Effects of cognitive behavioral therapy on white matter integrity in first-episode adult major depressive disorder

Abstract

Objective To investigate the effect of cognitive behavioral therapy (CBT) on the white matter microstructural changes in first-episode untreated major depressive disorder (MDD) adult patients. Methods Fourteen first-episode, medication-naive MDD patients and 15 healthy subjects as controls underwent diffusion tensor imaging (DTI) scan and assessment at baseline. Then, the patients received 28-week CBT treatment, and were given the second scan when finished. Fractional anisotropy (FA) was compared to indirectly explore abnormality of white matter in depressed patients and healthy subjects, and before-after treatments, using whole brain tract-based spatial statistic (TBSS) analysis. The clinical symptoms were assessed by psychiatrists using HAMD24. The relationship between the FA values of regions changed before and after CBT and the duration, scores of HAMD24 were analyzed by using Pearson correlation analysis. Results Post-treatment, MDD patients showed a significant reduction in HAMD24 (t=23.773,P<0.01). Compared with controls, the MDD patients showed a trend for lower value of FA in the right frontal lobe (MNI: x=20, y=14, z=58, P=0.001), the left temporal lobe (MNI: x=-50, y=-7, z=-24, P=0.006), the right hippocampus (MNI: x=21, y=-32, z=-5, P=0.004) and the left angular region (MNI: x=-45, y=-56, z=34, P=0.007) before CBT. After CBT, MDD patients still showed lower value of FA in the right frontal lobe (MNI: x=18, y=14, z=55, P=0.001), the right hippocampus (MNI: x=21, y=-33, z=-5, P=0.003) and the left angular region (MNI: x=-44, y=-57, z=34, P=0.006), and only the FA value of left temporal lobe came back to normal after 28 weeks treatment. MDD patients also showed increased FA value in the left cerebellum (MNI: x=-16, y=-55, z=-44, P=0.025) from pro-to post-treatment. Duration were not correlated with left temporal lobe (r=-0.188, P=0.520) and left cerebellum (r=-0.090, P=0.760) in patients. Scores of HAMD24 were also not correlated with left temporal lobe (before CBT: r=-0.105, P=0.722; after CBT: r=-0.152, P=0.603) and left cerebellum (before CBT: r=-0.224, P=0.441; after CBT: r=-0.167, P=0.568) in patients. Conclusion CBT may induce white matter changes in temporal lobe and cerebellum in MDD patients, and may play a role in improving depressive symptom. Key words: Depressive disorder; Cognitive therapy; Diffusion tensor imaging; Temporal lobe; Tract-based spatial statistic