Decision-Making and Episodic Memory in Trajectories to Cannabis Addiction

描述(申请人提供)：在美国，对大麻上瘾的人比对任何其他非法药物都要多，而且大麻的使用率正在上升，同时青少年对大麻的不赞成和对其危害的认识也在下降。青春期前额叶皮质的重要成熟变化可能使年轻人比成年人更容易受到大麻不良影响的影响。事实上，研究表明，大量吸食大麻的人在记忆表现和决策能力方面存在障碍，他们中的大多数人在青春期就开始吸食大麻。然而，从最初的实验到大麻成瘾的发展，决策和记忆是如何受到影响的，人们知之甚少。此外，在科学文献中存在争议的是，在大量吸食大麻的人中观察到的决策障碍是由于大麻对大脑功能的有害影响，还是可能是发展成大麻成瘾的先行风险因素。这项提案的主要目标是确定：a)决策是否是大麻成瘾的先行风险因素；以及b)不同的大麻使用轨迹在决策和情景记忆方面发生了什么变化。参与者将是400名年龄在14岁至16岁之间的年轻人，他们中的大多数人都曾尝试过大麻，但尚未上瘾。在两年多的时间里，每12个月对他们的决策和情景记忆进行一次评估，每6个月对他们的药物使用和大麻成瘾症状进行一次评估。假设基线决策较差与在后续行动中发展成大麻成瘾的风险增加有关。随着时间的推移，大麻消费量不断上升的人，其情景记忆的恶化程度将比在其他(非升级或停止)大麻使用轨迹中观察到的更严重。相比之下，决策在所有轨迹上几乎没有变化，这与其作为大麻成瘾的前兆而不是结果的假设角色是一致的。在后续行动中观察到的决策的任何下降都被假定与大麻成瘾严重程度的增加(即更多的强迫使用和更多的负面后果)有关，但与一生累积的大麻使用量关系不大。在记忆表现方面，预计会出现相反的情况。更多地了解神经心理功能和大麻成瘾之间的联系，将有助于澄清与它们的时间关联有关的理论模型。在临床上，更多地了解成瘾的神经心理学预测因素和后遗症将有助于我们开发更有针对性和量身定做的干预和预防计划，与NIDA的目标一致。重要的是，我们的发现将澄清决策是大麻使用和成瘾的先行风险因素，还是使用的结果，或者两者兼而有之。 与公共健康相关：吸食大麻的人有时会表现出记忆力和大脑做出正确决策的方式的障碍。这项研究将有助于确定决策问题是否是一些青少年对大麻上瘾的原因之一。它还将描述从实验性使用大麻到上瘾的进展如何影响记忆和决策。更多地了解大麻成瘾的预测因素将有助于我们为青少年制定具体的干预和预防计划。

DESCRIPTION (provided by applicant): More people in the United States are addicted to cannabis than to any other illicit drug, and prevalence of its use is rising, accompanied by a decline in the disapproval of its use and its perceived harm among adolescents. Important maturational changes in prefrontal cortex during adolescence may make youth more vulnerable than adults to adverse effects from cannabis. Indeed, research shows impairments in memory performance and decision-making abilities of heavy cannabis users, most of whom initiate use during adolescence. However, little is known about how decision-making and memory are affected across the trajectory from initial experimentation to development of cannabis addiction. Furthermore, there is controversy in the scientific literature on whether the impairments in decision-making observed among heavy cannabis users are due to the harmful effects of cannabis on brain functioning, or whether they may be an antecedent risk factor for the development of cannabis addiction. The principal goals of this proposal are to determine whether: a) decision-making is an antecedent risk factor for cannabis addiction; and b) what changes occur in decision-making and episodic memory along different cannabis use trajectories. Participants will be 400 youth ages 14 to 16 at baseline, most of whom will have experimented with cannabis, but have yet to develop addiction. Over two years, their performance will be assessed on measures of decision-making and episodic memory every 12 months and on their substance use and symptoms of cannabis addiction every 6 months. Poorer decision-making at baseline is hypothesized to be associated with increased risk of developing cannabis addiction during follow-up. Those who escalate in their cannabis consumption over time will show greater deterioration in their episodic memory than observed in other (non-escalating or desisting) cannabis use trajectories. In contrast, decision-making will show little change across all trajectories, consistent with its hypothesized role as an antecedent, rather than a consequence, of cannabis addiction. Any declines observed in decision-making during follow-up are hypothesized to be associated with increased severity of cannabis addiction (i.e., more compulsive use and more negative consequences), but less so with cumulative lifetime amounts of cannabis use. The opposite pattern is expected with memory performances. Understanding more about the links between neuropsychological functions and cannabis addiction will help clarify theoretical models pertaining to their temporal association. Clinically, knowing more about neuropsychological predictors and sequelae of addiction will help us to develop more targeted and tailored interventions and prevention programs, consistent with NIDA's goals. Importantly, our findings will clarify whether decision-making is an antecedent risk factor for cannabis use and addiction, a consequence of use, or both. PUBLIC HEALTH RELEVANCE: People who use marijuana sometimes show impairments in their memory and in the way that their brain makes good decisions. This study will help to determine if problems with decision-making are one of the reasons that some teens become addicted to marijuana. It will also describe how progressing from experimental marijuana use to addiction affects memory and decision-making. Knowing more about predictors of marijuana addiction will help us to develop specific interventions and prevention programs for teens.