Abstract

Objective

Substance abuse is common among patients with schizophrenia, is related to worse course and outcome of illness. Unfortunately, little is known about how substance abuse affects the cognitive function of schizophrenia patients, whose cognitive function is often already comprised. Neurocognitive functioning includes inhibition control and decision-making, and both schizophrenia and substance use disorder are related to impairments of inhibition control. However, the influence of substance abuse on inhibition capacities among schizophrenia patients is unclear. Methods: This study measured the influence of substance use disorder on inhibition capacities and risky decision-making in a group of 39 schizophrenia patients that were evaluated using a socio-demographic questionnaire and clinical assessment using the Positive and Negative Syndromes Scale for Schizophrenia. To assess inhibition control we utilized the Matching Familiar Figure Test (MFFT) and the Stroop task, and to evaluate decision-making we used the Iowa Gambling Task (IGT) and self-report questionnaire, the Barratt Impulsiveness Scale. Results: Univariate analysis found significant differences between the groups with regard to criminal history (χ2 = 5.97, p=.015), smoking status (χ2 = 12.30, p<.001), and total BIS score (t= −2.69, df = 37, p=.01). Our model did not find a significant effect of substance abuse on the first response time and number of errors on the MFFT or in the total interference index of Stroop performance and net score on risky decision-making in the IGT. The two groups did not differ significantly either in first response time or in number of errors on the MFFT (F = 0.54, p=.47, d = 0.24, 95% CI [-0.4, 0.88]; F = 0.28, p=.60, d = 0.61, 95% CI [0, 1.26], respectively), nor did they differ in the total interference index of the Stroop task (F(1)=0.49, p=.49, d = 0.25, 95% CI [-0.38, 0.88]). Conclusion: The analyses did not detect any statistically significant effect of substance abuse on inhibition control or risky decision-making processes in outpatients diagnosed with schizophrenia, despite increased impulsivity, criminal history and smoking status. These results neither support nor disprove previous findings.

中文翻译：

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药物滥用对一组门诊精神分裂症患者抑制能力和风险决策的影响

摘要

客观的

物质滥用在精神分裂症患者中很常见，与病情恶化的过程和结果有关。不幸的是，人们对药物滥用如何影响精神分裂症患者的认知功能知之甚少，他们的认知功能通常已经包含在内。神经认知功能包括抑制控制和决策，精神分裂症和物质使用障碍都与抑制控制受损有关。然而，药物滥用对精神分裂症患者抑制能力的影响尚不清楚。方法：本研究测量了物质使用障碍对 39 名精神分裂症患者的抑制能力和风险决策的影响，这些患者使用社会人口调查问卷和使用精神分裂症阳性和阴性综合征量表的临床评估进行评估。为了评估抑制控制，我们使用了匹配熟悉图形测试 (MFFT) 和 Stroop 任务，并使用了爱荷华州赌博任务 (IGT) 和自我报告问卷，即 Barratt 冲动量表来评估决策。结果：单变量分析发现，在犯罪史 ( χ2 = 5.97, p =.015)、吸烟状况 ( χ 2 = 12.30, p<.001) 和 BIS 总分 ( t = -2.69, df  = 37, p =.01)。我们的模型没有发现药物滥用对 MFFT 的首次响应时间和错误数量或 Stroop 性能的总干扰指数和 IGT 中风险决策的净得分有显着影响。两组在首次响应时间或 MFFT 错误数量上没有显着差异（F  = 0.54，p =.47，d  = 0.24，95% CI [-0.4，0.88]；F  = 0.28，p = .60, d  = 0.61, 95% CI [0, 1.26], 分别），在 Stroop 任务的总干扰指数（F(1)=0.49, p =.49, d  = 0.25, 95% CI [-0.38, 0.88])。结论：尽管冲动性、犯罪史和吸烟状况增加，但分析并未发现药物滥用对诊断为精神分裂症的门诊患者的抑制控制或风险决策过程有任何统计学意义的影响。这些结果既不支持也不反驳先前的发现。