Salience attribution and its relationship to cannabis-induced psychotic symptoms.
Salience attribution and its relationship to cannabis-induced psychotic symptoms.
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DOI：
10.1017/s0033291716002051
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发表时间：
2016-12
影响因子：
6.9
通讯作者：
Howes, O. D.
中科院分区：
文献类型：
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作者：
Bloomfield, M. A. P.;Mouchlianitis, E.;Morgan, C. J. A.;Freeman, T. P.;Curran, H. V.;Roiser, J. P.;Howes, O. D.
大麻是一种广泛使用的药物，与精神病风险增加有关。精神病的多巴胺假说假设显着性处理的改变会导致精神病。因此，我们测试了大麻使用者表现出异常显着性的假设，并探讨了异常显着性与多巴胺合成能力之间的关系。我们使用显着性归因测试（一项概率奖励学习任务）测试了 17 名大麻使用者和 17 名年龄和性别匹配的非使用者对照。在使用者中，大麻引起的精神病症状是通过拟心理状态量表进行测量的。使用 3,4-二羟基-6-[18F]氟-1-苯丙氨酸正电子发射断层扫描对 10 名用户和 6 名对照者测量了多巴胺合成能力，以流入速率常数 Kicer 为索引。各组之间的异常显着性没有显着差异[F1,32 = 1.12，p = 0.30（隐式）； F1,32 = 1.09，p = 0.30（显式）]。在使用者中，大麻引起的精神病症状严重程度与显性异常显着性评分之间存在显着正相关（r = 0.61，p = 0.04），并且大麻依赖/滥用状态与高隐性异常显着性评分之间存在显着相关性（F1,15 = 5.8，p = 0.03）。在对照组中，隐性异常显着性与整个纹状体多巴胺合成能力呈负相关（r = -0.91，p = 0.01），而这种关系在用户中不显着（相关性之间的差异：Z = -2.05，p = 0.04）。异常显着性与大麻引起的精神病症状严重程度呈正相关，但在大麻使用者中并未观察到。这与大麻使用和精神病之间的联系涉及显着性处理的改变的假设是一致的。需要进行纵向研究来确定这些认知异常是否是预先存在的或由长期使用大麻引起的。
Cannabis is a widely used drug associated with increased risk for psychosis. The dopamine hypothesis of psychosis postulates that altered salience processing leads to psychosis. We therefore tested the hypothesis that cannabis users exhibit aberrant salience and explored the relationship between aberrant salience and dopamine synthesis capacity. We tested 17 cannabis users and 17 age- and sex-matched non-user controls using the Salience Attribution Test, a probabilistic reward-learning task. Within users, cannabis-induced psychotic symptoms were measured with the Psychotomimetic States Inventory. Dopamine synthesis capacity, indexed as the influx rate constant Kicer, was measured in 10 users and six controls with 3,4-dihydroxy-6-[18F]fluoro-l-phenylalanine positron emission tomography. There was no significant difference in aberrant salience between the groups [F1,32 = 1.12, p = 0.30 (implicit); F1,32 = 1.09, p = 0.30 (explicit)]. Within users there was a significant positive relationship between cannabis-induced psychotic symptom severity and explicit aberrant salience scores (r = 0.61, p = 0.04) and there was a significant association between cannabis dependency/abuse status and high implicit aberrant salience scores (F1,15 = 5.8, p = 0.03). Within controls, implicit aberrant salience was inversely correlated with whole striatal dopamine synthesis capacity (r = −0.91, p = 0.01), whereas this relationship was non-significant within users (difference between correlations: Z = −2.05, p = 0.04). Aberrant salience is positively associated with cannabis-induced psychotic symptom severity, but is not seen in cannabis users overall. This is consistent with the hypothesis that the link between cannabis use and psychosis involves alterations in salience processing. Longitudinal studies are needed to determine whether these cognitive abnormalities are pre-existing or caused by long-term cannabis use.