Marijuana's Acute Effects on Risk Taking, Sexual/HIV risk, and Impulsivity

描述（由申请人提供）：尽管大麻的使用和冒险行为之间的关联，包括鲁莽驾驶，性传播疾病和艾滋病毒，大麻对冒险和冲动的急性影响的控制研究是有限的，大麻可能增加这种行为的机制尚未建立。δ-9-四氢大麻酚（THC）的药理作用和大麻损害判断力或使人失去抑制的预期都可能导致受控认知过程的缺陷，负面后果的折扣，以及随后在大麻影响下冒险的增加。平衡安慰剂设计（BPD）是确定药理学效应的最佳方法，与被告知药物已被消耗的预期效应无关。与酒精和尼古丁BPD的研究相反，很少有关于大麻对药物预期对行为影响的研究。在这个新的研究者R 01中的主要假设是药理学效应和大麻期望操纵将独立地a）增加对风险承担的计算机化测量的风险承担倾向，B）增加延迟奖励的折扣，c）降低抑制对两个冲动性测量的优势反应的能力，以及d）增加对行为和自我报告测量的性风险的预期参与。在2（指导集：告诉THC与告诉没有THC）× 2（药物管理：大麻与THC与安慰剂）受试者之间的BPD中，我们将检查中等（2.5%）剂量THC的药理学作用，独立于大麻预期对124名非依赖性18-25岁的受试者的这些措施。吸食大麻的人个体将在基线/不吸烟条件下进行测试，并随机分配到4种BPD条件之一中，1周后在大麻/安慰剂下进行测试。将收集DMA样本用于CNR 1基因的候选基因分型，这可能会产生关于THC药理作用的额外信息。这项研究是第一个评估大麻药理学和预期的独立影响，这可能有助于理解大麻与高风险行为的关联。通俗描述：我们需要了解为什么人们在使用大麻时会冒更多的风险，比如吸毒驾驶或参与不安全的性行为。这项研究可能有助于理解冒险和冲动决定的过程，通过将实际的药物效果与安慰剂和对大麻的信念分开。

DESCRIPTION (provided by applicant): Despite associations between marijuana use and risk-taking behaviors including reckless driving, sexually transmitted diseases and HIV, controlled research on marijuana's acute effects on risk taking and impulsivity is limited, and the mechanism whereby marijuana may increase such behaviors has not been established. Both the pharmacologic effect of delta-9-tetrahydrocannabinol (THC) and the expectancy that marijuana impairs judgment or makes one disinhibited may lead to deficits in controlled cognitive processing, discounting of negative consequences, and subsequent increases in risk taking under the influence of marijuana. The balanced-placebo design (BPD) is the optimal method for determining pharmacologic effects independent of the expectancy effects of being told that drug was consumed. In contrast to research with alcohol and nicotine BPD, there is little research with marijuana on effects of drug expectancy on behavior. The primary hypotheses in this new investigator R01 are that both the pharmacologic effect and marijuana expectancy manipulation will independently a) increase propensity to take risks on a computerized measure of risk taking, b) increase discounting of delayed rewards, c) decrease ability to inhibit prepotent responses on two impulsivity measures, and d) increase expected involvement in sexual risk on behavioral and self- report measures. In a 2 (instructional set: told THC vs. told no THC) X 2 (drug administration: marijuana with THC vs. placebo) between-subjects BPD, we will examine the pharmacologic effect of a moderate (2.5%) dose of THC independent of marijuana expectancies on these measures with 124 nondependent 18-25 y.o. marijuana smokers. Individuals will be tested under baseline/no smoking condition and randomly assigned to one of 4 BPD conditions to be tested under marijuana/placebo 1 week later. DMA samples will be collected for candidate genotyping of the CNR1 gene, which may yield additional information on the pharmacologic effect of THC. This study is the first to evaluate the independent effects of marijuana pharmacology and expectancies, which may facilitate the understanding of marijuana's association with high risk behaviors. Lay description: We need to understand why people take more risks such as drug driving or involvement in unsafe sex when using marijuana. This research may help understand the process of risk taking and making impulsive decisions by separating the actual drug effects from those of placebo and beliefs about marijuana.