Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.
Bipolar Disord. 2012 May;14(3):261-70. doi: 10.1111/j.1399-5618.2012.01013.x.
Hippocampal volume decrease associated with illness burden is among the most replicated findings in unipolar depression. The absence of hippocampal volume changes in most studies of individuals with bipolar disorder (BD) may reflect neuroprotective effects of lithium (Li).
We recruited 17 BD patients from specialized Li clinics, with at least two years of regularly monitored Li treatment (Li group), and compared them to 12 BD participants with < 3 months of lifetime Li exposure and no Li treatment within two years prior to the scanning (non-Li group) and 11 healthy controls. All BD patients had at least 10 years of illness and five episodes. We also recruited 13 Li-naïve, young BD participants (15-30 years of age) and 18 sex- and age-matched healthy controls. We compared hippocampal volumes obtained from 1.5-T magnetic resonance imaging (MRI) scans using optimized voxel-based morphometry with small volume correction.
The non-Li group had smaller left hippocampal volumes than controls (corrected p < 0.05), with a trend for lower volumes than the Li group (corrected p < 0.1), which did not differ from controls. Young, Li-naïve BD patients close to the typical age of onset had comparable hippocampal volumes to controls.
Whereas patients with limited lifetime Li exposure had significantly lower hippocampal volumes than controls, patients with comparable illness burden, but with over two years of Li treatment, or young Li-naïve BD patients, showed hippocampal volumes comparable to controls. These results provide indirect support for neuroprotective effects of Li and negative effects of illness burden on hippocampal volumes in bipolar disorders.
与疾病负担相关的海马体积减少是单相抑郁症中最具复制性的发现之一。大多数双相情感障碍（BD）患者的研究中没有海马体积变化，这可能反映了锂（Li）的神经保护作用。
我们从专门的 Li 诊所招募了 17 名 BD 患者，他们至少接受了两年的定期监测 Li 治疗（Li 组），并将他们与 12 名 BD 参与者进行了比较，这些参与者一生中 Li 暴露时间<3 个月，且在扫描前两年内没有 Li 治疗（非 Li 组）和 11 名健康对照者。所有 BD 患者的病程均超过 10 年，发作次数超过 5 次。我们还招募了 13 名 Li 治疗初发、年龄在 15-30 岁之间的年轻 BD 患者和 18 名年龄和性别匹配的健康对照者。我们使用基于体素的形态测量学和小体积校正比较了从 1.5-T 磁共振成像（MRI）扫描获得的海马体体积。
非 Li 组的左侧海马体体积小于对照组（校正后 p<0.05），且体积低于 Li 组的趋势（校正后 p<0.1），但与对照组无差异。接近典型发病年龄的年轻 Li 治疗初发 BD 患者的海马体体积与对照组相当。
尽管一生中 Li 暴露有限的患者的海马体体积明显低于对照组，但具有相似疾病负担、但接受了两年以上 Li 治疗的患者或年轻的 Li 治疗初发 BD 患者的海马体体积与对照组相当。这些结果为 Li 的神经保护作用和疾病负担对双相情感障碍中海马体体积的负面影响提供了间接支持。
