A PROSPECTIVE STUDY OF STRUCTURAL CONNECTIVITY IN ADOLESCENTS WITH MAJOR DEPRESSIVE DISORDER: A PRELIMINARY STUDY

초록

Objectives Diffusion tensor imaging (DTI) studies have detected microstructural changes of white matter in depressive disorder. However, white matter alterations in adolescents with MDD remain to be explored further as DTI studies report contrasting results. To explore this subject, we report findings from longitudinal voxelwise analyses of DTI data collected at baseline and at 12-week follow-up on 12 adolescents. Methods We recruited drug-naïve adolescents with MDD. They were at initial onset. The patients were evaluated initially and followed-up prospectively for 12 weeks after starting antidepressant medication and evaluated again at 12 weeks. We conducted a whole-brain, tract-based spatial statistical (TBSS) analysis of DTI-derived parameters, including fractional anisotropy (FA) and mean diffusivity (MD). Results A total of 12 adolescents between ages 13 and 18 with MDD participated in the study. FMRIB Software Library’s TBSS established voxel-level differences in the comparison between pretreatment and posttreatment parameter–fractional anisotropy. Whole-brain TBSS ( P < 0.05) showed FA value differences in the caudate, insula, putamen, and thalamus in the comparison between pretreatment and posttreatment. Those regions are known to be central in emotional and cognitive processing. The structural connectivity in these regions was shown to change according to the 12-week antidepressant treatment. However, correlational analyses did not reveal any significant association of FA and Hamilton depression rating scale score. Conclusions These findings confirm the presence of microstructural white matter alterations in adolescents with MDD according to the disease condition. DTI could be a useful tool in detecting longitudinal changes after pharmacological treatment with antidepressants in adolescents with MDD. Further studies involving larger case numbers are needed to detect the long-term effect of antidepressant treatment on the brains of adolescents with mood disorders.