The Norwegian Centre for Mental Disorders Research (NORMENT), Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
Department of Psychiatry, Telemark Hospital, Skien, Norway.
Psychol Med. 2024 Jul;54(10):2369-2379. doi: 10.1017/S0033291724000503. Epub 2024 Apr 2.
Dysmyelination could be part of the pathophysiology of schizophrenia spectrum (SCZ) and bipolar disorders (BPD), yet few studies have examined myelination of the cerebral cortex. The ratio of T1- and T2-weighted magnetic resonance images (MRI) correlates with intracortical myelin. We investigated the T1w/T2w-ratio and its age trajectories in patients and healthy controls (CTR) and explored associations with antipsychotic medication use and psychotic symptoms.
Patients with SCZ ( = 64; mean age = 30.4 years, s.d. = 9.8), BPD ( = 91; mean age 31.0 years, s.d. = 10.2), and CTR ( = 155; mean age = 31.9 years, s.d. = 9.1) who participated in the TOP study (NORMENT, University of Oslo, Norway) were clinically assessed and scanned using a General Electric 3 T MRI system. T1w/T2w-ratio images were computed using an optimized pipeline with intensity normalization and field inhomogeneity correction. Vertex-wise regression models were used to compare groups and examine group × age interactions. In regions showing significant differences, we explored associations with antipsychotic medication use and psychotic symptoms.
No main effect of diagnosis was found. However, age slopes of the T1w/T2w-ratio differed significantly between SCZ and CTR, predominantly in frontal and temporal lobe regions: Lower T1w/T2w-ratio values with higher age were found in CTR, but not in SCZ. Follow-up analyses revealed a more positive age slope in patients who were using antipsychotics and patients using higher chlorpromazine-equivalent doses.
While we found no evidence of reduced intracortical myelin in SCZ or BPD relative to CTR, different regional age trajectories in SCZ may suggest a promyelinating effect of antipsychotic medication.
脱髓鞘可能是精神分裂症谱系 (SCZ) 和双相情感障碍 (BPD) 病理生理学的一部分，但很少有研究检查大脑皮层的髓鞘形成。T1 和 T2 加权磁共振成像 (MRI) 的比值与皮质内髓鞘相关。我们研究了患者和健康对照组 (CTR) 的 T1w/T2w 比值及其年龄轨迹，并探讨了与抗精神病药物使用和精神病症状的关联。
参加 TOP 研究（NORMENT，奥斯陆大学，挪威）的 SCZ 患者 ( = 64；平均年龄 = 30.4 岁，标准差 = 9.8)、BPD 患者 ( = 91；平均年龄 31.0 岁，标准差 = 10.2) 和 CTR ( = 155；平均年龄 = 31.9 岁，标准差 = 9.1) 进行了临床评估和使用通用电气 3T MRI 系统进行扫描。T1w/T2w 比值图像使用优化的管道进行计算，包括强度归一化和场不均匀性校正。顶点回归模型用于比较组并检查组 × 年龄的相互作用。在显示显著差异的区域，我们探讨了与抗精神病药物使用和精神病症状的关联。
未发现诊断的主要作用。然而，SCZ 和 CTR 之间 T1w/T2w 比值的年龄斜率存在显著差异，主要在前额和颞叶区域：在 CTR 中，随着年龄的增长，T1w/T2w 比值值降低，但在 SCZ 中没有。随访分析显示，使用抗精神病药物和使用更高氯丙嗪等效剂量的患者的年龄斜率更为积极。
虽然我们没有发现 SCZ 或 BPD 相对于 CTR 的皮质内髓鞘减少的证据，但 SCZ 中不同的区域年龄轨迹可能表明抗精神病药物具有促髓鞘形成作用。
