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

描述(申请人提供)：尽管大麻的使用与鲁莽驾驶、性传播疾病和艾滋病毒等冒险行为有关，但关于大麻对冒险和冲动的严重影响的受控研究有限，而且大麻可能增加此类行为的机制尚未建立。德尔塔-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自制力的预期都可能导致受控认知过程中的缺陷，对负面后果的忽视，以及随后在大麻影响下冒险行为的增加。平衡安慰剂设计(BPD)是确定药理效应的最佳方法，与被告知药物被消费的预期效应无关。与酒精和尼古丁bpd的研究相比，关于毒品预期对行为的影响的研究很少。这一新的研究者R01的主要假设是，药理效应和大麻预期操纵将独立地a)在计算机风险承担指标上增加冒险倾向，b)增加延迟奖励的折扣，c)降低在两个冲动指标上抑制优势反应的能力，以及d)在行为和自我报告指标上增加对性风险的预期参与。在2(指导组：已告知THC与已告知无THC)×2(药物给药：有THC的大麻与安慰剂)的受试者之间的BPD中，我们将检验中等剂量(2.5%)的THC的药理效应，而不考虑大麻的预期在这些措施上的124个非依赖的18-25岁。吸食大麻者。个人将在基线/非吸烟条件下进行测试，并随机分配到每日4桶条件中的一种，一周后在大麻/安慰剂条件下进行测试。DNA样本将被收集用于CNR1基因的候选基因分型，这可能会产生关于THC药理效应的额外信息。这项研究首次评估了大麻药理和预期的独立作用，这可能有助于理解大麻与高危行为的关联。外行描述：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做出冲动决定的过程，因为它将实际的药物效应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.