What determines an individual's vulnerability to the harmful effects of cannabis?

曾经使用过大麻的年轻人患精神分裂症等精神障碍的风险增加40%；在大量使用的人群中，风险增加了200%。现在寻求大麻成瘾治疗的年轻人数量也在迅速增加。《泰晤士报》最近在英国的标题是：？每周有500名大麻吸食者寻求医疗帮助？（2008年1月11日）。此外，大麻对大脑的影响引起了人们的担忧，即使用这种药物的年轻人可能在教育或工作中表现不佳。我们不做什么？我还不明白为什么有些人使用大麻几乎没有明显的有害影响，而另一些人却患上了精神疾病或上瘾，或者注意力集中和记忆力出现问题。在同类研究中，我们最近首次发现，年轻人吸食的大麻中的两种主要成分（四氢大麻酚和CBD）会影响他们在日常生活中经历的类似精神病的影响。拟议的研究建立在这一发现和我们最近对244名年轻人进行的评估大麻影响的大规模研究的基础上。它旨在确定哪些大麻相关因素和哪些个人因素使一些年轻人容易受到毒品的有害影响。它解决的三个主要危害是精神病样症状、成瘾和认知障碍。研究的第一阶段将是自然主义的，涉及600名16-23岁的年轻人，他们的大麻使用情况不同。一些大麻使用者将被选择进入第二阶段——对大麻的两种主要成分（四氢大麻酚和CBD）单独和联合的影响进行控制的实验室研究。在这两个阶段，我们将评估的影响是类似精神病的，与成瘾有关的和认知的。我们也会调查年轻人。美国人对不同种类大麻的信仰和看法，比如臭鼬大麻和辛香大麻。在撰写本提案时，政府正在等待对大麻分类进行另一次审查的结果。这是否会导致大麻从C类提升到B类，对大麻使用者的影响可以忽略不计。如果我们证明，如果脆弱的青少年选择CBD含量较高的品种，或者服用CBD补充剂，有害影响可以减少，那么这可能会导致一个更安全使用大麻的新时代。重要的是，它可以显著减少英国目前被诊断为精神分裂症的年轻人的数量，如果他们没有使用这种药物，他们就不会患上精神疾病。

A young person who has ever used cannabis has a 40% increased risk of developing a psychotic disorder like schizophrenia; in those using heavily, the increased risk can be 200%. There are also rapidly growing numbers of young people now seeking treatment for cannabis addiction. The Times recently headlined that in England: ?500 cannabis smokers a week seek medical help? (January 11th, 2008). Further, the effects of cannabis on the brain raise concerns that young people who use this drug may under-achieve in education or work. What we don?t yet understand is why some individuals can use cannabis with few apparent harmful effects whereas others become mentally ill or addicted or have problems concentrating and remembering. In the first research of its kind, we recently discovered that two main constituents (THC and CBD) in the cannabis that young people smoke influence the psychotic-like effects they experience in everyday life. The proposed research builds on this finding and on our recent large-scale study with 244 young people assessing the effects of cannabis. It aims to determine which cannabis-related and which individual factors make some young people vulnerable to the harmful effects of the drug. The three main harms it addresses are psychotic-like symptoms, addiction and cognitive impairment. The first phase of the study will be naturalistic and involve 600 16-23 year olds who differ in their cannabis use. Some cannabis users will be selected for Phase 2 - a controlled, laboratory study of the effects of two main constituents of cannabis (THC and CBD) both alone and combined. In both Phases, the effects we will assess are psychotic-like, addiction-related and cognitive. We will also investigate young people?s beliefs and views about different strains of cannabis, such as skunk and sinsemilla. At the time of writing this proposal, the Government is waiting for findings of yet another review of the classification of cannabis. Whether or not this results in it being raised from Class C to B will have negligible impact on cannabis users.If we show that the harmful effects can be reduced if vulnerable youngsters choose strains with higher CBD content, or if they take CBD supplements, then this could lead to a new era of safer cannabis use. Importantly, it could significantly reduce the numbers of young people in the UK currently diagnosed schizophrenic who would not have become mentally ill if they had not used this drug.