Institute of Psychological Medicine and Clinical Neurosciences, School of Psychology, Cardiff University, Heath Park, Cardiff, United Kingdom.
Biol Psychiatry. 2012 Aug 15;72(4):296-302. doi: 10.1016/j.biopsych.2012.01.022. Epub 2012 Mar 2.
Altered white matter microstructure in tracts integral to mood regulation networks could underlie vulnerability to major depressive disorder (MDD). Guided by functional magnetic resonance studies, we explored whether a positive family history of MDD (FH+) and anhedonia (reduced capacity for pleasure) were associated with altered white matter microstructure in the cingulum bundles and uncinate fasciculi.
Diffusion tensor magnetic resonance imaging data were acquired on 34 healthy female student volunteers (mean age 22 years). Exclusion criteria included other current or previous psychiatric disorder, current depression, and current psychotropic medication. Family history was determined using established criteria. Fiber tractography was performed for each individual for a priori tracts of interest and a comparison tract. Mean fractional anisotropy (FA), an index of microstructure, was calculated for each tract.
Tracts were reconstructed in 18 FH+ individuals and 15 FH- individuals, who did not differ by age or subclinical depressive symptoms. FH+ subjects had 3% to 5% lower FA in the right and left cingulum bundles than FH- individuals (p = .012, p = .059, respectively). Post hoc analysis demonstrated 8% lower FA in the left subgenual cingulate (p = .007). Hedonic tone correlated positively with FA in the right and left cingulum bundles (r = .342, p = .052; r = .477, p = .005, respectively), and the left subgenual cingulum (r = .500, p = .003).
Both family history of MDD and subclinical anhedonia are associated with reduced FA in the bilateral cingulum bundles, particularly in the left subgenual cingulum. Altered cingulum white matter architecture is implicated in the etiology of MDD.
调节情绪的网络中与功能相关的白质微结构的改变可能是导致重度抑郁症（MDD）易感性的原因。本研究在功能磁共振研究的指导下，探讨了 MDD 阳性家族史（FH+）和快感缺失（愉悦感降低）是否与扣带束和钩束的白质微结构改变有关。
对 34 名健康的女学生志愿者（平均年龄 22 岁）进行了弥散张量磁共振成像数据采集。排除标准包括其他当前或以前的精神障碍、当前的抑郁和当前的精神药物治疗。家族史采用既定标准确定。对每个个体进行纤维束追踪，以获得先验感兴趣的束和比较束。为每个束计算平均各向异性分数（FA），作为微结构的指标。
在 18 名 FH+个体和 15 名 FH-个体中重建了束，FH+和 FH-个体在年龄或亚临床抑郁症状上没有差异。FH+受试者的右侧和左侧扣带束的 FA 比 FH-个体低 3%至 5%（p =.012，p =.059）。事后分析表明，左前扣带皮质的 FA 降低 8%（p =.007）。快感与右侧和左侧扣带束的 FA 呈正相关（r =.342，p =.052；r =.477，p =.005），与左侧前扣带皮质的 FA 呈正相关（r =.500，p =.003）。
MDD 的家族史和亚临床快感缺失均与双侧扣带束，尤其是左侧前扣带皮质的 FA 降低有关。扣带束白质结构的改变与 MDD 的发病机制有关。
