THE EFFECT OF PHARMACOTHERAPY ON STRUCTURAL CONNECTIVITY IN FIRST-EPISODE DRUG-NAIVE ADOLESCENTS WITH MDD: A THREE-MONTH PROSPECTIVE FOLLOW-UP STUDY

초록

Objectives MDD is a quite common mental disorder in adolescents and understanding the neurobiological mechanism of MDD has developed these days. In this study, we aimed to compare the difference in connectivity between MDD patients and healthy control (HC) subjects by using diffuse tensor imaging (DTI). We also investigated the change of structural connectivity in the patients between pretreatment and 3-month follow-up posttreatment. We wanted to find out the influence of mental health treatment on the structural connectivity of adolescent patients with MDD. Methods A total of 53 participants (26 patients and 27 HC subjects) were recruited in the study. We recruited patients aged 13–18 years who were diagnosed with MDD using DSM-IV -Text Revision by the child and adolescent psychiatrist. The symptoms of MDD were measured using the Hamilton depression rating scale (HAMD) and Korean form of the Kovac’s children’s depression inventory. FMRIB Software Library 5.0 and tract-based spatial statistics were used for statistical analysis. DTI metrics [fractional anisotropy (FA), radial diffusivity (RD), mean diffusivity (MD), and axial diffusivity (AD)] were measured using DTI. Results IQ, duration of untreated period, and HAMD scores were included as a covariate. When comparing pretreatment MDD and HC, the difference was not statistically significant, but there was a tendency of lower FA in right superior longitudinal fasciculus and right inferior fronto-occipital fasciculus in the patients ( p = 0.07 and 0.08, respectively). Nineteen patients (8 males and 11 females) were followed up after 3 months of pharmacological treatment. According to the severity of HAMD, 6 patients were symptom-free, 9 were mildly depressed, and 4 were moderately depressed at the 3-month follow-up evaluation. Comparison between pretreatment and 3-month follow-up posttreatment did not have any statistically significant difference. Conclusions Our results indicated that even a single depressive episode could affect structural connectivity. We assumed that recovery of MDD could restore the connectivity, but it was not statistically significant in the 3-month follow-up. The relatively short duration of treatment and the residual depressive symptoms after the partial resolution might have effects on the results.