Clinical Psychopharmacology Unit, University College London, London, United Kingdom; Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom; NIHR University College London Hospitals Biomedical Research Centre, University College Hospital, London, United Kingdom.
Clinical Psychopharmacology Unit, University College London, London, United Kingdom.
Drug Alcohol Depend. 2022 Sep 1;238:109531. doi: 10.1016/j.drugalcdep.2022.109531. Epub 2022 Jun 9.
Adolescence is a period of psychological and neural development in which harms associated with cannabis use may be heightened. We hypothesised that adolescent who use cannabis (adolescentsWUC) would have steeper delay discounting (preference for immediate over future rewards) and greater demand (relative valuation) for cannabis than adults who use cannabis (adultsWUC).
This cross-sectional study, part of the 'CannTeen' project, compared adultsWUC (n = 71, 26-29 years old) and adolescentsWUC (n = 76, 16-17 years old), and gender- and age-matched adolescent (n = 63) and adult (n = 64) controls. AdolescentsWUC and adultsWUC used cannabis 1-7 days/week and were matched on cannabis use frequency (4 days/week). The Monetary Choice Questionnaire assessed delay discounting. A modified Marijuana Purchase Task (MPT) assessed cannabis demand in adolescentsWUC and adultsWUC. The MPT yielded five indices: intensity (amount of cannabis used at zero cost), O (total peak expenditure), P (price at peak expenditure), breakpoint (cost at which cannabis demand is suppressed to zero) and elasticity (degree to which cannabis use decreases with increasing price). Analyses were adjusted for covariates of gender, socioeconomic status, other illicit drug use.
Both adolescentsWUC and adultsWUC had steeper delay discounting than controls (F, (1,254)= 9.13, p = 0.003, η= 0.04), with no significant age effect or interaction. AdolescentsWUC showed higher intensity (F, (1,138)= 9.76, p = 0.002, η= 0.07) and lower elasticity (F, (1,138)= 15.25, p < 0.001, η= 0.10) than adultsWUC. There were no significant differences in P, O or breakpoint.
Individuals who use cannabis prefer immediate rewards more than controls. AdolescentsWUC, compared to adultsWUC, may be in a high-risk category with diminished sensitivity to cannabis price increases and a greater consumption of cannabis when it is free.
青春期是心理和神经发育的时期，在此期间，与大麻使用相关的危害可能会加剧。我们假设，与成年人相比，使用大麻的青少年（青少年 WCU）对大麻的延迟折扣（更偏好即时奖励而非未来奖励）和需求（相对价值）更高。
这是一项横断面研究，是“CannTeen”项目的一部分，比较了成年 WCU（n=71，26-29 岁）和青少年 WCU（n=76，16-17 岁），以及年龄和性别匹配的青少年（n=63）和成年（n=64）对照组。青少年 WCU 和成年 WCU 每周使用大麻 1-7 天，使用频率匹配（每周 4 天）。货币选择问卷评估了延迟折扣。改良的大麻购买任务（MPT）评估了青少年 WCU 和成年 WCU 对大麻的需求。MPT 产生了五个指数：强度（免费使用的大麻量）、O（总峰值支出）、P（峰值支出时的价格）、断点（抑制大麻需求至零时的成本）和弹性（随着价格的增加，大麻使用量的减少程度）。分析调整了性别、社会经济地位、其他非法药物使用的协变量。
青少年 WCU 和成年 WCU 的延迟折扣均比对照组更陡峭（F，（1，254）=9.13，p=0.003，η=0.04），且年龄效应或交互作用无显著差异。青少年 WCU 的强度较高（F，（1，138）=9.76，p=0.002，η=0.07），弹性较低（F，（1，138）=15.25，p<0.001，η=0.10）比成年 WCU。P、O 或断点无显著差异。
与对照组相比，使用大麻的个体更喜欢即时奖励。与成年 WCU 相比，青少年 WCU 可能处于高风险类别，对大麻价格上涨的敏感性降低，当大麻免费时，他们会消耗更多的大麻。
