Acute and chronic effects of cannabinoids on effort-related decision-making and reward learning: an evaluation of the cannabis 'amotivational' hypotheses
Acute and chronic effects of cannabinoids on effort-related decision-making and reward learning: an evaluation of the cannabis 'amotivational' hypotheses
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DOI：
10.1007/s00213-016-4383-x
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发表时间：
2016-10-01
影响因子：
3.4
通讯作者：
Curran, H. Valerie
中科院分区：
文献类型：
--
作者：
Lawn, Will;Freeman, Tom P.;Curran, H. Valerie
有趣的是，急性和慢性大麻使用都与冷漠，动机和其他奖励处理缺陷有关。到目前为止，对这些影响的经验支持是有限的，以前的研究没有评估δ-9-四氢大麻酚（THC）和大麻二酚（CBD）的急性影响，以及与大麻依赖的关联。本研究的目的是（1）检查大麻与CBD的急性影响（Cann + CBD）和无CBD（2）研究大麻依赖、努力相关决策和奖励学习之间的关联。在研究1中，17名参与者每人接受三种急性汽化治疗，即Cann-CBD（8 mg THC），Cann + CBD（8 mg THC + 10 mg CBD）和匹配的安慰剂，随后在1.5小时后补充50%剂量，并完成奖励任务的努力支出（EEfRT）。在第二项研究中，20名大麻依赖者与20名非依赖者进行了比较，药物使用对照参与者在非中毒状态下进行EEfRT和概率奖励任务（PRT）。相对于安慰剂，Cann-CBD降低了高努力选择的可能性与安慰剂（p = 0.014）和Cann + CBD（p = 0.006）相比，对预期值的敏感性增加。大麻依赖组和对照组在EEfRT上没有差异。然而，大麻依赖组在PRT上表现出比对照组更弱的反应偏差（p = 0.007）。大麻急性诱导了短暂的无动力状态，CBD影响了THC对预期值的影响。相比之下，大麻依赖与保留的动机以及受损的奖励学习有关，尽管包括抑郁症在内的混杂因素不能忽视。这是第一个动力良好，完全对照的研究，客观地证明了THC的急性失动作用。
Anecdotally, both acute and chronic cannabis use have been associated with apathy, amotivation, and other reward processing deficits. To date, empirical support for these effects is limited, and no previous studies have assessed both acute effects of Delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), as well as associations with cannabis dependence.The objectives of this study were (1) to examine acute effects of cannabis with CBD (Cann + CBD) and without CBD (Cann-CBD) on effort-related decision-making and (2) to examine associations between cannabis dependence, effort-related decision-making and reward learning.In study 1, 17 participants each received three acute vaporized treatments, namely Cann-CBD (8 mg THC), Cann + CBD (8 mg THC + 10 mg CBD) and matched placebo, followed by a 50 % dose top-up 1.5 h later, and completed the Effort Expenditure for Rewards Task (EEfRT). In study 2, 20 cannabis-dependent participants were compared with 20 non-dependent, drug-using control participants on the EEfRT and the Probabilistic Reward Task (PRT) in a non-intoxicated state.Cann-CBD reduced the likelihood of high-effort choices relative to placebo (p = 0.042) and increased sensitivity to expected value compared to both placebo (p = 0.014) and Cann + CBD (p = 0.006). The cannabis-dependent and control groups did not differ on the EEfRT. However, the cannabis-dependent group exhibited a weaker response bias than the control group on the PRT (p = 0.007).Cannabis acutely induced a transient amotivational state and CBD influenced the effects of THC on expected value. In contrast, cannabis dependence was associated with preserved motivation alongside impaired reward learning, although confounding factors, including depression, cannot be disregarded. This is the first well powered, fully controlled study to objectively demonstrate the acute amotivational effects of THC.