Premorbid IQ in schizophrenia: A meta-analytic review
Premorbid IQ in schizophrenia: A meta-analytic review
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DOI：
10.1176/appi.ajp.2008.07081242
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发表时间：
2008-05-01
影响因子：
17.7
通讯作者：
Seidman, Larry J.
中科院分区：
文献类型：
--
作者：
Woodberry, Kristen A.;Giuliano, Anthony J.;Seidman, Larry J.
目的：在过去的三十年里，精神分裂症的诊断标准发生了重大变化，智商的测量也发生了变化。上一次对精神分裂症患者病前智商的文献进行定量综述是在20多年前。从那时起，已经有许多关于这一问题的数据集的研究发表。本综述的目的是提供一个更新的荟萃分析发病前的智商在个人谁后来发展schizophrenia.Method：作者进行了系统的文献检索，产生了18项研究，符合荟萃分析的标准。入选标准是：1）在后来被诊断为精神分裂症、情感障碍或精神分裂样障碍的受试者中，发病前的智商心理测量，2）相似的比较数据，3）足够的数据用于计算效应量。模拟方差分析方法被用来模拟研究间方差，由于关键的研究设计features.Results：总体而言，精神分裂症样本表现出可靠的，中等大小的损害发病前智商。效应量的异质性很小，几乎完全是一项研究的结果。方法上的差异，如诊断标准，类型的智商测量，样本确定，和年龄在发病前的测试，有助于最小的效应量方差。对所有按年龄进行的研究进行横断面分析，并对在单一样本中使用重复测量智商的研究进行描述性审查，并不支持精神分裂症患者发病前智商相对下降。然而，所有在同一样本中进行发病前和发病后测试的研究都表明，精神分裂症患者的智商相对于对照组显著下降，与坦率精神病的发病有关。在精神病症状出现前几年，精神分裂症患者作为一个群体，显示平均IQ分数比健康对照受试者低约一半的标准差。
Objective: Over the past three decades, there have been significant changes in the diagnostic criteria for schizophrenia as well as changes in measurement of IQ. The last quantitative review of the literature on premorbid IQ in schizophrenia was published more than two decades ago. Since that time, there have been many published studies of data sets pertaining to this issue. The purpose of the present review was to provide an updated meta-analysis of premorbid IQ in individuals who later develop schizophrenia.Method: The authors performed a systematic literature search, which yielded 18 studies that met criteria for the meta-analysis. Inclusion criteria were 1) premorbid psychometric measures of IQ in subjects who were later diagnosed with schizophrenia, schizoaffective disorder, or schizophreniform disorder, 2) similar comparison data, and 3) sufficient data for calculation of an effect size. The analogue to the analysis of variance method was used to model between-study variance due to key study-design features.Results: Overall, schizophrenia samples demonstrated a reliable, medium-sized impairment in premorbid IQ. The heterogeneity of effect sizes was minimal and almost exclusively the result of one study. Methodological differences, such as diagnostic criteria, type of IQ measure, sample ascertainment, and age at premorbid testing, contributed minimally to the effect size variance. A cross-sectional analysis of all studies by age and a descriptive review of studies that used repeated measures of IQ in a single sample did not support the presence of a relative decline in IQ during the premorbid period in individuals with schizophrenia. However, all studies with pre- and post-onset testing within the same sample suggested that a significant decline in the IQ of individuals with schizophrenia, relative to comparison subjects, was associated with the onset of frank psychosis.Conclusions: Years before the onset of psychotic symptoms, individuals with schizophrenia, as a group, demonstrate mean IQ scores approximately one-half of a standard deviation below that of healthy comparison subjects.