI from 40 TLE relatives and applied the Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI). We extracted 6 WM tracts (fornix, cingulum, uncinate fasciculus (UF), inferior fronto-occipital fasciculus, corpus callosum, corticospinal tract) and analyzed fractional anisotropy (FA), medium diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD). We investigated correlations between scores and the DTI measures. Symptoms of depression were positive with BDI scores above 10, while symptoms of anxiety were positive with BAI scores above 11. Results: we observed a prevalence of 37.5% of depressive symptoms and 27.5% of anxious symptoms. BDI correlated with FA in the left cingulum (p=0.0003;r=-0.547); and with MD in the right cingulum (p=0.015;r=0.401) and right and left UF (p=0.023;r=0.374 and p=0.021;r=0.363). BDI correlated also with RD in the left and right cingulum (p=0.0003;r=0.583 and p=0.015;r=0.401). BAI correlated with fornix`s FA (p=0.026;r=- 0.352), and with MD in the left cingulum (p=0.01;r=0.415) and left UF (p=0.003;r=0.374) and with RD in the left cingulum (p=0.022;r=0.371) and left UF (p=0.01;r=0.440). Discussion: The regions correlated with psychiatric symptoms here overlap with those affected in patients with epilepsy, however, they differ from areas mainly affected in patients with isolated depression. We hypothesize a possible genetic substrate involved in comorbidity between epilepsy and depression, distinct from psychiatric disease in people without epilepsy.