Shakoor Sania, Zavos Helena M S, McGuire Philip, Cardno Alastair G, Freeman Daniel, Ronald Angelica
Centre for Brain and Cognitive Development, Department of Psychological Sciences, Birkbeck, University of London, UK.
King׳s College London, MRC Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, UK.
Psychiatry Res. 2015 Jun 30;227(2-3):144-51. doi: 10.1016/j.psychres.2015.03.041. Epub 2015 Apr 14.
Cannabis users are more likely to have psychotic experiences (PEs). The degree to which these associations are driven by genetic or environmental influences in adolescence is unknown. This study estimated the genetic and environmental contributions to the relationship between cannabis use and PEs. Specific PEs were measured in a community-based twin sample (4830 16-year-old pairs) using self-reports and parent-reports. Adolescents reported on ever using cannabis. Multivariate liability threshold structural equation model-fitting was conducted. Cannabis use was significantly correlated with PEs. Modest heritability (37%), common environmental influences (55%) and unique environment (8%) were found for cannabis use. For PEs, modest heritability (27-54%), unique environmental influences (E=12-50%) and little common environmental influences (11-20%), with the exception of parent-rated Negative Symptoms (42%), were reported. Environmental influences explained all of the covariation between cannabis use and paranoia, cognitive disorganization and parent-rated negative symptoms (bivariate common environment=69-100%, bivariate unique environment=28-31%), whilst the relationship between cannabis use and hallucinations indicated familial influences. Cannabis use explains 2-5% of variance in positive, cognitive, and negative PEs. Cannabis use and psychotic experience co-occur due to environmental factors. Focus on specific environments may reveal why adolescent cannabis use and psychotic experiences tend to 'travel together'.
大麻使用者更有可能出现精神病体验（PEs）。在青少年时期，这些关联在多大程度上是由遗传或环境影响驱动的尚不清楚。本研究估计了遗传和环境因素对大麻使用与精神病体验之间关系的影响。使用自我报告和家长报告，在一个基于社区的双胞胎样本（4830对16岁双胞胎）中测量了特定的精神病体验。青少年报告了是否曾使用过大麻。进行了多变量责任阈值结构方程模型拟合。大麻使用与精神病体验显著相关。大麻使用的遗传度适中（37%），存在共同环境影响（55%）和独特环境影响（8%）。对于精神病体验，除家长评定的阴性症状（42%）外，报告的遗传度适中（27 - 54%），独特环境影响（E = 12 - 50%），共同环境影响较小（11 - 20%）。环境影响解释了大麻使用与偏执、认知紊乱和家长评定的阴性症状之间的所有协变（双变量共同环境 = 69 - 100%，双变量独特环境 = 28 - 31%），而大麻使用与幻觉之间的关系表明存在家族影响。大麻使用解释了阳性、认知性和阴性精神病体验中2 - 5%的方差。大麻使用和精神病体验同时出现是由于环境因素。关注特定环境可能会揭示为什么青少年大麻使用和精神病体验往往“相伴出现”。
