Personality traits in schizophrenia: comparison with a community sample

The objective of this study was to compare personality trait profiles in patients with schizophrenia and healthy controls. Male outpatients with schizophrenia (N = 24) and a male nonpsychiatric community sample (N = 46) completed the NEO-FFI personality questionnaire. Multivariate analyses were used to compare mean scale scores and scale profiles for each group. The overall personality profile of clinically stable patients with schizophrenia differed significantly from that of a community sample. On individual scales, patients scored significantly higher on neuroticism and significantly lower on conscientiousness. These results confirm and extend those of previous studies that used normative data for comparison and a much longer version of the same personality questionnaire. Prospective studies of populations at risk are needed to determine whether group differences reflect a premorbid diathesis for schizophrenia or a secondary effect of serious mental illness.     

No association between the PCM1 gene and schizophrenia: a multi-center case-control study and a meta-analysis

Alterations in centrosomal function have been suggested in the pathology of schizophrenia. The molecule pericentriolar material 1 (PCM1) is involved in maintaining centrosome integrity and in the regulation of the microtubule cytoskeleton. PCM1 forms a complex at the centrosome with the disrupted-in-schizophrenia 1 (DISC1) protein, which is a major susceptibility factor for schizophrenia. The association between genetic variants in the PCM1 gene and schizophrenia has been reported by several case-control studies, linkage studies and a meta-analysis. The aims of this study are to replicate the association between four single-nucleotide polymorphisms (SNPs) in the PCM1 gene and schizophrenia in a Japanese population (1496 cases and 1845 controls) and to perform a meta-analysis of the combined sample groups (3289 cases and 3567 controls). We failed to find a significant association between SNPs or haplotypes of the PCM1 gene and schizophrenia in the Japanese population (P>0.28). The meta-analysis did not reveal an association between the four examined SNPs and schizophrenia. Our data did not support genetic variants in the PCM1 gene as a susceptibility locus for schizophrenia.     

Ear disease and schizophrenia: a case-control study

The rates of middle ear disease in 70 patients with schizophrenia from a defined catchment population were compared with the rates in 359 nonpsychiatric controls who were matched for age, sex and general practice. A relative risk (odds ratio) of middle ear disease in schizophrenia of 1.92 was found. This was raised to 2.29 when ear disease occurring after the onset of schizophrenia was excluded. Excluding aetiological factors such as brain damage or family history raised the odds ratio further to 2.50 and 2.71 respectively. The implications of these results are discussed, and it is suggested that middle ear disease may be an aetiological factor in some cases of schizophrenia.     

School achievements and schizophrenia: a case-control study

OBJECTIVE: To compare school performance during middle childhood and adolescence among subjects later diagnosed with schizophrenia and their peers. METHOD: School records were ascertained from archives in 76 acutely symptomatic schizophrenic patients and 146 controls matched for gender and graded by the same teachers. RESULTS: At age 9, no differences in yearly graded school subjects were found. At 12, cases had higher marks in drawing/art and a tendency to excel in language and religion. At 15, the proficient performance in drawing/art remained, but cases performed worse than controls in gymnastics. The cases reported high frequency of school adaptation problems. Severity of psychotic symptoms at admission was associated with lower and declining marks. CONCLUSION: Schizophrenic patients seem to perform as well as their classmates in most subjects taught in compulsory basic school. Findings indicating specific talents in artistic ability and impairments in motor development need to be further investigated.     

Personality traits in schizophrenia and related personality disorders

We investigated whether schizophrenia spectrum disorders share common personality characteristics or traits. Participants with a diagnosis of schizophrenia or schizoaffective disorder (SZ) or with a schizophrenia spectrum personality disorder (schizophrenia spectrum PD: schizoid, paranoid, and schizotypal personality disorder) were compared with non-psychiatric control subjects on the five-factor model of personality and the psychosis-proneness scales. On the five-factor personality scales, SZ subjects showed higher levels of neuroticism, and lower levels of openness, agreeableness, extraversion, and conscientiousness than control subjects. Higher scores on openness and lower scores on neuroticism distinguished schizophrenia spectrum PD from SZ. On the psychosis-proneness scales, both PD and SZ participants scored high relative to non-psychiatric control participants on magical ideation and perceptual aberration, while PD participants scored intermediate between non-psychiatric control participants and SZ on social anhedonia. Discriminant analysis indicated that schizophrenia spectrum patients could be distinguished from PDs by more severe social withdrawal and maladjustment, while subjects with PDs could be best distinguished from control subjects on the basis of odd or novel ideation and decreased conscientiousness.     

Middle-ear disease and schizophrenia: case-control study

BACKGROUND: One hundred years ago psychiatrists thought that ear disease could cause insanity by irritation of the brain. Current understanding of the role of the temporal lobes in schizophrenia and their proximity to the middle ear supports this hypothesis. AIMS: To establish the rate of middle-ear disease pre-dating the onset of schizophrenia. METHOD: Eighty-four patients with schizophrenia were each matched to four non-psychiatric controls by age, gender and season of birth. History of ear disease was obtained from general practice records. Additional information on symptoms was collected for participants in the case group, who also had audiometry. RESULTS: The odds ratio of recorded middle-ear disease pre-dating schizophrenia was 3.68 (95% CI 1.86-7.28). This excess was particularly marked on the left (OR=4.15, 95% CI 2.08-8.29). Auditory hallucinations were associated with middle-ear disease but not with hearing loss. CONCLUSIONS: There is an association between middle-ear disease and schizophrenia which may have aetiological significance.     

Sex differences in the risk of schizophrenia: evidence from meta-analysis

BACKGROUND: Sex differences in the risk of a particular disorder can yield important clues regarding its pathogenesis. The evidence for a sex difference in the risk of schizophrenia is inconclusive. The purpose of this study was to integrate results from the published literature and to provide a quantitative index of the male-female ratio for the incidence of schizophrenia. METHODS: The MEDLINE and PsychLIT databases were searched for English-language publications on "incidence and schizophrenia" that appeared during the period between January 1980 and September 2001. Population-based incidence studies using standard clinical diagnostic criteria were included if they reported sex-specific incidence rates. Sex-specific incidence figures were extracted directly from each study. Categorical analyses were conducted on a subset of studies that met specific methodological criteria (to minimize criterion bias, hospital bias, and age bias). Study categorization and data extraction were performed independently by 2 of us (A. A. and J.-P.S.). RESULTS: Log risk ratio meta-analysis was conducted using a random-effects model. The incidence risk ratios for men to develop schizophrenia relative to women were 1.42 (95% confidence interval [CI], 1.30-1.56) when all studies were included in the analysis (49 effect sizes), 1.31 (95% CI, 1.13-1.51) when studies that minimized selection biases were analyzed separately (23 effect sizes), and 1.39 (95% CI, 1.15-1.68) when only high-quality studies were included (11 effect sizes). The sex difference was significantly smaller in studies with sample years before 1980 than those with sample years after 1980. No significant sex differences were reported in studies from developing countries. A final analysis, limited to studies with an age cutoff of 64 years or older (16 effect sizes), yielded a mean risk ratio of 1.32 (95% CI, 1.13-1.55). CONCLUSION: This meta-analysis provides evidence for a sex difference in the risk of developing schizophrenia, as reported in the published literature from the last 2 decades.     

Parental age and risk of schizophrenia: a case-control study

BACKGROUND: Advanced paternal age has been suggested as a possible risk factor for schizophrenia. It is not known whether this is explained by known risk factors for schizophrenia, including sibship characteristics, death of a parent before first hospital admission, season and place of birth, and family history of psychiatric illness, or by socioeconomic factors. We investigated the risk of schizophrenia associated with parental age, adjusting for known risk factors for schizophrenia, including family psychiatric history, and controlling for socioeconomic and demographic factors. METHODS: We performed a national population, nested, case-control study based on Danish longitudinal register data. The sample included 7704 patients with an ICD-8 or ICD-10 diagnosis of schizophrenia admitted to a psychiatric facility between 1981 and 1998 in Denmark, and 192 590 individually time-, age-, and sex-matched population controls, their parents, and siblings. The risk of schizophrenia associated with increasing parental age was investigated using conditional logistic regression and controlling for family socioeconomic and demographic factors and family psychiatric history. RESULTS: Advanced paternal and maternal age was associated with increased risk of schizophrenia in univariate analyses. Controlling for socioeconomic factors and family psychiatric history, increased risk of schizophrenia was identified in those with a paternal age of 50 years or older. Sex-specific analyses revealed that the risk of schizophrenia was increased for males with fathers 55 years or older (incidence rate ratio [IRR], 2.10; 95% confidence interval [CI], 1.35-3.28); for females, the risk associated with paternal age was substantial for fathers aged 50 to 54 years (IRR, 2.22; 95% CI, 1.44-3.44) and 55 years or older (IRR, 3.53; 95% CI, 1.82-6.83). CONCLUSION: Increased risk of schizophrenia was associated with advanced paternal age, particularly in females, lending support to the theory that de novo mutations, possibly X-linked, associated with increased parental age might be responsible for some cases of schizophrenia.     

Tau gene and Parkinson's disease: a case-control study and meta-analysis

OBJECTIVE: To investigate whether the tau H1 haplotype is a genetic risk factor in Parkinson's disease and to report a meta-analysis on all previously published data METHODS: and results: In a sample of 580 patients with Parkinson's disease and 513 controls there was an increased risk of Parkinson's disease for both the tau H1 haplotype (p相似文献   

Personality and psychopathology in schizophrenia: the association between personality traits and symptoms

Research has indicated that stable individual differences in personality exist among persons with schizophrenia, and that they likely predate the onset of illness. Little is known, however, about whether individual differences in personality are related to levels of psychopathology. This study tested the hypotheses that levels of Extroversion, Neuroticism, and Psychoticism are associated with symptomatology. Accordingly, measures of these dimensions of personality and of symptomatology were obtained simultaneously for 113 male subjects with schizophrenia or schizoaffective disorder. Next, subjects were characterized as having high or low levels on each personality dimension and their scores on the five components of the Positive Negative Syndrome Scale were compared using multivariate and univariate procedures. Results indicate that extroverted subjects had lower levels of Positive, Negative, and Emotional Discomfort symptoms, and higher levels of Excitement symptoms than introverted subjects. Subjects with higher levels of Neuroticism had higher levels of Positive and Emotional Discomfort symptoms than subjects with lower levels of Neuroticism. No differences in symptoms were found among subjects with higher versus lower levels of Psychoticism. Results suggest individual differences in personality are associated with psychopathology in schizophrenia and may help further explain the heterogeneity widely observed in this disorder.     

精神分裂症患者一级亲属人格特征的研究

目的 探讨精神分裂症患者一级亲属的人格特征.方法 采用分裂型人格问卷(SPQ)及三维人格问卷(TPQ)评定181例精神分裂症患者一级亲属(高危组)、321名正常对照个体(对照组)的人格特征.结果 高危组sPQ阴性分裂型人格维度评分[(9.80±7.05)分]高于对照组[(8.42±5.87)分],差异有统计学意义(P＜0.05).高危组在TPQ寻求新奇维度评分[(15.60±5.62)分]、奖赏依赖维度评分[(17.41 ±1.13)分]与对照组[(14.20±2.83)分,(18.22±3.26)分]的差异均有统计学意义(P均＜0.01).高危组的阴性分裂型人格维度分数与寻求新奇维度、奖赏依赖维度分数显著相关(r=0.17和-0.23).结论 精神分裂症患者一级亲属具有阴性分裂型维度、寻求新奇维度、奖赏依赖维度的人格特征.     

Association between schizophrenia and genetic variation in DCC: a case-control study

Schizophrenia is a highly heritable neurodevelopmental disorder associated with alterations in synaptic connectivity. Deleted in colorectal cancer (DCC), a receptor for the guidance cue netrin-1, plays a pivotal role in organizing neuronal circuitry by guiding growing axons and dendrites to their correct targets and by influencing synaptic connectivity. Results from experiments we previously conducted in dcc-heterozygous mice show that DCC plays a critical role in the developmental organization of the mesocorticolimbic dopamine (DA) circuitry. Furthermore we have shown that reduced expression of DCC during development and/or throughout life confers resilience to the development of schizophrenia-like DA and behavioural abnormalities. Importantly, this "protective" phenotype only emerges after puberty. Here we assess whether DCC may contribute to the risk of schizophrenia. We examined single nucleotide polymorphisms (SNPs) located in the DCC gene for association with schizophrenia using a case-control sample consisting of 556 unrelated schizophrenic patients and 208 healthy controls. We found one SNP, rs2270954, to be nominally associated with schizophrenia; patients were less likely to be heterozygous at this locus and more likely to be homozygous for the minor allele (χ(2)=9.84, df=2, nominal p=0.0071). Intriguingly, this SNP is located within the 3' untranslated region, an area known to contain a number of regulatory sequences that determine the stability and translation efficacy of mRNA. These results, together with our previous findings from studies in rodents, point at DCC as a promising novel candidate gene that may contribute to the genetic basis behind individual differences in susceptibility to schizophrenia.     

Results from a hypothesis generating case-control study: herpes family viruses and schizophrenia among military personnel

Background: Herpes family viruses can cause central nervous system inflammatory changes that can present with symptoms indistinguishable from schizophrenia and therefore are of interest in schizophrenia research. Most existing studies of herpes viruses have used small populations and postdiagnosis specimens. As part of a larger research program, we conducted a hypothesis-generating case-control study of selected herpes virus antibodies among individuals discharged from the US military with schizophrenia and pre- and postdiagnosis sera. Methods: Cases (n = 180) were servicemembers hospitalized and discharged from military service with schizophrenia. Controls, 3:1 matched on several factors, were members not discharged. The military routinely collects and stores members'' serum specimens. We used microplate enzyme immunoassay to measure immunoglobulin G (IgG) antibody levels to 6 herpes viruses in pre- and postdiagnosis specimens. Conditional logistic regression was used, and the measure of association was the hazard ratio (HR). Results: Overall, we found a significant association between human herpes virus type 6 and schizophrenia, with an HR of 1.17 (95% confidence interval [CI] = 1.04, 1.32). Women and blacks had significant negative associations with herpes simplex virus type 2 and cytomegalovirus; among blacks, there was a significant positive association with herpes simplex virus type 1. Among men, there was a HHV-6 temporal effect with an HR of 1.41 (95% CI = 1.02, 1.96) for sera drawn 6–12 months before diagnosis. Discussion: Findings from previous studies of herpes family viruses and schizophrenia have been inconsistent. Our study is based on a larger population than most previous studies and used serum specimens collected before onset of illness. This study adds to the body of knowledge and provides testable hypotheses for follow-on studies.     

Personality traits in migraine and tension-type headaches: a five-factor model study

Although abnormal personality traits have been frequently reported in patients with primary headaches, the overlaps between these domains need a clear standard definition, for example, by a five-factor personality model. Moreover, personality abnormalities in patients with episodic tension-type headache (ETH) and migraine with aura (MA) are less well studied. Therefore, we administered Zuckerman-Kuhlman's Personality Questionnaire to 72 patients suffering from chronic tension-type headaches (CTH), 33 with ETH, 15 with MA and 57 with migraine without aura (MO), as well as 58 healthy subjects. Depressive trends were measured with Plutchik-van Praag's Depression Inventory. Compared to healthy controls, the CTH, ETH and MO groups showed significantly greater neuroticism-anxiety and depression. In addition, the MO group scored significantly higher on aggression-hostility than healthy controls. No abnormal personality traits were found in patients with MA. This study, from the perspective of a five-factor model, confirms most previous reports about personality in patients with primary headaches and establishes elevated aggression-hostility only in MO sufferers.     

Fewer but heavier caffeine consumers in schizophrenia: a case-control study

According to the literature, there is an association between schizophrenia and caffeine consumption, but it is not clear whether schizophrenia is associated with either higher prevalence of daily caffeine intake or the amount consumed. In this study we compared our previously published schizophrenia patients (n=250) with a control sample (n=290) after controlling for demographic variables and tobacco and alcohol consumption. Current caffeine intake was less frequent in schizophrenia patients (59%, 147/250) than in controls (70%, 204/290). In the multivariate analyses, caffeine intake was less frequent at an older age and in schizophrenia patients, and more frequent in smokers and alcohol users. Among caffeine consumers, heavy caffeine intake (> or =200 mg/day) was significantly associated with schizophrenia (64%, 94/147 in schizophrenia versus 36%, 73/204 in controls), as well as older age and smoking. Daily amount of caffeine intake and smoked cigarettes correlated significantly in the schizophrenia group but not in the control group; the correlation of caffeine intake with nicotine dependence was low and non-significant in both groups. The association between current smoking and heavy caffeine intake may be partly explained by a pharmacokinetic effect: tobacco smoke compounds induce caffeine metabolism by the cytochrome P450 1A2. Although schizophrenia by itself may be associated with heavy caffeine intake in caffeine users, part of this association was explained by the association between schizophrenia and smoking. The relationship between caffeine and alcohol intake appeared to be more complex; alcohol and caffeine use were significantly associated, but within caffeine users alcohol was associated with less frequent heavy caffeine consumption among smokers. In future studies, the measurement of plasma caffeine levels will help both to better define heavy caffeine intake and to control for smoking pharmacokinetic effects.     

Suicide in schizophrenia: a retrospective case-control study of 51 suicides

The aim of this study was to identify factors associated with suicide in patients with schizophrenia who required inpatient admission and to compare these factors with the risk profile of patients with other diagnoses also requiring inpatient care. A retrospective, matched case-control study of 51 patients with schizophrenia requiring psychiatric inpatient care was undertaken. A priori specified risk factors were investigated within the schizophrenia group and compared with those of patients with other psychiatric diagnoses. The results show that previous suicide attempts are associated with an increased risk of suicide across all diagnoses. The presence of depressive symptoms and involvement of police with the index admission become more significant factors in patients with schizophrenia, compared to those with other diagnoses. Supportive mental health accommodation is associated with a reduced risk of suicide. Suicide of individuals is difficult to predict in patients with schizophrenia. Young men appear particularly vulnerable at times of inpatient care. Depressive symptoms and previous suicide attempts are significant risk factors.     

Accelerated leukocyte telomere erosion in schizophrenia: Evidence from the present study and a meta-analysis

Human telomeres consist of tandem nucleotide repeats (TTAGGG) and associated proteins, and telomere length (TL) is reduced progressively with cell division over the lifespan. Telomere erosion might be accelerated or prevented to varying degrees when exposure to serious medical illnesses. In previous studies, an association between TL decrease and schizophrenia has been extensively reported; however, the results remain largely controversial. To further investigate TL in schizophrenia patients and reconcile this controversy, we first measured leucocyte TL (LTL) in our samples (52 paranoid schizophrenia, 89 non-paranoid patients and 120 controls), and then conducted a comprehensive meta-analysis of the existing results of LTL in patients of schizophrenia compared to healthy subjects. Totally, 11 studies encompassing 1243 patients of schizophrenia and 1274 controls were included in the final meta-analysis model. In our samples, significant reduction of LTL in paranoid schizophrenia was observed compared to controls (F = 50.88, P < 0.001); whereas there was no significant difference in LTL between non-paranoid schizophrenia and controls (F = 0.842, P = 0.360). For meta-analysis, random-effects model showed significant LTL decrease in patients of schizophrenia when compared to controls (Z = 2.07, P = 0.039, SMD = −0.48, 95% CI = −0.94 to −0.03). Moreover, a marginal decrease in LTL was observed in medicated patients (Z = 1.92, P = 0.055, SMD = −0.58, 95% CI = −1.18–0.01) and those patients with poor response to antipsychotics (Z = 1.76, P = 0.078, SMD = −0.60, 95% CI = −1.27–0.07). In conclusion, we observed significant reduction of LTL in individuals with schizophrenia compared with controls. However, all the studies included in the meta-analysis were cross-sectional, and better controlled long-term studies are needed to replicate this result.     

Association between a functional catechol O-methyltransferase gene polymorphism and schizophrenia: meta-analysis of case-control and family-based studies

OBJECTIVE: There is strong evidence for a genetic contribution to schizophrenia, but efforts to identify susceptibility genes have been largely unsuccessful because of the low power of individual studies. The authors' goal was to evaluate the collective evidence for an association between the Val158/108Met polymorphism of the catechol O-methyltransferase (COMT) gene and schizophrenia. METHOD: They performed separate meta-analyses of existing case-control and family-based association studies. RESULTS: Overall, case-control studies showed no indication of an association between either allele and schizophrenia, and family-based studies found modest evidence implicating the Val allele in schizophrenia risk. The pooled analyses of studies from diverse geographical regions may have obscured ethnic differences in patterns of genetic risk for schizophrenia. Stratification of the studies by ethnicity of the subjects yielded evidence for an association with the Val allele in case-control studies of European samples and, especially, in family-based studies of European samples. Case-control and family-based studies of Asian samples produced mixed results and, overall, little evidence for association. CONCLUSIONS: The results of the two types of association studies diverged somewhat, but the evidence from the family-based studies, although based on fewer reports, may be more accurate. The Val allele may be a small but reliable risk factor for schizophrenia for people of European ancestry, but the influence of this polymorphism on risk in Asian populations remains unclear. These results call for more family-based studies to confirm the association between COMT and schizophrenia in European samples and to clarify its contribution to risk in Asian samples. They also suggest that case-control studies should use methods of genomic control to avoid being confounded by population stratification.