Department of Psychiatry and Behavioral Science, Stony Brook University Stony Brook, NY, USA ; Department of Psychiatry, Columbia University New York, NY, USA.
Front Psychiatry. 2013 Mar 6;4:5. doi: 10.3389/fpsyt.2013.00005. eCollection 2013.
Pre-treatment differences in serotonergic binding between those who remit to antidepressant treatment and those who do not have been found using Positron Emission Tomography (PET). To investigate these differences, an exploratory study was performed using a second imaging modality, diffusion-weighted MRI (DW-MRI). Eighteen antidepressant-free subjects with Major Depressive Disorder received a 25-direction DW-MRI scan prior to 8 weeks of selective serotonin reuptake inhibitor treatment. Probabilistic tractography was performed between the midbrain/raphe and two target regions implicated in depression pathophysiology (amygdala and hippocampus). Average fractional anisotropy (FA) within the derived tracts was compared between SSRI remitters and non-remitters, and correlation between pre-treatment FA values and SSRI treatment outcome was assessed. Results indicate that average FA in DW-MRI-derived tracts to the right amygdala was significantly lower in non-remitters (0.55 ± 0.04) than remitters (0.61 ± 0.04, p < 0.01). In addition, there was a significant correlation between average FA in tracts to the right amygdala and SSRI treatment response. These relationships were found at a trend level when using the left amygdala as a tractography target. No significant differences were observed when using the hippocampus as target. These regional differences, consistent with previous PET findings, suggest that the integrity and/or number of white matter fibers terminating in the right amygdala may be compromised in SSRI non-remitters. Further, this study points to the benefits of multimodal imaging and suggests that DW-MRI may provide a pre-treatment signature of SSRI depression remission at 8 weeks.
在使用正电子发射断层扫描（PET）的研究中发现，接受抗抑郁治疗后缓解和未缓解的患者之间，其治疗前的 5-羟色胺能结合存在差异。为了研究这些差异，本研究采用第二种成像方式——弥散加权磁共振成像（DW-MRI）进行了探索性研究。18 名无抗抑郁药物的重度抑郁症患者在接受选择性 5-羟色胺再摄取抑制剂治疗 8 周前接受了 25 个方向的 DW-MRI 扫描。对中脑/中缝核和两个与抑郁病理生理学相关的目标区域（杏仁核和海马体）之间的弥散张量纤维束进行概率追踪。在衍生的束内比较 SSRI 缓解者和非缓解者之间的平均各向异性分数（FA），并评估治疗前 FA 值与 SSRI 治疗结果之间的相关性。结果表明，右侧杏仁核 DW-MRI 衍生束的平均 FA 在非缓解者（0.55±0.04）中显著低于缓解者（0.61±0.04，p<0.01）。此外，右侧杏仁核束的平均 FA 与 SSRI 治疗反应之间存在显著相关性。当以左侧杏仁核作为追踪目标时，这些关系具有趋势水平。当使用海马体作为目标时，未观察到显著差异。这些与之前的 PET 研究结果一致的区域差异表明，在 SSRI 非缓解者中，终止于右侧杏仁核的白质纤维的完整性和/或数量可能受损。此外，本研究指出了多模态成像的优势，并表明 DW-MRI 可能在 8 周时提供 SSRI 抑郁缓解的治疗前特征。
