Centre for Research on Ageing, Health and Wellbeing, Australian National University, Building 54, Mills Road, Acton, ACT 2601, Australia.
St Vincent's Hospital, 41 Victoria Parade, Fitzroy, VIC 3065, Australia; Department of Psychiatry, University of Melbourne, Grattan St, Melbourne, VIC 3010, Australia.
Compr Psychiatry. 2019 Aug;93:27-32. doi: 10.1016/j.comppsych.2019.06.002. Epub 2019 Jun 28.
Positive psychotic symptoms have consistently been associated with methamphetamine use but the presence of a negative symptom cluster remains unclear. We used exploratory factor analysis to examine whether a discrete negative syndrome could be delineated among methamphetamine users, and to examine the clinical correlates of this syndrome.
Participants (N = 154) were people who used methamphetamine at least monthly and did not meet DSM-IV diagnostic criteria for lifetime schizophrenia. Scores on the Brief Psychiatric Rating Scale for the past month were subject to exploratory factor analysis. Latent class analysis was applied to resultant factor scores to determine whether negative and positive factors were experienced by the same participants. Past-month substance use measures were days of use for each drug type and methamphetamine dependence assessed using the Severity of Dependence Scale.
We articulated a three-factor model including 'positive/activation symptoms' (e.g. suspiciousness, hallucinations, conceptual disorganisation, tension), 'affective symptoms' (e.g. depression, anxiety) and 'negative symptoms' (e.g. blunted affect, motor retardation). Positive-activation and affective symptoms (but not negative symptoms) were positively correlated with past month days of methamphetamine use (r = 0.16; r = 0.25) and severity of dependence (r = 0.24; r = 0.41). Negative symptoms were correlated with heroin (r = 0.24) and benzodiazepine use (r = 0.21). Latent class analysis revealed a three-class model comprising a positive-symptom class (44%, high positive-activation, low negative symptoms), a negative-symptom class (31%, low positive-activation, high negative symptoms), and a low-symptom class (38%, low on all factors).
A negative symptom syndrome exists among people who use methamphetamine, but this appears related to polysubstance use rather than forming a part of the psychotic syndrome associated with methamphetamine use. Overlooking the role of polysubstance use on negative symptoms may conflate the profiles of methamphetamine-associated psychosis and schizophrenia.
阳性精神病症状一直与甲基苯丙胺的使用有关，但阴性症状群的存在仍不清楚。我们使用探索性因子分析来检验在甲基苯丙胺使用者中是否可以描绘出一个离散的阴性综合征，并检验该综合征的临床相关性。
参与者（N=154）是至少每月使用一次甲基苯丙胺且不符合 DSM-IV 终身精神分裂症诊断标准的人。对过去一个月的简明精神病评定量表评分进行探索性因子分析。潜在类别分析应用于所得因子得分，以确定阳性和阴性因子是否由同一参与者经历。过去一个月的药物使用测量包括每种药物类型的使用天数和使用严重程度依赖量表评估的甲基苯丙胺依赖程度。
我们提出了一个三因素模型，包括“阳性/激活症状”（如怀疑、幻觉、概念混乱、紧张）、“情感症状”（如抑郁、焦虑）和“阴性症状”（如情感迟钝、运动迟缓）。阳性/激活症状和情感症状（但不是阴性症状）与过去一个月的甲基苯丙胺使用天数（r=0.16；r=0.25）和依赖严重程度（r=0.24；r=0.41）呈正相关。阴性症状与海洛因（r=0.24）和苯二氮䓬类药物（r=0.21）的使用相关。潜在类别分析显示出一个三类别模型，包括一个阳性症状类别（44%，高阳性激活，低阴性症状）、一个阴性症状类别（31%，低阳性激活，高阴性症状）和一个低症状类别（38%，所有因素均低）。
在使用甲基苯丙胺的人群中存在阴性症状综合征，但这似乎与多药物使用有关，而不是构成与甲基苯丙胺使用相关的精神病综合征的一部分。忽视多药物使用对阴性症状的作用可能会混淆与甲基苯丙胺相关的精神病和精神分裂症的特征。
