King's College London, Department of Psychosis Studies, Institute of Psychiatry, London, UK.
King's College London, Department of Psychosis Studies, Institute of Psychiatry, London, UK.
Lancet. 2015 Feb 26;385 Suppl 1:S79. doi: 10.1016/S0140-6736(15)60394-4.
Cannabis is frequently used among individuals with first episode psychosis and is associated with poor clinical outcomes. However, little is known about the effect of cannabis use on the response to antipsychotic medications and how use could affect outcomes. Using natural language processing on clinical data from a large electronic case register, we sought to investigate whether resistance to antipsychotic treatment mediated poor clinical outcomes associated with cannabis use.
Data were obtained from 2026 people with first episode psychosis in south London, UK. Cannabis use documented in free text clinical records was identified with natural language processing. Data for age, sex, ethnicity, marital status, psychotic disorder diagnosis, subsequent hospital admission, and number of unique antipsychotic medications prescribed were obtained using the Clinical Record Interactive Search instrument. The association of these variables with cannabis use was analysed with multivariable regression and mediation analysis.
939 people (46·3%) with first episode psychosis were using cannabis at first presentation. Cannabis use was most strongly associated with being 16-25 years old, male, and single, and was also associated with an increase in number of hospital admissions (incidence rate ratio 1·50, 95% CI 1·25-1·80), compulsory hospital admission (odds ratio 1·55, 1·16-2·08), and number of days spent in hospital (β coefficient 35·1 days, 12·1-58·1) over 5 years' follow-up. An increase in number of unique antipsychotic medications mediated an increase in number of hospital admissions (natural indirect effect 1·11, 1·04-1·17; total effect 1·41, 1·22-1·64), compulsory hospital admission (1·27, 1·10-1·45; 1·71, 1·05-2·78), and number of days spent in hospital (16·1, 6·7-25·5; 19·9, 2·5-37·3).
We showed that a substantial number of people with first episode psychosis used cannabis and that its use was associated with increased likelihood of hospital admission and number of days spent in hospital. These associations were partly mediated by an increase in number of unique antipsychotic medications prescribed. These findings suggest that cannabis might reduce response to conventional antipsychotic treatment and highlight the importance of strategies to reduce its use.
National Institute for Health Research, UK Medical Research Council.
大麻在首发精神分裂症患者中经常被使用，并与不良临床结局相关。然而，对于大麻使用对抗精神病药物治疗反应的影响以及使用如何影响结局，我们知之甚少。本研究使用自然语言处理方法对来自英国伦敦南部一个大型电子病例登记处的临床数据进行分析，旨在调查抗精神病药物治疗抵抗是否在大麻使用相关的不良临床结局中起中介作用。
研究纳入了 2026 名首发精神分裂症患者，数据来源于英国伦敦南部的一个电子病例登记处。通过自然语言处理方法识别出病历记录中的大麻使用情况。使用临床记录交互式搜索工具（Clinical Record Interactive Search）获取年龄、性别、种族、婚姻状况、精神障碍诊断、随后的住院情况以及开具的独特抗精神病药物数量等数据。使用多变量回归和中介分析来分析这些变量与大麻使用之间的关联。
939 名（46.3%）首发精神分裂症患者在首发时使用大麻。大麻使用与年龄 16-25 岁、男性和单身的相关性最强，且与住院人数增加（发病率比 1.50，95%CI 1.25-1.80）、强制住院（比值比 1.55，1.16-2.08）和 5 年随访期间住院天数（β系数 35.1 天，12.1-58.1）增加相关。独特抗精神病药物数量的增加介导了住院人数的增加（自然间接效应 1.11，1.04-1.17；总效应 1.41，1.22-1.64）、强制住院（1.27，1.10-1.45；1.71，1.05-2.78）和住院天数（16.1，6.7-25.5；19.9，2.5-37.3）增加。
我们发现，相当数量的首发精神分裂症患者使用大麻，且其使用与住院可能性增加和住院天数增加相关。这些关联部分是由开具的独特抗精神病药物数量增加介导的。这些发现表明，大麻可能会降低对常规抗精神病药物治疗的反应，并强调了减少其使用的策略的重要性。
英国国民健康保险制度，英国医学研究理事会。
