Neuropsychological performance in first-episode adolescents with schizophrenia: a comparison with first-episode adults and adolescent control subjects.

BACKGROUND: The goal of this study was to compare the extent of cognitive deficits between adolescents and adults early in the course of schizophrenia. METHODS: A comprehensive neuropsychological battery was performed on 49 adolescents with childhood- or adolescent-onset schizophrenia, 139 adults with adult-onset schizophrenia, 32 healthy adolescent volunteers, and 240 healthy adult volunteers. Both patient groups were assessed early in the course of their illness and were matched to their respective control groups on age and parental education. RESULTS: The adolescent patients performed significantly worse than the adult patients on tasks of working memory, language, and motor function. The healthy adolescents also performed significantly worse than the healthy adults in working memory and language tasks but were significantly better than the adults in motor function. When accounting for developmental differences in the control group, only motor performance was worse in the adolescent patients compared with the adult patients. CONCLUSIONS: These findings, when coupled with published retrospective studies reporting greater cognitive deficits in earlier onset schizophrenia, implicate a cessation in development in specific cognitive domains following the onset of schizophrenia in adolescent patients.     

Striatal dysfunction in schizophrenia and unaffected relatives.

BACKGROUND: Schizophrenia has been frequently associated with impaired inhibitory control. Such control is known to involve the striatum. Here, we investigate whether impaired inhibitory control is associated with abnormal striatal activation in schizophrenia. First-degree relatives of patients were also tested to examine whether striatal abnormality is associated with schizophrenia, or with the risk for the illness. METHODS: Both functional MRI and behavioral data were acquired during a task designed to invoke inhibitory control in 21 patients, 15 unaffected siblings, and 36 matched controls. Subjects must refrain from responding to designated stop cues occurring within a series of motor cues. Subjects could anticipate the occurrence of stop cues as the likelihood of these cues increased in a linear fashion throughout the task. RESULTS: Control subjects showed striatal activation while responding to motor cues. This activation increased in a linear fashion when the likelihood of having to inhibit the response was increased. Both patients siblings did not show anticipation-related increase in either striatal activation. However, only patients showed behavioral impairments. CONCLUSIONS: Striatal abnormalities occur in schizophrenia patients and unaffected siblings. Thus striatal abnormalities may be related to an increased (genetic) risk to develop schizophrenia.     

Sex differences in striatal presynaptic dopamine synthesis capacity in healthy subjects.

BACKGROUND: There are sex differences in the clinical features of several neuropsychiatric illnesses associated with dopamine dysfunction. The effects of sex on brain dopaminergic function have been sparsely studied in human subjects using modern imaging techniques. We have previously reported that the apparent affinity of [(11)C]raclopride for striatal D(2) dopamine receptors in vivo is lower in women than in men, whereas D(2) receptor density is not different. This finding indirectly suggests that women have a higher synaptic concentration of dopamine in the striatum. We explored further the basis of this phenomenon in an independent study and hypothesized that striatal presynaptic dopamine synthesis capacity would also be elevated in women. METHODS: A total of 23 healthy men and 12 healthy women (age range 20-60 years) were studied using positron emission tomography and [(18)F]fluorodopa. RESULTS: Women had significantly higher striatal [(18)F]fluorodopa uptake (Ki values) than men. The difference was more marked in the caudate (+26%) than in the putamen (+12%). In addition, there was a negative correlation between striatal [(18)F]fluorodopa Ki values and age in men but not in women. CONCLUSIONS: The results further substantiate sex differences in striatal dopaminergic function in humans. This finding may be associated with sex differences in vulnerability and clinical course of neuropsychiatric disorders with dopaminergic dysregulation, e.g., schizophrenia, alcohol dependence, and Parkinson's disease.     

Maximum-uncertainty linear discrimination analysis of first-episode schizophrenia subjects

Recent techniques of image analysis brought the possibility to recognize subjects based on discriminative image features. We performed a magnetic resonance imaging (MRI)-based classification study to assess its usefulness for outcome prediction of first-episode schizophrenia patients (FES). We included 39 FES patients and 39 healthy controls (HC) and performed the maximum-uncertainty linear discrimination analysis (MLDA) of MRI brain intensity images. The classification accuracy index (CA) was correlated with the Positive and Negative Syndrome Scale (PANSS) and the Global Assessment of Functioning scale (GAF) at 1-year follow-up. The rate of correct classifications of patients with poor and good outcomes was analyzed using chi-square tests. MLDA classification was significantly better than classification by chance. Leave-one-out accuracy was 72%. CA correlated significantly with PANSS and GAF scores at the 1-year follow-up. Moreover, significantly more patients with poor outcome than those with good outcome were classified correctly. MLDA of brain MR intensity features is, therefore, able to correctly classify a significant number of FES patients, and the discriminative features are clinically relevant for clinical presentation 1 year after the first episode of schizophrenia. The accuracy of the current approach is, however, insufficient to be used in clinical practice immediately. Several methodological issues need to be addressed to increase the usefulness of this classification approach.     

精神分裂症首次发病患者及其健康同胞认知功能的比较研究

目的 比较精神分裂症首次发病患者与健康同胞及正常对照认知功能的差异,探讨精神分裂症在认知功能领域的内表型.方法 采用目前常用的范畴流畅测验(CFT)、数字符号编码测验(DSCT)、连线测验(TMT)、韦克斯勒记忆量表第3版(WMS-Ⅲ)空间广度测验(WMS-ⅢSST)、霍普金斯词汇学习测验-修订版(HVLT-R)、简易视觉空间记忆测验-修订版(BVMT-R)、定步调听觉连续加法测验(PASAT)和威斯康星卡片分类测验-64(WCST-64)对92例精神分裂症首次发病患者(患者组)、56例健康同胞(同胞组)和62名健康对照者(对照组)的认知功能进行检测.结果 (1)患者组所有神经心理测验成绩均差于对照组,差异有统计学意义(P＜0.01).(2)同胞组的CFT、DSCT、TMT、HVLT-R即刻记忆和延迟记忆、BVMT-R即刻记忆、PASAT、WCST-64持续错误数、持续反应数和完成分类数的测验成绩差于对照组,差异有统计学意义(P＜0.05).(3)患者组与同胞组的CFT、WCST-64中的持续错误数、持续反应数和完成分类数测验成绩分别为(18.40±12.12)分比( 18.86±5.19)分、(16.48±8.19)分比(14.80±5.86)分、(18.76±10.91)分比(16.86 ±7.73)分、(1.33±2.81)分比(1.63±1.36)分,2组比较差异无统计学意义(P＞0.05),其他神经心理测验成绩比较,患者组差于同胞组,差异有统计学意义(P＜0.05).结论 精神分裂症首次发病患者存在处理速度、工作记忆、言语记忆、空间记忆、注意警觉和执行功能广泛性的认知功能损害,精神分裂症健康同胞存在处理速度、言语记忆、视觉记忆、注意警觉、执行功能的认知缺陷;语义流畅性功能和执行功能可能是精神分裂症的潜在内表型.     

奥氮平与利培酮治疗首发精神分裂症对照研究

目的 比较奥氮平与利培酮治疗首发精神分裂症的疗效及不良反应。方法 随机将符合CCMD-2R精神分裂症的诊断标准70例患者进入奥氮平或利培酮组接受治疗,分别在治疗0、1、2、4、6、8周评定PANSS和TESS量表,在0、4、8周检查心脑电图和肝肾功能,在0、8周检查血催乳素和空腹血糖。结果 奥氮平与利培酮疗效相当,奥氮平能迅速减轻精神症状,其产生的不良反应少、严重程度轻,很少引起血催乳素变化;利培酮会显著提高血催乳素水平。结论 奥氮平对首发精神分裂症治疗安全有效。     

No difference in the prevalence of cavum septum pellucidum (CSP) between first-episode schizophrenia patients, offspring of schizophrenia patients and healthy controls

The reported prevalence of cavum septum pellucidum (CSP), is extremely variable (from 0.1% to 85%) depending upon the measurement method or imaging resolution. Higher prevalence of CSP has been found in schizophrenia. In this study, we examined the prevalence of CSP in a large number of first-episode schizophrenia patients, young relatives of schizophrenia patients and healthy controls. We manually measured CSP using 1.5 mm T1 MRI scans from ongoing studies at University of Pittsburgh in 89 first-episode patients with schizophrenia (age=23.8+/-7.4, M/F=61/28), 64 genetically at-risk individuals (offspring and siblings of schizophrenia patients, age 15.2+/-3.7, M/F=29/32) and 120 comparison subjects (n=120, age=22.1+/-7.9, M/F62/50). CSP was present in 64% of the first-episode patients (mean length 1.87+/-2.3 mm), 64.6% of the at-risk individuals (1.64+/-1.96 mm) and 64.2% of the normal controls (1.88+/-2.0 mm). There was no difference in the prevalence of CSP exceeding 4 mm. We also did not find any influence of the sex or age in the presence or size of CSP. Our data cast doubt on the significance of CSP as markers of neurodevelopmental pathology in schizophrenia.     

Basal ganglia volume in unmedicated patients with schizophrenia is associated with treatment response to antipsychotic medication

We investigated the relationship between basal ganglia volume and treatment response to the atypical antipsychotic medication risperidone in unmedicated patients with schizophrenia. Basal ganglia volumes included the bilateral caudate, putamen, and pallidum and were measured using the Freesurfer automated segmentation pipeline in 23 subjects. Also, baseline symptom severity, duration of illness, age, gender, time off medication, and exposure to previous antipsychotic were measured. Treatment response was significantly correlated with all three regions of the bilateral basal ganglia (caudate, putamen, and pallidum), baseline symptom severity, duration of illness, and age but not gender, time off antipsychotic medication, or exposure to previous antipsychotic medication. The caudate volume was the basal ganglia region that demonstrated the strongest correlation with treatment response and was significantly negatively correlated with patient age. Caudate volume was not significantly correlated with any other measure. We demonstrated a novel finding that the caudate volume explains a significant amount of the variance in treatment response over the course of 6 weeks of risperidone pharmacotherapy even when controlling for baseline symptom severity and duration of illness.     

Basal ganglia volumes in drug-naive first-episode schizophrenia patients before and after short-term treatment with either a typical or an atypical antipsychotic drug

The present study examined basal ganglia volumes in drug-naive first-episode schizophrenic patients before and after treatment with either a specific typical or atypical antipsychotic compound. Sixteen antipsychotic drug-naive and three minimally medicated first-episode schizophrenic patients and 19 matched controls participated. Patients were randomly assigned to treatment with either low doses of the typical antipsychotic drug, zuclopenthixol, or the atypical compound, risperidone. High-resolution magnetic resonance imaging (MRI) scans were obtained in patients before and after 12 weeks of exposure to medication and in controls at baseline. Caudate nucleus, nucleus accumbens, and putamen volumes were measured. Compared with controls, absolute volumes of interest (VOIs) were smaller in patients at baseline and increased after treatment. However, with controls for age, gender and whole brain or intracranial volume, the only significant difference between patients and controls was a Hemisphere x Group interaction for the caudate nucleus at baseline, with controls having larger left than right caudate nuclei and patients having marginally larger right than left caudate volumes. Within patients, the two medication groups did not differ significantly with respect to volume changes after 3 months of low dose treatment in any of the VOIs. Nevertheless, when medication groups were examined separately, a significant volume increase in the putamen was evidenced in the risperidone group. The altered asymmetry in caudate volume in patients suggests intrinsic basal ganglia pathology in schizophrenia, most likely of neurodevelopmental origin.     

Immediate effects of risperidone on cerebral activity in healthy subjects: a comparison with subjects with first-episode schizophrenia

OBJECTIVE: To test the hypothesis that administration of risperidone to healthy subjects produces reductions in metabolism in the frontal cortex similar to those produced by administration of risperidone to patients experiencing a first episode of schizophrenia. METHODS: Positron emission tomography was used to measure the changes in regional metabolism produced by a single 2-mg dose of risperidone and by placebo, administered under randomized, double-blind conditions, in 9 healthy subjects. Conjunction analysis was used to identify those cerebral sites where changes in metabolism in the healthy subjects coincided with similar changes in metabolism observed in patients with schizophrenia. RESULTS: Compared with placebo, risperidone produced reductions in metabolism in the left lateral frontal cortex and right medial frontal cortex in healthy subjects. Conjunction analysis revealed that these changes occurred at locations similar to the loci of change produced by risperidone in patients with schizophrenia. CONCLUSION: Because the reduction in metabolism in the medial frontal cortex produced by risperidone is associated with alleviation of positive symptoms in patients with schizophrenia, the observation of a reduction in metabolism at a similar site in healthy subjects supports the hypothesis that the antipsychotic effect of risperidone arises, at least in part, from a physiologic effect that occurs in both patients with schizophrenia and healthy subjects.     

Ventral striatopallidal parts of the basal ganglia in the rat: I. Neurochemical compartmentation as reflected by the distributions of neurotensin and substance P immunoreactivity

The distribution of neurotensin immunoreactivity in the basal ganglia of the adult rat was evaluated by studying alternate serial vibratome sections that were exposed to antiserum against neurotensin, substance P, or cholecystokinin. It was observed that a heterogeneous distribution of neurotensin-immunoreactive fibers and terminals contributes to the neurochemical compartmentation of the ventral pallidum and ventral striatum, and that significant numbers of neurotensin-immunoreactive neurons occupy striatal districts of the olfactory tubercle, nucleus accumbens, and ventromedial caudate-putamen. An intense band of pallidal neurotensin immunoreactivity characterizes the medial part of the ventral pallidum adjacent to the nucleus accumbens, whose medial boundary is conveniently defined in sections incubated with cholecystokinin antiserum. Electron microscopic studies showed that the pallidal plexus of neurotensin-immunoreactive elements consists primarily of boutons, which contact large dendrites in arrangements that in all respects appear to be of the classical striatopallidal variety. A gradual decrease in immunolabel was observed approaching the lateral parts of the ventral pallidum, which display sparse neurotensin immunoreactivity. The results thus indicate the existence of a significant neurotensinergic striatopallidal pathway confined primarily, if not exclusively, to the medial part of the ventral striatopallidal system. The contribution of neurotensin-immunoreactive fibers and terminals to the compartmentation of ventral striatum is expressed most vividly in their exclusion from clusters of tightly packed medium-sized neurons, many of which are intensely substance P immunoreactive. Such clusters appear identical with those previously described as rich in opiate receptors and poor in acetylcholinesterase activity. In the ventral striatal region where the nucleus accumbens and ventromedial caudate-putamen merge, neurotensin-immunoreactive neurons are organized in clusters. Further rostral in the nucleus accumbens, they are more evenly distributed. Few were found in the dorsolateral quadrant of the neostriatum.     

An MRI study of basal ganglia volumes in first-episode schizophrenia patients treated with risperidone

OBJECTIVE: The basal ganglia may contribute to extrapyramidal movement disorders, affective disturbances, and cognitive deficits in schizophrenia. Basal ganglia volumes are putatively affected by antipsychotic medications. The purpose of this study was to determine the long-term effects of risperidone treatment in a cohort of first-episode patients with schizophrenia. METHOD: The subjects were 30 patients with first-episode schizophrenia, 12 patients chronically treated with typical antipsychotics, and 23 healthy comparison subjects. They were scanned by magnetic resonance imaging at baseline. The first-episode patients received 1 year of continuous risperidone treatment, after which they and the comparison subjects were rescanned. Caudate, putamen, and globus pallidus volumes were determined from coronal images. RESULTS: The baseline caudate, putamen, and globus pallidus volumes were significantly larger in the chronically treated patients than in the untreated first-episode subjects and comparison subjects. These volumes did not differ between the first-episode patients and healthy comparison subjects. Basal ganglia volumes were unchanged after 1 year of exposure to risperidone in the first-episode subjects. Extrapyramidal movement disorders were present in the majority of chronically treated patients and more than one-third of the never-medicated first-episode patients at baseline. CONCLUSIONS: This group of first-episode patients did not exhibit abnormalities of basal ganglia volumes, nor were basal ganglia volumes affected by exposure to risperidone. Movement disorders were observed in both first-episode and chronically treated patients, suggesting effects of both illness and medications.     

Increased basal ganglia volumes in velo-cardio-facial syndrome (deletion 22q11.2).

BACKGROUND: This study evaluated differences in caudate volumes in subjects with velo-cardio-facial syndrome due to a 22q11.2 (22qDS) deletion. Because psychosis is observed in 30% of adult subjects with 22qDS, this neurogenetic disorder could represent a putative model for a genetically mediated subtype of schizophrenia.METHODS: Caudate volumes were measured on high-resolution magnetic resonance images in 30 children and adolescents with 22qDS and 30 gender- and age-matched normal comparison subjects.RESULTS: Caudate head volumes were increased in the 22qDS group independent of neuroleptic medications. Subjects with 22qDS also displayed an abnormal pattern of asymmetry in the anterior caudate, with left side greater than right.CONCLUSIONS: Alterations in the basal ganglia circuitry have been implicated in learning, cognitive, and behavioral problems in children and therefore could be involved in the expression of the neurobehavioral phenotype expressed by subjects with 22qDS. Abnormal caudate volume is a neurodevelopmental feature shared with schizophrenia, further establishing 22qDS as a potential neurodevelopmental model for this disorder.     

No effect of obstetric complications on basal ganglia volumes in schizophrenia

Background

Heterogeneous findings have been reported in studies of basal ganglia volumes in schizophrenia patients as compared to healthy controls. The basal ganglia contain dopamine receptors that are known to be involved in schizophrenia pathology and to be vulnerable to pre- and perinatal hypoxic insults. Altered volumes of other brain structures (e.g. hippocampus and lateral ventricles) have been reported in schizophrenia patients with a history of obstetric complications (OCs). This is the first study to explore if there is a relationship between OCs and basal ganglia volume in schizophrenia.

Methods

Thorough clinical investigation (including information on medication) of 54 schizophrenia patients and 54 healthy control subjects was undertaken. MR images were obtained on a 1.5 T scanner, and volumes of nucleus caudatus, globus pallidum, putamen, and nucleus accumbens were quantified automatically. Information on OCs was blindly collected from original birth records.

Results

Unadjusted estimates demonstrated a relationship between increasing number of OCs and larger volume of nucleus accumbens in schizophrenia patients and healthy controls. No statistically significant relationships were found between OCs and the basal ganglia volumes when controlled for intracranial volume, age, and multiple comparisons. There were no effects of typical versus atypical medication on the basal ganglia volumes. The patients with schizophrenia had larger globus pallidum volumes as compared to healthy controls, but there were no case–control differences for accumbens, putamen, or caudate volumes.

Conclusion

The present results do not support the hypothesis that OCs are related to alterations in basal ganglia volume in chronic schizophrenia.     

齐拉西酮对首发精神分裂症患者认知功能的影响

目的探讨齐拉西酮和氯丙嗪对首发精神分裂症患者认知功能的影响。方法将符合入组标准的首发精神分裂症86例随机分为齐拉西酮组与氯丙嗪组,分别进行8周的系统治疗,使用阳性与阴性症状量表(PANSS)评定疗效,治疗时出现的症状量表(TESS)评定不良反应,韦氏成人智力量表(WAISR)、韦氏记忆量表(WMS)和威斯康星卡片分类测验(WCST)评定治疗前后患者认知功能的改变。结果治疗后86例PAN-SS总分明显下降,两组之间差异无显著性(均P>0.05);齐拉西酮不良反应较氯丙嗪少,治疗前两组患者均有认知功能损害,治疗8周后,齐拉西酮组患者的认知功能有明显提高,而氯丙嗪组则无明显改善。结论齐拉西酮治疗精神分裂症疗效与氯丙嗪相当,且不良反应小,在改善认知功能方面优于氯丙嗪。     

Reduction of caudate nucleus volumes in neuroleptic-na?ve female subjects with schizotypal personality disorder.

BACKGROUND: The caudate nucleus might contribute to the psychopathological and cognitive deficits observed in schizotypal personality disorder (SPD), a schizophrenia spectrum disorder. Here we focused on female patients, because this group is underrepresented in studies of SPD and schizophrenia, and we might learn more about the caudate and clinical and cognitive impairments that are unique to female patients diagnosed with SPD. METHODS: Magnetic resonance imaging scans, obtained on a 1.5-T magnet with 1.5-mm contiguous slices, were used to measure the caudate in 32 neuroleptic-na?ve women with SPD and in 29 female normal comparison subjects. Subjects were group-matched for age, parental socioeconomic status, and intelligence quotient. RESULTS: We found significantly reduced left and right caudate relative volume (8.3%, 7.7%) in female SPD subjects compared with normal comparison subjects. In female SPD subjects, we found significant correlations between smaller total caudate relative volume and worse performance on the Wisconsin Card Sorting test (nonperseverative errors) and on the California Verbal Learning Test (verbal memory and learning), and significant correlations between smaller total caudate relative volume and both positive and negative symptoms on the Structured Interview for Schizotypy. CONCLUSIONS: These findings demonstrate that, for female SPD subjects, smaller caudate volume is associated with poorer cognitive performance and more schizotypal symptomatology.     

White matter lesion volumes and caudate volumes in late-life depression

BACKGROUND: Decreased caudate volumes and increased white matter lesions (WMLs) are associated both with aging and late-life depression, but the relationship between the two is unclear. We examined the association between WML and caudate volume, hypothesizing there would be a negative association, which would be stronger for WMLs located in anterior regions. We additionally hypothesized that this association would be stronger in depressed subjects. METHOD: This MRI study included 182 elderly depressed and 64 elderly control subjects. Our imaging analysis procedures divided the brain into anterior and posterior halves. WML volume in each half was calculated, as were left and right caudate volumes. A statistical model incorporating WML volumes, age, total brain volume, diagnosis, and gender was used to examine caudate volumes. RESULTS: WML volume was negatively associated with total and right caudate volume. This association was stronger for WMLs in the anterior half of the brain. Anterior WML volume was additionally negatively associated with right caudate volume in depressed subjects, but not in controls. CONCLUSIONS: Using unadjusted levels of significance, WML volume is negatively associated with right caudate volume in both older populations, but with left caudate volume only in depressed individuals. When statistical corrections for multiple comparisons are used, the finding is limited to a negative association between WML volume and right caudate volume, primarily in depressed subjects. This study demonstrates one mechanism by which WMLs may disrupt frontostriatal circuits.     

Striatal and forebrain nuclei volumes: contribution to motor function and working memory deficits in alcoholism.

BACKGROUND: Striatal structures are involved in dopaminergic alcohol reward mechanisms and aspects of motor control. Basal forebrain structures hold cholinergic mechanisms influencing memory formation, vulnerable to chronic alcoholism; however, alcoholism's effect on volumes of these structures has seldom been considered with in vivo measurement. METHODS: We measured bilateral volumes of caudate nucleus, putamen, nucleus accumbens, and medial septal/diagonal band (MS/DB) in 25 men with alcohol dependence and 51 age-matched control men. Six alcoholic subjects had been drinking recently, and 19 had been sober. RESULTS: Volumes of caudate and putamen were smaller in the alcoholics than in the control subjects, regardless of length of sobriety. Recent drinkers showed greater deficits in nucleus accumbens than sober alcoholics. Putamen volume was positively correlated with grip strength; MS/DB volume was positively correlated with verbal working memory independently of the negative association between age-standardized MS/DB and age in alcoholics. CONCLUSIONS: Caudate and putamen volume deficits occur and endure in chronic alcoholism. Nucleus accumbens might be especially sensitive to recent alcohol exposure. Striatal volumes should be considered in functional imaging studies of alcohol craving that target striatal brain regions. The age-alcohol interaction for MS/DB volumes is consistent with a cholinergic mechanism for the working memory impairment observed in the alcoholics.     

Assessment of empathy in first-episode psychosis and meta-analytic comparison with previous studies in schizophrenia

Empathy is a multidimensional construct that relies on affective and cognitive component processes. A few studies have reported impairments of both cognitive and affective empathy components in patients with schizophrenia. It is, however, not known whether these difficulties are already present at psychosis onset. The affective and cognitive components of empathy were thus assessed in 31 patients with first-episode psychosis (FEP) and 31 matched healthy controls using the Interpersonal Reactivity Index (IRI). Our results were then compared to previous studies of empathy in patients with more chronic schizophrenia via a meta-analysis. In addition, we also assessed the relationship between empathy ratings, Mentalizing performance and clinical symptoms. Contrary to what has been reported in people with more chronic schizophrenia, the IRI ratings did not significantly differ between FEP and controls in our study, though a trend was observed for the Personal distress scale. For the Perspective taking scale, our meta-analysis revealed a significantly lower effect size in this study with FEP patients relative to previous schizophrenia studies. In the FEP group, the IRI ratings were not related to positive, negative or general psychopathology symptoms, but a significant relationship emerged between the Liebowitz Social Anxiety Scale and Perspective taking (negative correlation). In addition, a significant positive correlation was observed between the Empathic concern subscale and our theory of mind task. This study supports the idea that the cognitive component of empathy is less affected in patients with first-episode psychosis relative to patients with more chronic schizophrenia, and the impairments reported in previous reports with more chronic populations should be interpreted in light of a possible deterioration of this cognitive skill. The findings also provide some insight into the relationship between empathy and clinical symptoms such as social anxiety.     

首发和慢性精神分裂症患者、正常对照者超氧化物歧化酶及脑源性神经营养因子水平的差异

背景有研究认为精神分裂症患者脑源性神经营养因子（brainderivedneurotrophiefactors,BDNF）含量降低,超氧化物歧化酶（superoxidedismutase,SOD）活性异常,但结果并不完全一致,可能与研究对象不同有关。目的探讨25例首发精神分裂症、慢性精神分裂症患者与正常人体内SOD活性、BDNF含量差异。评估病人组SOD、BDNF与临床特征的关系。方法收集符合美国精神障碍诊断与统计手册第4版诊断标准的首发精神分裂症住院患者78例,慢性精神分裂症住院患者67例,正常对照51名。以阳性和阴性综合征量表（PositiveandNegativeSyndromeScale,PANSS）评定精神症状,同时检测3组对象血SOD活性及BDNF含量。结果慢性精神分裂症患者组总超氧化物歧化酶（totalsuperoxidedismutase,T．SOD）与铜锌超氧化物歧化酶（CU—prozinc-superoxidedismutase,Cu-ZnSOD）活性最高,首发精神分裂症患者组次之,正常对照组最低。与之相反,慢性精神分裂症患者组血BDNF含量最低,首发精神分裂症患者组次之,正常对照组最高（所有差异均有统计学意义）。首发精神分裂症患者组的BDNF与Cu-ZnSOD呈负相关（r=一0．24,P=0．038）,但在正常对照组与慢性精神分裂症患者组无此负相关;3组的BDNF与T-SOD均不相关。在未服药的首发精神分裂症患者中,精神症状的严重程度与血清Cu—ZnSOD水平存在显著负相关,（主要是阳性症状）与BDNF水平存在显著正相关,但在服药的慢性患者中无上述相关。结论与首发精神分裂症患者相比,慢性精神分裂症患者的血清SOD活性增加,血BDNF含量下降。首发精神分裂症患者的SOD活性与血BDNF含量与疾病严重程度相关,但此关联随着疾病进展而逐渐弱化。