Causal Pathways to Substance use and Dependence in Young People

吸毒？烟草，酒精和大麻-在英国年轻人中的依赖性很普遍。在16-19岁的年轻人中，四分之一以上的人吸烟;近五分之二的人喝危险饮料;十分之一的人经常吸食大麻。青少年药物使用与教育成绩差和反社会行为有关;在成年早期出现心理问题;并可能导致成年后持续大量饮酒和吸烟，以及随后出现与健康有关的严重问题。青少年使用药物的原因并不单一。潜在的风险包括母亲在怀孕和儿童时期使用药物、家庭贫困以及幼儿期的心理和行为问题。需要更多的证据来梳理这些多重因素的潜在作用，以支持当前和未来的预防战略。这将需要关于早期生活的详细信息，在物质使用之前，以及关于物质使用如何在青春期发展的信息。药物使用的模式也以各种方式界定，迄今没有一个明确的定义。ALSPAC队列，招募1991-2，提供了最好的机会，以帮助我们了解不同的轨迹物质使用在英国的青少年，在什么是最有可能的因果途径导致物质使用和依赖的年轻人，以及物质使用对青少年的不良后果的影响。首先，我们将估计17-18岁时物质使用和依赖的流行率（分别针对烟草，大麻和酒精，以及综合措施）。然后，我们将确定物质使用的不同轨迹。其次，我们将在分析中使用这些物质使用轨迹来测试最有可能的因果途径。也就是说，我们将测试一系列因素是否直接或间接地起作用（通过对其他因素的影响）对青少年物质使用模式的影响，包括母亲在怀孕期间使用物质的影响，儿童时期的多动症和行为障碍，父母使用物质，剥夺，开始使用药物的年龄，以及与大麻代谢相关的基因。第三，我们将研究不同的物质使用轨迹对青少年不良后果的影响（不良教育表现，反社会行为，物质依赖和其他药物使用）。我们将测试物质使用与这些结果有直接或间接因果关系的程度。最后，我们将为未来的遗传研究和有效干预措施的发展提供信息。

Substance use ? tobacco, alcohol and cannabis - and dependence among young people in the UK is widespread. Among young people aged 16-19 over one in four will smoke tobacco; nearly two in five will drink hazardously; one in ten will be regular cannabis smokers. Adolescent substance use is associated with poor educational achievement and antisocial behaviour; psychological problems in early adulthood; and may lead to persistent heavy drinking and smoking in adulthood and the subsequent substantial health related problems. There is no single cause of adolescent substance use. Potential risks include maternal substance use during pregnancy and childhood, family deprivation, and psychological and behavioural problems in early childhood. More evidence is required to tease out the potential contribution of these multiple factors in order to support current and future prevention strategies. This will require detailed information on early life, before substance use, as well as information on how substance use develops during adolescence. Patterns of substance use also have been defined in a variety of ways without a clear definition emerging to date. The ALSPAC cohort, recruited 1991-2, provides the best opportunity to contribute to our understanding of the different trajectories of substance use in adolescents in the UK, on what are the most likely causal pathways leading to substance use and dependence in young people, and on the impact of substance use on adverse adolescent outcomes. Firstly, we will estimate the prevalence of substance use and dependence (separately for tobacco, cannabis and alcohol, and for a combined measure) at age 17-18. We will then identify different trajectories of substance use. Secondly, we will use these substance use trajectories in analyses to test what causal pathways are the most likely. That is, we will test whether a series of factors contribute directly or indirectly (through their impact on other factors) to pattenrs of adolescent substance use, including the influence of maternal substance use whilst pregnant, ADHD and conduct disorder in childhood, parental substance use, deprivation, age starting drug use, and genes associated with cannabis metabolism.Thirdly, we will examine the impact of different substance use trajectories on adverse adolescent outcomes (poor educational performance, antisocial behaviour, substance dependence, and other drug use). We will test the extent to which substance use has a direct or indirect causal link to these outcomes. Finally, we will provide information for future genetic research and for development of effective interventions.