Individuals with cognitive problems may be predisposed to develop substance use disorders; therefore, differences in cognitive function between methamphetamine users and control participants may be attributable to premorbid factors rather than methamphetamine use. The goal of this study was to clarify the extent to which this is the case. Childhood academic transcripts were obtained for 37 methamphetamine-dependent adults and 41 control participants of similar educational level and premorbid IQ. Each participant completed a comprehensive cognitive battery and received a structural magnetic resonance imaging scan. Data from control participants and linear regression were used to develop a normative model to describe the relationship between childhood academic performance and scores on the cognitive battery. Using this model, cognitive performance of methamphetamine users was predicted from their premorbid academic scores. Results indicated that methamphetamine users' childhood grade point average was significantly lower than that of the control group (p < 0.05). Further, methamphetamine users' overall cognitive performance was lower than was predicted from their grade point average prior to methamphetamine use (p = 0.001), with specific deficits in attention/concentration and memory (ps < 0.01). Memory deficits were associated with lower whole-brain cortical thickness (p < 0.05). Thus, in addition to having an apparent premorbid weakness in cognition, methamphetamine users exhibit subsequent cognitive function that is significantly lower than premorbid estimates would predict. The results support the view that chronic methamphetamine use causes a decline in cognition and/or a failure to develop normative cognitive abilities, although aside from methamphetamine use per se, other drug use and unidentified factors likely contribute to the observed effects.

中文翻译：

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甲基苯丙胺使用者相对于儿童学业成绩的认知缺陷：与皮层厚度有关。

有认知问题的人可能容易患上药物滥用症；因此，甲基苯丙胺使用者和对照组参与者在认知功能上的差异可能归因于发病前因素，而不是甲基苯丙胺的使用。这项研究的目的是澄清这种情况的程度。从37名依赖甲基苯丙胺的成年人和41名具有相似教育水平和病前智商的对照组参与者那里获得了儿童成绩单。每个参与者都完成了一次全面的认知训练，并接受了结构磁共振成像扫描。来自对照参与者和线性回归的数据用于建立规范模型，以描述儿童学业成绩与认知能力得分之间的关​​系。使用这个模型，根据甲基苯丙胺使用者的病前学业成绩预测他们的认知表现。结果表明，甲基苯丙胺使用者的儿童平均成绩明显低于对照组（p <0.05）。此外，甲基苯丙胺使用者的总体认知表现低于使用甲基苯丙胺之前的平均成绩预测值（p = 0.001），注意力/集中力和记忆力有特定缺陷（ps <0.01）。记忆障碍与较低的全脑皮层厚度有关（p <0.05）。因此，除了具有明显的病前认知弱点之外，甲基苯丙胺使用者还表现出随后的认知功能，该认知功能明显低于病前估计的预期。