精神分裂症患者及其一级亲属认知功能和阴性症状相关性研究

目的:探讨精神分裂症患者及其一级亲属认知功能和阴性症状的相关性。方法:精神分裂症患者44例及其一级亲属78名完成修订版韦氏成人智力量表的词汇测验(VS)、多维记忆评估量表的数字广度(DS)、汉词广度(WS)和空间广度(SS)测验、威斯康星卡片分类测验(WCST)及持续注意测验(CPT),使用阳性和阴性症状量表(PANSS)的阴性症状分量表对受试者阴性症状进行评估。分析其相关性。结果:患者的VS、WS、SS、大部分WCST和CPT成绩与阴性症状总分相关(P0.05或P0.01);患者亲属的VS、DS、WS、SS、CPT的视觉漏报和视觉反应时间与阴性症状总分相关(P均0.01)。多元逐步回归分析显示,患者的VS、WCST完成分类和正确数、CPT听觉错误和视觉错误进入回归方程,联合预测阴性症状68.8%的变异,患者亲属的VS和CPT视觉漏报联合预测阴性症状63.9%的变异。结论:精神分裂症患者和一级亲属的认知功能与阴性症状有一定的相关性,但不完全重叠。     

强迫障碍患者一级亲属认知功能及神经系统软体征的对照研究

目的 研究强迫障碍患者一级亲属的认知功能及神经系统软体征。方法 选择2015 年 6 月—2017 年6 月在荆州市精神卫生中心门诊及住院治疗的70 例强迫障碍,将一级亲属分为高发家系 组及散发家系组,采用汉密尔顿焦虑量表（HAMA）来评价一级亲属的焦虑症状,采用耶鲁-布朗强迫量 表（Y-BOCS）来测试他们的强迫障碍状,采用威斯康星卡片分类测验（WCST）、Stroop 色词测验、持续操作 测验（CPT）及记忆量表来测试认知功能;采用剑桥神经科检查（CNI）软体征测试分量表测试神经系统软 体征。结果 高发家系组Y-BOCS 总分、HAMA总分较散发家系组评分高,差异有统计学意义（t分别为 4.85、2.61,P＜ 0.05）;高发家系组Stroop 色词测验、WCST、CPT、记忆量表项目评分低于散发家系组,差 异有统计学意义（P＜ 0.05）;高发家系组的NSS 总分及运动协调和脱抑制分量表评分高于散发家系组, 差异有统计学意义（t分别为2.15、3.03、3.14,P＜0.05）。结论 高发家系组一级亲属比散发家系组一级亲 属较多地出现焦虑、强迫障碍状,也更容易出现神经系统软体征及注意力、记忆力等方面的认知功能损害。     

精神分裂症一级亲属认知功能研究

目的:探讨精神分裂症一级亲属的认知功能。方法:100例精神分裂症患者的一级亲属(亲属组)与90名对照者(对照组)均采用威斯康星卡片分类测验(WCST)与持续操作测验(CPT)评估其认知功能。结果:亲属组WCST中总测验次数、持续错误数、随机错误数等均显著高于对照组(P<0.01);但CPT评分与对照组差异无显著性(P>0.05);亲属组WCST中有认知功能障碍的例数显著高于对照组(P<0.01),而在CPT中两组差异无显著性(P>0.05)。WCST中的持续错误数和CPT评分与患者的文化程度、性别、年龄之间无显著相关性(P>0.05)。结论:部分精神分裂症患者的一级亲属存在认知功能障碍,对严重者有必要进行干预。     

精神分裂症患者未患病一级亲属的认知功能研究

目的 探讨精神分裂症未患病的一级亲属认知功能的特点。方法 对110例精神分裂症患者未患病一级亲属（亲属组）及50例正常对照（对照组）进行认知功能测验,包括持续注意力测试（CPT）、威斯康星卡片分类测试（WCST）、修订版韦氏记忆量表（WMS-RC）的逻辑记忆和词语流畅性测试。结果 精神分裂症患者一级亲属在WMS-RC逻辑记忆中的即刻逻辑记忆、延迟逻辑记忆,词语流畅性测试中的词语总数、词语正确数,CPT中的视觉漏报、视觉平均反映时间1和2、听觉漏报数、听觉平均反应时间1和2的成绩均差于对照组（P〈0.05）。结论 精神分裂症未患病的一级亲属存在一定程度的认知功能损害,提示认知损害可能是精神分裂症的内表型指标之一。     

双相障碍患者一级亲属的认知功能研究

目的探讨双相障碍患者一级亲属的认知功能特点。方法选用10项神经心理测验对53例双相障碍患者未患病的一级亲属、97例正常对照个体进行认知功能的评定。结果亲属组的即刻逻辑记忆分为(9.11±2.95)分,明显差于对照组(12.06±3.21)分,差异具有统计学意义(P0.01),亲属组的延迟逻辑记忆分为(6.89±3.41)分,明显差于对照组(10.06±3.30)分,差异具有统计学意义(P0.01);亲属组的威斯康星卡片分类(WCST)测验分类数为(4.57±1.75)个,明显少于对照组(5.15±1.27)个,差异具有统计学意义(P0.05)。结论双相障碍患者一级亲属可能具有言语记忆和执行功能障碍,其受损的认知功能可能是双相障碍的遗传"内表型"指标。     

社区精神分裂症患者未患病一级亲属的认知功能研究

目的:探讨社区内的偏执型精神分裂症患者未患病一级亲属的认知功能特点。方法:采用威斯康辛卡片分类测验(WCST)、木块图测验、数字广度测验、电脑版Stroop颜色干扰测验与Oddball测验(新异刺激范式)对68名社区内精神分裂症患者的未患病一级亲属(亲属组)和58名正常对照者(对照组)进行综合分析能力、空间协调、工作记忆等执行功能评定及比较。结果:亲属组WCST中重复错误(P=0.003)、完成分类(P=0.004)、完成总数(P=0.029)、错误应答(P=0.018)、持续错误(P=0.037)、数字广度倒背(t=-2.667,P=0.009)成绩显著差于对照组;Stroop测验中亲属组反应时显著长于对照组,正确率显著低于对照组(P均0.000);在Oddball测试中亲属组仅反应时显著长于对照组(P0.000),正确率两组间差异无统计学意义。结论:精神分裂症患者一级亲属存在综合分析能力和工作记忆缺陷,其有可能是精神分裂症的内表型。     

儿童少年期精神分裂症患者及其一级亲属认知功能的对照研究

目的:探讨儿童少年期精神分裂症患者及其一级亲属的认知功能状况. 方法:对40例儿童少年期精神分裂症患者(患者组)、80名父母(患者父母组)及22名同胞(患者同胞组)采用注意力测验、WMS-R-逻辑记忆、数字广度、连线测验A和B、词汇流畅性测验、Stroop色词测验及威斯康星卡片分类测验(WCST)评定其认知功能,并与59名健康儿童(健康儿童对照组)及其父母(健康儿童父母组)80名进行比较. 结果:患者组除词汇流畅性测验以外,其他测验成绩差于健康儿童对照组;患者同胞组除数字顺背、词汇流畅性测验、连线测验-A、WCST正确应答数、WCST完成第1个分类应答数以外,其他测验成绩差于健康儿童对照组(P均＜0.001);患者父母组除数字顺背、词汇流畅性测验、连线测验-A以外,其他测验成绩差于健康儿童父母组(P＜0.01或P＜0.001).儿童精神分裂症患者与其父母在注意力测验、WMS-R-逻辑记忆、数字倒背、彩色文字阅读和彩色文字颜色阅读、WCST完成分数上呈正相关(r =0.350～0.615,P＜0.05或P＜0.001). 结论:儿童少年期精神分裂症患者及其一级亲属均存在广泛的认知功能缺陷,但患者的认知功能障碍更为严重.     

精神分裂症患者SK3基因内CTG重复扩展突变与临床症状的相关研究

目的 探讨精神分裂症患者的弱传导钙激活钾通道蛋白(SK3)基因内CTG重复数目及其与临床症状的关系。方法 采用聚合酶链反应(PCR)扩增技术,对30例高发家系的精神分裂症患者,30例散发精神分裂症患者以及5个高发家系的10例同病者和17名未患病的一级亲属进行SK3基因内CTG重复数目检测,同时对70例精神分裂症患者进行下列评定:阳性症状评定量表(SAPS)、阴性症状评定量表(SANS)和治疗副反应量表(TESS);韦氏智力量表(WAIS-R)、韦氏记忆量表(WMS)、威斯康星卡片分类测验(WCST)、连线测验A(Trial-A)及语言流利性测验(LFT)。结果 高发和散发精神分裂症患者的CTG重复数目明显高于正常对照者,差异有非常显著性(X±SD分别为8.8±1.2,7.9±0.7,6.2±0.6,P<0.01),尤以高发家系最为明显。CTG重复数目与阴性症状呈显著正相关(r=0.769,P=0.000),而与认知功能呈显著负相关(r=-0.350-0.690,P_均<0.05)。结论 精神分裂症SK3基因内CTG重复多态性变化可能是该病的一个生物学致病因素。     

精神分裂症和抑郁症患者一级亲属注意功能研究

目的:探索精神分裂症、抑郁症患者一级亲属的注意功能特征。方法:对41例精神分裂症先证者的62例一级亲属、34例抑郁症先证者的55例一级亲属进行持续性操作测验(CPT)检测,并以54例精神正常者作为对照。结果:在反应时间分测验中,精神分裂症亲属组和抑郁症亲属组所有的CPT指标均高于对照组(P<0.05或P<0.01);大多数指标低于相应的患者组(P<0.05或P<0.01)。在X分测验中,针对靶刺激,上述两个亲属组的大多数CPT指标高于对照组(P<0.05或P<0.01);部分指标低于相应的患者组(P<0.05或P<0.01)。精神分裂症或抑郁症患者的部分CPT指标分别与其一级亲属呈显著性正相关(P<0.05或P<0.001)。在针对靶刺激的8项指标中,抑郁症亲属组有4项指标低于精神分裂症亲属组(P<0.05或P<0.01)。结论:精神分裂症和抑郁症患者的一级亲属都呈现出注意功能缺陷,但他们的CPT表现形式有所不同。从而提示,注意缺陷有可能是精神障碍的一项遗传易感因子,但他们并非精神分裂症所特有。     

精神分裂症和双相障碍的健康一级亲属认知功能的对照研究

目的探讨精神分裂症和双相障碍患者的健康一级亲属的认知功能缺陷的异同点。方法纳入精神分裂症和双相障碍两类患者的健康一级亲属各50名、正常对照组50名。采用数字符号、连线测验(trailmarking test,TMT)A和B、数字广度、图形视觉再生、言语流畅性、威斯康星卡片、汉诺塔(Hanoi tower,HOT)评估被试者的注意、记忆和执行功能,比较3组间的差异。结果 3组间数字符号总分、TMT-A时间、数字广度(总分及倒背)、视觉图形再生总分、言语流畅性总分、WSCT持续错误数、HOT总分及完成任务数等成绩的差异均有统计学意义(P<0.05)。两两比较显示,精神分裂症亲属组上述所有指标的成绩均差于正常对照组(P<0.05),而双相障碍亲属组仅数字符号、TMT-A时间、数字广度总分及倒背、言语流畅性总分均差于正常对照组(P<0.05),精神分裂症亲属组的图形视觉再生、HOT总分及完成任务数均比双相障碍亲属组差(均P<0.05)。结论两类患者的健康一级亲属均存在注意、记忆和执行功能等认知缺陷,精神分裂症亲属的认知缺陷更显著,提示认知缺陷既是两类精神疾病共同的遗传易感因素,但又在两类疾病的家系中的遗传负荷有所不同。     

Left hippocampal volume as a vulnerability indicator for schizophrenia: a magnetic resonance imaging morphometric study of nonpsychotic first-degree relatives

BACKGROUND: Clues to the causes of schizophrenia can be derived from studying first-degree relatives because they are genetically related to an ill family member. Abnormalities observed in nonpsychotic relatives are indicators of possible genetic vulnerability to illness, independent of psychosis. We tested 4 hypotheses: (1) that hippocampal volume is smaller in nonpsychotic relatives than in controls, particularly in the left hemisphere; (2) that hippocampi will be smaller in multiplex relatives as compared with simplex relatives, and both will be smaller than in controls; (3) that hippocampal volumes and verbal declarative memory function will be positively correlated; and (4) that hippocampi will be smaller in patients with schizophrenia than in their nonpsychotic relatives or in controls. METHODS: Subjects were 45 nonpsychotic adult first-degree relatives from families with either 2 people ("multiplex," n = 17) or 1 person ("simplex," n = 28) diagnosed with schizophrenia, 18 schizophrenic relatives, and 48 normal controls. Sixty contiguous 3-mm coronal, T1-weighted 3-dimensional magnetic resonance images of the brain were acquired on a 1.5-T magnet. Volumes of the total cerebrum and the hippocampus were measured. RESULTS: Compared with controls, relatives, particularly from multiplex families, had significantly smaller left hippocampi. Verbal memory and left hippocampal volumes were significantly and positively correlated. Within families, hippocampal volumes did not differ between schizophrenic patients and their nonpsychotic relatives. CONCLUSIONS: Results support the hypothesis that the vulnerability to schizophrenia includes smaller left hippocampi and verbal memory deficits. Findings suggest that smaller left hippocampi and verbal memory deficits are an expression of early neurodevelopmental compromise, reflecting the degree of genetic liability to schizophrenia.     

Neuropsychologic functioning among the nonpsychotic relatives of schizophrenic patients: the effect of genetic loading.

BACKGROUND: We previously reported that the nonpsychotic relatives of schizophrenic patients exhibited disturbances in executive functioning, verbal and visual memory, auditory attention, mental control, and verbal ability. In a 4-year follow-up, we showed that the discriminating power of most of these tests was stable over time. METHODS: In this report we compare 41 nonpsychotic persons who have only one schizophrenic first-degree relative (simplex families) with 36 nonpsychotic persons who have two schizophrenic first-degree relatives (multiplex families). Our goal was to test a hypothesis that neuropsychologic deficits would be worse among the latter. RESULTS: Relatives from multiplex families differed significantly from controls on estimated intelligence, immediate and delayed logical memories, and immediate visual reproductions. In contrast, in comparisons with controls, relatives from simplex families only differed on immediate logical memories. Comparisons between relatives from multiplex and simplex families showed that the former group had significantly worse scores for estimated intelligence, immediate and delayed logical memories, and immediate visual reproductions. We also found group x gender interactions: the worse performance of the multiplex group was seen for females. CONCLUSIONS: These results are consistent with the idea that neuropsychologic deficits in relatives of schizophrenic patients reflect their degree of genetic predisposition to schizophrenia. They also suggest hypotheses about gender differences in the familial transmission of the disorder.     

Impaired flush response to niacin skin patch among schizophrenia patients and their nonpsychotic relatives: the effect of genetic loading

We previously reported familial aggregation in flush response to niacin skin patch among schizophrenia patients and their nonpsychotic relatives. However, little is known about whether this abnormal skin response is associated with genetic loading for schizophrenia. This study compared the niacin flush response in subjects from families with only one member affected with schizophrenia (simplex families) with those from families having a sib-pair with schizophrenia (multiplex families). Subjects were patients with schizophrenia and their nonpsychotic first-degree relatives from simplex families (176 probands, 260 parents, and 80 siblings) and multiplex families (311 probands, 180 parents, and 52 siblings) as well as 94 healthy controls. Niacin patches of 3 concentrations (0.001M, 0.01M, and 0.1M) were applied to forearm skin, and the flush response was rated at 5, 10, and 15 minutes, respectively, with a 4-point scale. More attenuated flush response to topical niacin was shown in schizophrenia probands and their relatives from multiplex families than in their counterparts from simplex families, and the differentiation was better revealed using 0.1M concentration of niacin than 0.01M or 0.001M. For the highest concentration of 0.1M and the longest time lag of 15 minutes, a subgroup of probands (23%), parents (27%), and siblings (19%) still exhibited nonflush response. Flush response to niacin skin patch is more impaired in schizophrenia patients and their relatives from families with higher genetic loading for schizophrenia, and this finding has implications for future genetic dissection of schizophrenia.     

More severe sustained attention deficits in nonpsychotic siblings of multiplex schizophrenia families than in those of simplex ones

Sustained attention deficits measured by the Continuous Performance Test (CPT) have been proposed as an endophenotype of schizophrenia. However, little is known about whether sustained attention deficits in first-degree relatives of schizophrenic patients are associated with familial loading for schizophrenia. We examined 107 parents and 84 siblings of simplex schizophrenia families as well as 72 parents and 56 siblings of multiplex schizophrenia families, all nonpsychotic, using the Diagnostic Interview for Genetic Studies and two sessions of the CPT (undegraded and degraded). The effect of perceptual load was assessed using the residual of the regression of the degraded score on the undegraded one. Statistical models that can adjust for familial correlations were used to compare the CPT performance of relatives between the two types of families. Siblings from multiplex families exhibited worse performance on the degraded CPT and less proficiency in processing the perceptual load than those from simplex families. No such difference was observed for the parents on either CPT version. We concluded that sustained attention along with perceptual load processing is more impaired in the siblings of schizophrenic patients with high familial loading and that this finding might be useful for future genetic dissection of schizophrenia.     

Hypothalamic abnormalities in schizophrenia: sex effects and genetic vulnerability.

BACKGROUND: This is a unique hypothalamic magnetic resonance imaging (MRI) study in schizophrenia, an important region in the limbic system. We hypothesized abnormal volumetric increases, with greater severity in multiplex families (more than one ill member) compared with simplex families (one ill). We tested the hypothesis that normal hypothalamic sexual dimorphism is disrupted in schizophrenia. METHODS: Eighty-eight DSM-III-R schizophrenia cases (40 simplex and 48 multiplex), 43 first-degree nonpsychotic relatives, and 48 normal comparisons systematically were compared. A 1.5-Tesla General Electric scanner was used to acquire structural MRI scans, and contiguous 3.1-mm slices were used to segment anterior and posterior hypothalamus. General linear model for correlated data and generalized estimating equations were used to compare cases, relatives, and controls on right and left hypothalamus, controlled for age, sex, and total cerebral volume. Spearman's correlations of hypothalamic volumes with anxiety were calculated to begin to examine arousal correlates with structural abnormalities. RESULTS: Findings demonstrated significantly increased hypothalamic volume in cases and nonpsychotic relatives, particularly in regions of paraventricular and mammillary body nuclei, respectively. This increase was linear from simplex to multiplex cases, was positively correlated with anxiety, and had a greater propensity in women. CONCLUSIONS: Findings suggest important implications for understanding genetic vulnerability of schizophrenia and the high rate of endocrine abnormalities.     

Schizophrenia spectrum disorders and eye tracking dysfunction in singleton and multiplex schizophrenia families

One line of research which is helping to unravel the genetic susceptibility to schizophrenia (SZ) is the analysis of eye tracking dysfunction (ETD), a quantifiable phenotypic marker. To investigate if such a biological marker is also present in singleton schizophrenia families, we examined eye tracking in members of singleton families (N=53) and compared it to members of multiplex (N=76) and nonpsychiatric families (N=71) using high resolution infrared oculography. The prevalence of ETD defined by gain values (eye/target velocity) and saccadic frequencies during smooth pursuit at 15 degrees /s did not differ between multiplex and singleton families in either the schizophrenic index patients or their relatives, but was significantly different from nonpsychotic families. ETD rate was higher in those relatives with compared to those without a diagnosis of a schizophrenia spectrum disorder. In relatives with a spectrum disorder, ETD appeared to be associated with traits for "sensitivity" and "suspiciousness". In the group of relatives from singleton families without a schizophrenia spectrum disorder, we still found a higher prevalence of ETD than in nonpsychotic families. Our results suggest that eye tracking dysfunction is a very sensitive biological marker for the vulnerability to schizophrenia, even in those cases where no psychopathological symptoms or signs are obvious. ETD in schizophrenia is suggested to serve as a neurophysiological type model, indicating a perception deficit.     

A review and new report of medial temporal lobe dysfunction as a vulnerability indicator for schizophrenia: a magnetic resonance imaging morphometric family study of the parahippocampal gyrus

A central question in schizophrenia research is which brain abnormalities are independent of psychosis and which evolve before and after psychosis begins. This question can be addressed by longitudinal neuroimaging studies beginning in the prodrome, but at present there is only one published study. We reviewed the literature on structural brain imaging in persons with chronic and first episode schizophrenia, nonpsychotic persons at genetic high risk, and persons thought to be at risk for imminent psychosis ("prodromal" persons). Medial temporal lobe (MTL), especially hippocampal, volume alterations are among the most robust brain vulnerabilities for schizophrenia. Because verbal declarative memory (VDM) deficits are prominent and the parahippocampal gyrus (PHG) is considered to be centrally involved with the hippocampus in VDM processing, we analyzed PHG data from a family study of schizophrenia. Patients with schizophrenia and nonpsychotic relatives from "multiplex" families (families with multiple persons with schizophrenia) had significantly smaller right parahippocampal anterior (PHa) volumes than controls. Marginally significant findings were observed for the left PHa. Unexpectedly, relatives from "simplex" families (families with only one person with schizophrenia) had significantly larger PH posterior volumes than controls and did not differ from controls on PHa. Results provide some support for the hypothesis that the vulnerability to schizophrenia includes abnormal volumes of the PHG. These data provide additional support for the hypothesis that some MTL abnormalities in schizophrenia are independent of psychosis, at least in families with presumably high genetic loading. Implications of genetic risk studies for prodromal research are discussed.     

Familial resemblance for executive functions in families of schizophrenic and bipolar patients

Executive dysfunctions are considered to be putative markers of familial/genetic vulnerability to both schizophrenia and bipolar disorder. However, familial resemblance must be demonstrated before executive functions are used as a potential endophenotype. The aim of this study was to investigate familial resemblance for executive functions in families of schizophrenic and bipolar subjects. We assessed executive functions by means of two tests - the Wisconsin Card Sorting Test (WCST) and the Trail Making Test (TMT) - in 351 subjects from five populations: schizophrenic patients, bipolar patients, a group of relatives for each patient group and controls. For both tests, cognitive assessment results were consistent with previous studies: schizophrenic patients showed the greatest impairment, followed by bipolar patients and then the two groups of relatives. In families of bipolar patients we observed familial resemblance for the WCST and part A and part B of the TMT. However, by contrast with the classical point of view, considering executive measures to be markers of genetic vulnerability to schizophrenia, we did not demonstrate familial resemblance for either of the two executive tests in families of schizophrenic patients. Thus, executive measures, as assessed by the WCST or the TMT, should not be used as endophenotypes in genetic studies of schizophrenia unless confounders are identified and their effects eliminated.     

Relationship between positive and negative symptoms of schizophrenia and schizotypal symptoms in nonpsychotic relatives.

BACKGROUND: Continuous rather than categorical measures of psychopathology may provide greater statistical power to detect susceptibility loci for schizophrenia. However, it has not been established that the dimensions of schizophrenic symptomatology and personality traits in nonpsychotic individuals share etiological factors. We therefore sought to clarify the relationship between positive and negative symptoms of schizophrenic probands and dimensions of schizotypy in their first-degree relatives. METHODS: In the Roscommon Family Study, we examined the ability of positive and negative symptoms in probands to predict 7 factors of schizotypy in nonpsychotic relatives using regression analysis. These consisted of positive, negative, and avoidant symptoms; odd speech; suspicious behavior; social dysfunction; and symptoms of borderline personality disorder. We examined 3 proband groups: schizophrenia (n = 127); schizophrenia, simple schizophrenia, and schizoaffective disorder (n = 178); and all nonaffective psychoses (n = 216), and their nonpsychotic relatives (n = 309, 477, and 584, respectively). RESULTS: Positive symptoms in all nonaffective psychoses probands predicted positive schizotypy (beta = 0.1972, P =.0004), social dysfunction (beta = 0.0719, P =.0489), and borderline personality disorder symptoms (beta = 0.1327, P =.0084) in relatives, while negative symptoms predicted negative schizotypy (beta = 0.2069, P =.0002), odd speech (beta = 0.2592, P =.0001), suspicious behavior (beta = 0.2749, P =.0001), and social dysfunction (beta =.2398, P =.0002). Proband negative symptoms and borderline personality disorder symptoms in relatives in the schizophrenia, simple schizophrenia, and schizoaffective disorder group were inversely related (beta = -0.1185, P =.05). CONCLUSIONS: Positive and negative symptoms in schizophrenia predict corresponding schizotypal symptoms in relatives. This provides evidence that these schizophrenic symptom factors (1) are etiologically distinct from each other and (2) occur on an etiological continuum with their personality-based counterparts.     

The Maudsley family study I: Structural brain changes on magnetic resonance imaging in familial schizophrenia

1. 1. The authors investigated the prevalence of qualitatively rated structural brain abnormalities in schizophrenic probands and their first-degree relatives from families multiply affected with schizophrenia.

2. 2. Magnetic resonance imaging was used to evaluate brain morphology in 33 schizophrenic probands, 54 of their non-schizophrenic first-degree relatives (including 11 presumed obligate carriers) and 37 unrelated control subjects. Structural images were examined by a neuroradiologist who was blind to diagnostic and family status.

3. 3. 52% of the schizophrenic subjects were rated as showing abnormalities compared with 27% of presumed obligate carriers, 16% of their non-schizophrenic relatives and 11% of unrelated controls.

4. 4. Brain abnormalities were more frequent in schizophrenic subjects from multiplex families than in their first-degree relatives and controls. Abnormalities were also found in unaffected relatives particularly those who appear to be transmitting the disorder.