Department of Psychology, York University, Toronto, ON, Canada.
Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, United States; Institute for Addiction Science, University of Southern California, Los Angeles, CA, United States.
Drug Alcohol Depend. 2024 Oct 1;263:112417. doi: 10.1016/j.drugalcdep.2024.112417. Epub 2024 Aug 14.
Recent behavioural economic models of substance use suggest that low access to environmental reward may increase risk for heavy substance use and associated harms. Most prior studies of these associations have been cross-sectional and have focused on alcohol. The current study extends this research using longitudinal data to examine the within-person and between-person associations of environmental reward access with both alcohol and cannabis outcomes.
Young adults (N = 119, 64.71 % female) completed an online survey at three time points, spaced six months apart. The survey included measures of alcohol and cannabis use and consequences, and two facets of environmental reward access: reward probability (i.e., likelihood of experiencing environmental reward) and environmental suppression (i.e., diminished availability of environmental reward).
Multilevel models revealed that at the between-person level (i.e., averaged across time points), greater environmental suppression (but not reward probability) was significantly associated with more frequent cannabis use, and greater reward probability (but not environmental suppression) was significantly associated with heavier alcohol use. Higher environmental suppression (but not reward probability) was also associated with greater alcohol and cannabis consequences at the between-person level, over and above level of use. A significant within-person association also was observed, wherein participants reported relative increases in cannabis consequences during time periods when they also reported relative decreases in the availability of environmental reward.
Results highlight environmental suppression as a risk factor for more frequent cannabis use and for both alcohol and cannabis consequences, and provide novel support for a within-person association between environmental suppression and cannabis consequences over time. Findings may inform contextual interventions for young adult substance use.
最近的物质使用行为经济学模型表明，环境奖励的获取机会较低可能会增加重度物质使用和相关危害的风险。大多数关于这些关联的先前研究都是横断面研究，并且侧重于酒精。本研究使用纵向数据扩展了这项研究，以检查环境奖励获取与酒精和大麻结果的个体内和个体间关联。
年轻成年人（N=119，64.71%为女性）在三个时间点完成了在线调查，时间间隔为六个月。调查包括酒精和大麻使用和后果的测量，以及环境奖励获取的两个方面：奖励概率（即经历环境奖励的可能性）和环境抑制（即环境奖励的可用性降低）。
多层次模型显示，在个体间水平（即，在时间点平均值）上，更大的环境抑制（但不是奖励概率）与更频繁的大麻使用显著相关，而更大的奖励概率（但不是环境抑制）与更重的酒精使用显著相关。更高的环境抑制（但不是奖励概率）也与个体间更高的酒精和大麻后果相关，超过了使用水平。还观察到一个显著的个体内关联，即在参与者报告环境奖励的可用性相对减少的同时，他们也报告大麻后果相对增加。
结果突出了环境抑制作为更频繁的大麻使用以及酒精和大麻后果的风险因素，为环境抑制与大麻后果随时间的个体内关联提供了新的支持。研究结果可能为针对年轻成年人物质使用的情境干预提供信息。
