School of Psychology and Ψ-P3: Centre for Psychophysics, Psychophysiology and Psychopharmacology, University of Wollongong, Wollongong, NSW Australia.
Int J Psychophysiol. 2013 Sep;89(3):381-9. doi: 10.1016/j.ijpsycho.2013.04.015. Epub 2013 Apr 28.
Chronic cannabis use has been associated with neurocognitive deficits, alterations in brain structure and function, and with psychosis. This study investigated the effects of chronic cannabis use on P50 sensory-gating in regular users, and explored the association between sensory gating, cannabis use history and the development of psychotic-like symptoms. Twenty controls and 21 regular cannabis users completed a P50 paired-click (S1 and S2) paradigm with an inter-pair interval of 9s. The groups were compared on P50 amplitude to S1 and S2, P50 ratio (S2/S1) and P50 difference score (S1-S2). While cannabis users overall did not differ from controls on P50 measures, prolonged duration of regular use was associated with greater impairment in sensory gating as indexed by both P50 ratio and difference scores (including after controlling for tobacco use). Long-term cannabis users were found to have worse sensory gating ratios and difference scores compared to short-term users and controls. P50 metrics did not correlate significantly with any measure of psychotic-like symptoms in cannabis users. These results suggest that prolonged exposure to cannabis results in impaired P50 sensory-gating in long-term cannabis users. While it is possible that these deficits may have pre-dated cannabis use and reflect a vulnerability to cannabis use, their association with increasing years of cannabis use suggests that this is not the case. Impaired P50 sensory-gating ratios have also been reported in patients with schizophrenia and may indicate a similar underlying pathology.
慢性大麻使用与神经认知缺陷、大脑结构和功能改变以及精神病有关。本研究调查了慢性大麻使用对定期使用者 P50 感觉门控的影响，并探讨了感觉门控、大麻使用史与类精神病症状发展之间的关联。20 名对照者和 21 名经常使用大麻者完成了 P50 配对点击（S1 和 S2）范式，间隔时间为 9 秒。对 P50 幅度对 S1 和 S2、P50 比值（S2/S1）和 P50 差值（S1-S2）进行了比较。虽然大麻使用者在 P50 测量上与对照组没有差异，但长期定期使用与感觉门控的损伤程度呈正相关，这两种指标均为 P50 比值和差值（包括控制吸烟量后）。与短期使用者和对照组相比，长期大麻使用者的 P50 指标比值和差值更差。在大麻使用者中，P50 指标与任何类精神病症状测量均无显著相关性。这些结果表明，长期接触大麻会导致长期大麻使用者的 P50 感觉门控受损。虽然这些缺陷可能先于大麻使用发生，反映了对大麻使用的易感性，但它们与使用大麻年限的增加有关，表明并非如此。精神分裂症患者也报告了 P50 感觉门控比值受损，这可能表明存在类似的潜在病理。
