Large Matthew, Sharma Swapnil, Compton Michael T, Slade Tim, Nielssen Olav
Mental Health Service, Prince of Wales Hospital, Sydney, Australia.
Arch Gen Psychiatry. 2011 Jun;68(6):555-61. doi: 10.1001/archgenpsychiatry.2011.5. Epub 2011 Feb 7.
A number of studies have found that the use of cannabis and other psychoactive substances is associated with an earlier onset of psychotic illness.
To establish the extent to which use of cannabis, alcohol, and other psychoactive substances affects the age at onset of psychosis by meta-analysis.
Peer-reviewed publications in English reporting age at onset of psychotic illness in substance-using and non-substance-using groups were located using searches of CINAHL, EMBASE, MEDLINE, PsycINFO, and ISI Web of Science.
Studies in English comparing the age at onset of psychosis in cohorts of patients who use substances with age at onset of psychosis in non-substance-using patients. The searches yielded 443 articles, from which 83 studies met the inclusion criteria.
Information on study design, study population, and effect size were extracted independently by 2 of us.
Meta-analysis found that the age at onset of psychosis for cannabis users was 2.70 years younger (standardized mean difference = -0.414) than for nonusers; for those with broadly defined substance use, the age at onset of psychosis was 2.00 years younger (standardized mean difference = -0.315) than for nonusers. Alcohol use was not associated with a significantly earlier age at onset of psychosis. Differences in the proportion of cannabis users in the substance-using group made a significant contribution to the heterogeneity in the effect sizes between studies, confirming an association between cannabis use and earlier mean age at onset of psychotic illness.
The results of meta-analysis provide evidence for a relationship between cannabis use and earlier onset of psychotic illness, and they support the hypothesis that cannabis use plays a causal role in the development of psychosis in some patients. The results suggest the need for renewed warnings about the potentially harmful effects of cannabis.
多项研究发现，使用大麻和其他精神活性物质与精神病性疾病的更早发病有关。
通过荟萃分析确定使用大麻、酒精和其他精神活性物质对精神病发病年龄的影响程度。
通过检索护理及健康领域数据库（CINAHL）、荷兰医学文摘数据库（EMBASE）、医学期刊数据库（MEDLINE）、心理学文摘数据库（PsycINFO）和科学引文索引（ISI）科学网，查找以英文发表的、报告使用物质组和未使用物质组精神病性疾病发病年龄的同行评审出版物。
比较使用物质的患者队列与未使用物质的患者队列中精神病发病年龄的英文研究。检索得到443篇文章，其中83项研究符合纳入标准。
我们两人独立提取有关研究设计、研究人群和效应量的信息。
荟萃分析发现，大麻使用者的精神病发病年龄比未使用者年轻2.70岁（标准化均数差=-0.414）；对于广义定义的物质使用者，精神病发病年龄比未使用者年轻2.00岁（标准化均数差=-0.315）。饮酒与精神病发病年龄显著提前无关。使用物质组中大麻使用者比例的差异对各研究效应量的异质性有显著影响，证实了使用大麻与精神病性疾病更早的平均发病年龄之间存在关联。
荟萃分析结果为使用大麻与精神病性疾病更早发病之间的关系提供了证据，并支持大麻使用在某些患者精神病发展中起因果作用的假设。结果表明需要重新发出关于大麻潜在有害影响的警告。
