Department of Psychiatry Mental Health, University of Cape Town, South Africa.
Anxiety and Stress Disorders Research Unit, Medical Research Council, South Africa.
Addict Biol. 2018 Jan;23(1):347-358. doi: 10.1111/adb.12478. Epub 2016 Dec 5.
Chronic methamphetamine use is associated with executive functioning deficits that suggest dysfunctional cognitive control networks (CCNs) in the brain. Likewise, abnormal connectivity between intrinsic CCNs and default mode networks (DMNs) has also been associated with poor cognitive function in clinical populations. Accordingly, we tested the extent to which methamphetamine use predicts abnormal connectivity between these networks, and whether, as predicted, these abnormalities are compounded in patients with a history of methamphetamine-associated psychosis (MAP). Resting-state fMRI data were acquired from 46 methamphetamine-dependent patients [19 with MAP, 27 without (MD)], as well as 26 healthy controls (CTRL). Multivariate network modelling and whole-brain voxel-wise connectivity analyses were conducted to identify group differences in intrinsic connectivity across four cognitive control and three DMN networks identified using an independent components analysis approach (meta-ICA). The relationship of network connectivity and psychotic symptom severity, as well as antipsychotic treatment and methamphetamine use variables, was also investigated. Robust evidence of hyper-connectivity was observed between the right frontoparietal and anterior DMN networks in MAP patients, and 'normalized' with increased duration of treatment with antipsychotics. Attenuation of anticorrelated anterior DMN-dorsal attention network activity was also restricted to this group. Elevated coupling detected in MD participants between anterior and posterior DMN networks became less apparent with increasing duration of abstinence from methamphetamine. In summary, we observed both alterations of RSN connectivity between DMN networks with chronic methamphetamine exposure, as well as DMN-CCN coupling abnormalities consistent with possible MAP-specific frontoparietal deficits in the biasing of task-appropriate network activity.
慢性甲基苯丙胺使用与执行功能缺陷有关，这表明大脑中的认知控制网络（CCNs）功能失调。同样，内在 CCN 与默认模式网络（DMN）之间的异常连接也与临床人群中认知功能差有关。因此，我们测试了甲基苯丙胺使用程度对这些网络之间异常连接的预测作用，以及这些异常是否如预期的那样在有甲基苯丙胺相关精神病（MAP）病史的患者中更为复杂。从 46 名甲基苯丙胺依赖患者（19 名有 MAP，27 名无（MD））以及 26 名健康对照（CTRL）中获取静息状态 fMRI 数据。使用独立成分分析方法（元 ICA）对四个认知控制和三个 DMN 网络进行了多变量网络建模和全脑体素连接分析，以识别组间内在连接的差异。还研究了网络连接与精神病症状严重程度以及抗精神病药物治疗和甲基苯丙胺使用变量的关系。在 MAP 患者中，观察到右额顶和前 DMN 网络之间存在明显的超连接现象，并且随着抗精神病药物治疗时间的增加而“正常化”。前 DMN-背侧注意力网络活动的去相关衰减也仅限于该组。与慢性甲基苯丙胺暴露相关，除了 DMN-CCN 耦合异常外，我们还观察到 MD 参与者之间的前 DMN 和后 DMN 网络之间的耦合增加，随着甲基苯丙胺禁欲时间的增加，这种耦合变得不那么明显。总之，我们观察到慢性甲基苯丙胺暴露导致 DMN 网络之间 RSN 连接的改变，以及 DMN-CCN 耦合异常，这与可能的 MAP 特定额顶叶缺陷一致，即适当任务的网络活动偏向。
