Adult consequences of youth substance use: Twin study enriched for SUD risk

描述（由申请人提供）：青春期和成年期是一个重要的发育时期，在此期间，物质使用、误用和滥用伴随着神经认知发育、心理健康和社会环境的重要变化，并对成人适应产生影响。现有的文献链接青少年物质使用的影响，成人的调整表明这些因素的重要性，但在很大程度上是相互关联和横截面，并留下模棱两可的因果关系的作用。不良的成人适应可能是青少年滥用药物的结果，包括在这个敏感时期对大脑发育可能产生的神经毒性影响。然而，在物质使用开始之前存在的因素，如遗传易感性、反映遗传风险表现的预先存在的大脑异常、背景风险和共病障碍如儿童期破坏性障碍（CDDs），影响青少年物质暴露和成人结局。现有的研究通常没有考虑到这些因素。因此，即使是为数不多的纵向研究，也只限于它们所允许的推论。我们建议对453对双胞胎进行一项前瞻性研究，首先在11岁时进行评估，以确定24岁时的年轻成年人结局。为了增加滥用药物的可能性，并确保高风险女性的充分代表性，我们的社区为基础的双胞胎样本的一半是丰富的CDDs的存在;另一半是随机选择的，因此是在明尼苏达州出生的双胞胎的代表。研究参与者完成了为期一天的亲自摄入评估，包括物质使用，心理健康，整体调整，环境风险和保护因素，电生理测量，学业成绩和认知能力。参与者在14岁时重新评估，当时许多人开始使用药物，并在17岁时再次评估，当时药物滥用变得明显。我们的样本的当前值来自于已经收集的关于暴露于特定物质的时间、持续时间、频率和强度的大量数据，以及我们对双胞胎在整个青春期的行为、环境和家庭特征的仔细评估。我们将利用这一样本的价值，对24岁的结果进行全面评估，广泛涵盖物质使用障碍、心理健康（包括持续性CDDs）以及心理社会、电生理和神经心理学结果。216对双胞胎的子样本也将接受MRI评估，增加了我们研究的独特性。我们的数据分析策略强调了双胞胎差异设计的创新应用，这是一种强大的方法，用于澄清由于物质使用而产生的影响，以及由于不可测量的混杂因素（包括遗传因素）而产生的影响。这种新颖的方法利用了双胞胎在成长过程中自然发生的物质滥用史的差异，使我们能够将物质滥用的影响与物质暴露前的家庭和心理社会风险因素分开，这些因素对他们的整体调整和成年后的大脑功能有影响。1

DESCRIPTION (provided by applicant): Adolescence and emerging adulthood represent an important developmental period during which substance use, misuse, and abuse occur concomitantly with important changes in neurocognitive development, mental health, and the social environment, with consequences for adult adjustment. Existing literature linking the effects of youth substance use to adult adjustment demonstrates the importance of these factors, but is largely correlational and cross-sectional, and leaves equivocal their causal role. Poor adult adjustment may be the result of youth substance misuse, including possible neurotoxic effects on brain development during this sensitive period. However, factors present prior to substance use initiation, such as genetic liability, pre- existing brain anomalies reflectng the manifestation of genetic risk, contextual risk, and comorbid disorders such as childhood disruptive disorders (CDDs), influence both adolescent substance exposure and adult outcomes. Existing research has typically not accounted for such factors. Thus, even the few longitudinal studies that exist are limited in the inferences they permit. We propose extending a prospective study of 453 twin pairs, first assessed at age 11, to determine young adult outcomes at age 24. To increase the likelihood that misuse of substances would be widespread and to ensure sufficient representation of high-risk females, half of our community-based twin sample was enriched for the presence of CDDs; the other half was selected at random and is thus representative of twins born in Minnesota. Study participants completed a day-long in- person intake assessment that included substance use, mental health, overall adjustment, environmental risk and protective factors, electrophysiological measurement, academic achievement, and cognitive ability. Participants were re-assessed at age 14, when many were initiating substance use, and again at age 17, when substance misuse was becoming apparent. Our sample's current value derives from the wealth of data already gathered on the timing, duration, frequency, and intensity of exposure to specific substances coupled with our careful assessments of the twins' behavioral, environmental, and familial characteristics throughout adolescence. We will capitalize on the value of this sample by undertaking a comprehensive assessment of age-24 outcomes that broadly covers substance use disorders, mental health (including persistence of CDDs), and psychosocial, electrophysiological, and neuropsychological outcomes. A subsample of 216 twin pairs will also undergo an MRI assessment, adding to the uniqueness of our study. Our data analytic strategy emphasizes the innovative application of a co-twin differences design, a powerful method for clarifying effects due to substance use from those due to unmeasured confounding factors, including genetic factors. This novel approach capitalizes on the differences in the history of substance misuse that occur naturally within twin pairs as they grow up, allowing us to separate the effects of substance abuse from familial and psychosocial risk factors that predate substance exposure on their overall adjustment and brain functioning as adults. 1