全球每年约有1.88亿人使用大麻。它最近在美国11个州合法化,加拿大,和乌拉圭用于娱乐。大麻使用增加的潜力凸显了需要更好地了解其风险,包括精神病和其他精神症状的急性诱导。我们旨在研究与安慰剂相比,单独使用大麻成分Δ9-四氢大麻酚(THC)以及与大麻二酚(CBD)联合使用对健康人精神症状的影响。
在这篇系统综述和荟萃分析中,我们搜索了MEDLINE,Embase,和PsycINFO,用于在数据库开始到2019年5月21日之间以英语发表的研究,交叉设计。纳入标准是在急性静脉注射后使用精神病学量表(简短精神病学评定量表[BPRS]和阳性和阴性综合征量表[PANSS])报告症状的研究,口服,或鼻THC,CBD,健康参与者的安慰剂,并提供允许计算阳性(包括妄想和幻觉)的标准化平均变化(SMC)分数的数据,消极(如迟钝的情感和动机),和一般(包括抑郁和焦虑)症状。我们进行了随机效应荟萃分析,以评估总效应大小的主要结果,积极的,与安慰剂相比,THC给药后健康参与者的PANSS和BPRS评分为阴性。因为对CBD的调节作用进行荟萃分析的研究数量不足,仅对这一结果进行了系统审查.这项研究在PROSPERO注册,CRD42019136674。
确定了15项涉及THC急性给药的合格研究和4项关于CBD加THC给药的研究。与安慰剂相比,THC显着增加总症状严重程度,具有较大的效应大小(在9项研究中评估,有十个独立的样本,涉及196名参与者:SMC1·10[95%CI0·92-1·28],p<0·0001);阳性症状严重程度(在14项研究中评估,有15个独立样本,涉及324名参与者:SMC0·91[95%CI0·68-1·14],p<0·0001);以及具有较大效应大小的阴性症状严重程度(在12项研究中评估,有13个独立样本,涉及267名参与者:SMC0·78[95%CI0·59-0·97],p<0·0001)。在系统审查中,在评估CBD对THC诱导症状的影响的四项研究中,只有一个人发现症状明显减轻。
单一THC给药诱导精神病,负,和其他具有大效应的精神症状。没有一致的证据表明CBD会诱发症状或减轻THC的影响。这些发现强调了与使用含有THC的大麻和其他大麻素用于娱乐或治疗目的相关的潜在风险。
英国医学研究委员会,Maudsley慈善机构,大脑和行为研究基金会,惠康信托基金,和英国国家健康研究所。
Approximately 188 million people use cannabis yearly worldwide, and it has recently been legalised in 11 US states, Canada, and Uruguay for recreational use. The potential for increased cannabis use highlights the need to better understand its risks, including the acute induction of psychotic and other psychiatric symptoms. We aimed to investigate the effect of the cannabis constituent Δ9-tetrahydrocannabinol (THC) alone and in combination with cannabidiol (CBD) compared with placebo on psychiatric symptoms in healthy people.
In this systematic
review and meta-analysis, we searched MEDLINE, Embase, and PsycINFO for studies published in English between database inception and May 21, 2019, with a within-person, crossover design. Inclusion criteria were studies reporting symptoms using psychiatric scales (the Brief Psychiatric Rating Scale [BPRS] and the Positive and Negative Syndrome Scale [PANSS]) following the acute administration of intravenous, oral, or nasal THC, CBD, and placebo in healthy participants, and presenting data that allowed calculation of standardised mean change (SMC) scores for positive (including delusions and hallucinations), negative (such as blunted affect and amotivation), and general (including depression and anxiety) symptoms. We did a random-effects meta-analysis to assess the main outcomes of the effect sizes for total, positive, and negative PANSS and BPRS scores measured in healthy participants following THC administration versus placebo. Because the number of studies to do a meta-analysis on CBD\'s moderating effects was insufficient, this outcome was only systematically reviewed. This study is registered with PROSPERO, CRD42019136674.
15 eligible studies involving the acute administration of THC and four studies on CBD plus THC administration were identified. Compared with placebo, THC significantly increased total symptom severity with a large effect size (assessed in nine studies, with ten independent samples, involving 196 participants: SMC 1·10 [95% CI 0·92-1·28], p<0·0001); positive symptom severity (assessed in 14 studies, with 15 independent samples, involving 324 participants: SMC 0·91 [95% CI 0·68-1·14], p<0·0001); and negative symptom severity with a large effect size (assessed in 12 studies, with 13 independent samples, involving 267 participants: SMC 0·78 [95% CI 0·59-0·97], p<0·0001). In the systematic
review, of the four studies evaluating CBD\'s effects on THC-induced symptoms, only one identified a significant reduction in symptoms.
A single THC administration induces psychotic, negative, and other psychiatric symptoms with large effect sizes. There is no consistent evidence that CBD induces symptoms or moderates the effects of THC. These findings highlight the potential risks associated with the use of cannabis and other cannabinoids that contain THC for recreational or therapeutic purposes.
UK Medical Research Council, Maudsley Charity, Brain and Behavior Research Foundation, Wellcome Trust, and the UK National Institute for Health Research.