Background

Impairments in inhibitory control and its underlying brain networks (control/salience areas) are associated with substance misuse. Research often assumes a causal substance exposure effect on brain structure. This assumption remains largely untested, and other factors (e.g., familial risk) may confound exposure effects. We leveraged a genetically informative sample of twins aged 24 years and a quasi-experimental co-twin control design to separate alcohol or cannabis exposure effects during emerging adulthood from familial risk on control/salience network cortical thickness.

Methods

In a population-based sample of 436 twins aged 24 years, dimensional measures of alcohol and cannabis use (e.g., frequency, density, quantity, intoxications) across emerging adulthood were assessed. Cortical thickness of control/salience network areas were assessed using magnetic resonance imaging and defined by a fine-grained cortical atlas.

Results

Greater alcohol, but not cannabis, misuse was associated with reduced thickness of prefrontal (e.g., dorso/ventrolateral, right frontal operculum) and frontal medial cortices, as well as temporal lobe, intraparietal sulcus, insula, parietal operculum, precuneus, and parietal medial areas. Effects were predominately (pre)frontal and right lateralized. Co-twin control analyses suggested that the effects likely reflect both the familial predisposition to misuse alcohol and, specifically for lateral prefrontal, frontal/parietal medial, and right frontal operculum, an alcohol exposure effect.

Conclusions

This study provides novel evidence that alcohol-related reductions in cortical thickness of control/salience brain networks likely represent the effects of alcohol exposure and premorbid characteristics of the genetic predisposition to misuse alcohol. The dual effects of these two alcohol-related causal influences have important and complementary implications regarding public health and prevention efforts to curb youth drinking.

中文翻译：

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酒精和大麻使用对新兴成年期认知控制和显着性脑网络的皮质厚度的影响：一项双胞胎对照研究

背景

抑制性控制及其潜在的大脑网络（控制/显着区域）的损害与物质滥用有关。研究通常假设因果物质暴露对大脑结构有影响。这一假设在很大程度上仍未得到检验，其他因素（例如，家庭风险）可能会混淆暴露效应。我们利用 24 岁双胞胎的遗传信息样本和准实验性双胞胎控制设计，将成年期的酒精或大麻暴露效应与控制/显着网络皮质厚度的家族风险区分开来。

方法

在一个包含 436 名 24 岁双胞胎的人群样本中，评估了成年后酒精和大麻使用的维度测量（例如，频率、密度、数量、中毒）。使用磁共振成像评估控制/显着网络区域的皮质厚度，并由细粒度的皮质图谱定义。

结果

更多的酒精滥用（而非大麻）与前额叶（例如，背侧/腹外侧、右侧额叶岛盖）和额内侧皮质以及颞叶、顶内沟、岛叶、顶叶岛盖、楔前叶和顶叶内侧的厚度减少有关领域。影响主要是（前）额叶和右侧。双胞胎对照分析表明，这些影响可能反映了家族滥用酒精的倾向，特别是对于外侧前额叶、额叶/顶叶内侧和右额叶盖，酒精暴露效应。

结论

这项研究提供了新的证据，表明与酒精相关的控制/显着大脑网络皮质厚度的减少可能代表了酒精暴露的影响和滥用酒精的遗传倾向的病前特征。这两种与酒精有关的因果影响的双重影响对公共卫生和遏制青少年饮酒的预防工作具有重要且互补的意义。