Cognitive Deficits and Clinical Symptoms with Hippocampal Subfields in First-Episode and Never-Treated Patients with Schizophrenia.

Memory dysfunction and associated hippocampal disturbances play crucial roles in cognitive impairment of schizophrenia. To examine the relationships between cognitive function and the hippocampal subfields (HSs) in first-episode never-treated (FENT) schizophrenia patients, the HSs were segmented in 39 FENT patients and 30 healthy controls using a state-of the-art automated algorithm. We found no significant differences in any HSs between the patients and controls. However, multivariate regression analysis showed that the left cornu ammonis 1 (CA1), left hippocampal tail, left presubiculum, and right molecular layer contributed 40% to the variance of the PANSS negative symptom score. After adjusting for sex, age, education, and intracranial volume, the partial correlation analysis showed that the volumes of left CA1, CA3, CA4, molecular layer, granule cell layer and both left and right subiculum were negatively correlated with the MATRICS consensus cognitive battery (MCCB) Hopkins Verbal Learning Test (HVLT). Multiple regression analysis showed that the left CA1 and CA3 hippocampal abnormalities contributed 66% to the variance of the HVLT. Our results suggest no detectable HS deficits were found in FENT schizophrenia patients. However, the HSs may be involved in the symptoms and cognitive deficits of schizophrenia patients in the early phase of their illness.

Macrophage migration inhibitory factor as a potential novel biomarker for cognitive function in patients with first-episode schizophrenia.

OBJECTIVE: Cognitive impairment is prevalent in schizophrenia. Macrophage migration inhibitory factor which is released into the circulation under stress or inflammation, is associated with cognition and also plays an important role in immunity. However, no study has investigated the relationship between macrophage migration inhibitory factor and cognitive function in first-episode schizophrenia patients at baseline or after treatment. This study investigated the pre- and post-risperidone treatment correlations between serum macrophage migration inhibitory factor levels and cognitive function in first-episode schizophrenia patients. METHODS: A total of 83 first-episode schizophrenia patients who received risperidone monotherapy and 57 healthy controls - matched for sex, age, smoking status, education (years), marital status and waist-to-hip ratio - were included. Macrophage migration inhibitory factor levels were measured before and 10 weeks after treatment in the patient group and at baseline in the controls. Pre- and post-treatment cognitive functions in patients were assessed using the MATRICS Consensus Cognitive Battery. RESULTS: At baseline, macrophage migration inhibitory factor levels were significantly higher in first-episode schizophrenia patients than those in healthy controls (p < 0.01) and decreased in patients after 10 weeks of risperidone treatment compared with baseline (p < 0.05). The MATRICS Consensus Cognitive Battery total score and the sub-scores for the Trail Making Test, Symbol Coding, Letter Number Sequence, Maze and Brief Visuospatial Memory Test-Revised improved significantly after risperidone treatment. After controlling for age, sex, education, waist-to-hip ratio and smoking status, partial correlation analysis showed a positive correlation between baseline macrophage migration inhibitory factor levels and patients' baseline MATRICS Consensus Cognitive Battery verbal memory scores (r = 0.29, p = 0.01). Macrophage migration inhibitory factor changes correlated negatively with verbal memory changes (r = -0.26, p = 0.04). Multiple linear regression analysis identified a definite correlation between the changes in word memory test score and macrophage migration inhibitory factor level (ß = -0.09, p = 0.04). CONCLUSION: Macrophage migration inhibitory factor may be involved in the process of cognitive impairment in first-episode schizophrenia and repair mechanisms following risperidone treatment.

Interaction of BDNF with cytokines in chronic schizophrenia.

Brain-derived neurotrophic factor (BDNF) interacts with cytokines. Although both BDNF and cytokines occur at abnormal levels in schizophrenia patients, their interactions have not yet been examined. We therefore compared serum BDNF, TNF-α, interleukin (IL)-2, IL-6, and IL-8 levels in 92 chronically medicated schizophrenia patients and 60 healthy controls. We correlated these serum levels within these subject groups with each other and with clinical symptoms assessed according to the Positive and Negative Syndrome Scale (PANSS). Compared to the control group, the schizophrenia patients had significantly lower BDNF and TNF-α levels, and higher IL-2, IL-6, and IL-8 levels. The patients also showed a significant positive correlation between BDNF and both IL-2 and IL-8 levels, and low BDNF and TNF-α levels together were associated with poor performance on the PANSS cognitive factor. Thus, an interaction between cytokines and neurotrophic factors may be implicated in the pathophysiology of chronic schizophrenia. In particular, the cytokine TNF-α may interact with BNDF causing cognitive impairment.

Contribution of IL-10 and its -592 A/C polymorphism to cognitive functions in first-episode drug-naive schizophrenia.

Numerous studies have shown that proinflammatory cytokines produced by immune cells in the brain have deleterious effects on cognitive functions. In contrast, IL-10, an anti-inflammatory cytokine, can be neuroprotective and prevent neuronal dysfunction. However, few studies have linked the role of IL-10 to cognitive deficits in schizophrenia. In this study, serum IL-10 levels and genotypes for the IL10 -592 A/C promoter polymorphism were measured in a cohort of first-episode drug-naïve schizophrenic patients (FEDN-S) (n=256) and healthy control subjects (HC) (n=540). All participants were assessed by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), and psychopathology was assessed by the Positive and Negative Syndrome Scale (PANSS). In a separate transcriptomic data set containing 577 healthy human brain samples, we analyzed IL-10 and IL-10 RA/B-associated genetic networks in order to ascertain potential functions for IL-10 in the brain. We found a significant difference in allelic frequency between FEDN-S and HC subjects. The A allelic variant was associated with reduced serum IL-10 levels and worse attentional performance in FEDN-S but not in HC subjects. Moreover, serum IL-10 levels were correlated with the extent of cognitive impairment, especially attentional performance in the schizophrenic A-allele carriers. In human brain transcriptomic coexpression analysis, we found that genes most significantly co-expressed with IL10 were associated with synaptic vesicle transportation, and both IL10RA and IL10RB were most significantly co-expressed not only with genes that regulate inflammation but also with those that participate in synaptic formation. The IL10-592 A/C genetic variant was more common in schizophrenic patients than HC and was associated with lower IL-10 serum levels and worse attentional performance in these patients. Furthermore, the IL10 gene and its receptors in the healthy human brain appear to regulate inflammation and synaptic functions that are important for cognition, and hence its deficiency in schizophrenia may contribute to cognitive impairment.

Association of the manganese superoxide dismutase gene Ala-9Val polymorphism with age of smoking initiation in male schizophrenia smokers.

Schizophrenia patients exhibit higher smoking rates than the general population. A growing body of evidence suggests that cigarette smoke impairs the antioxidant defense mechanisms, leading to oxidative damage. Manganese superoxide dismutase (MnSOD) is the major antioxidant in the mitochondria, catalyzing the metabolism of superoxide radicals to form hydrogen peroxide. Since the identification of a well-characterized functional polymorphism, Ala-9Val of MnSOD, a number of studies have evaluated the association between Val-9Ala and schizophrenia or cancer. In this study, we hypothesized that the functional polymorphism of MnSOD Ala-9Val was associated with smoking in patients with schizophrenia. This polymorphism was genotyped in 666 chronic male schizophrenia patients (smoker/never-smoker = 507/159) and 660 male controls (smoker/never-smoker = 360/300) using a case-control design. The cigarettes smoked per day (CPD) and smoking behaviors were evaluated by clinician-administered questionnaires and the Fagerstrom Test for Nicotine Dependence (FTND). The results showed no significant differences in MnSOD Ala-9Val genotype and allele distributions between the patients and healthy controls or between smokers and never-smokers in either patients or healthy controls alone. The smokers with the Ala allele started smoking significantly earlier (19.9 ± 5.8 vs. 21.7 ± 6.5 years, P = 0.005) only in patients. These results suggest that the MnSOD Ala-9Val polymorphism may not influence smoking status in a Chinese male schizophrenia population, but may influence the age at which smoking is started among schizophrenia smokers.

Mn-superoxide dismutase activity is associated with orofacial involuntary movements in schizophrenia patients with tardive dyskinesia.

BACKGROUND: Oxidative stress-induced damage may be involved in tardive dyskinesia (TD) development. Superoxide dismutase (SOD), the key antioxidant enzyme, was found abnormal in TD. OBJECTIVE: We examined the role of oxidative stress in relation to TD and TD subtypes in schizophrenia using manganese SOD (MnSOD) as the biomarker. METHODS: We recruited 152 male chronic patients with (n = 76) and without TD (n = 76) meeting Diagnostic and Statistical Manual of Mental Disorders-IV criteria for schizophrenia and 75 male control subjects. We examined the MnSOD activity for all subjects. Positive and Negative Syndrome Scale and the Abnormal Involuntary Movement Scale (AIMS) were assessed in the patients. RESULTS: Manganese SOD activity was lower in patients with TD than non-TD (p < 0.05). In the patients with TD, orofacial and total scores of AIMS were positively associated with MnSOD levels (both p < 0.05). Multiple regression analysis further confirmed that MnSOD was an independent contributor to both the orofacial and the total scores of AIMS (both p < 0.05). CONCLUSIONS: Oxidative stress reflected by compromised oxidative defense may play a role in the development and severity of TD. There may be an etiologic relationship between increased SOD level and dyskinetic movements associated with TD. In particular, MnSOD activity may have a specific role in orofacial TD.

Association of angiotensin-converting enzyme gene polymorphism with schizophrenia and depressive symptom severity in a Chinese population.

BACKGROUND: Depressive symptoms are frequently observed in schizophrenia patients. Angiotensin-converting enzyme (ACE), a key enzyme of renin-angiotensin system, can catalyze the degradation of neuropeptides and modulate dopaminergic and serotonergic neurotransmission. Previous studies have revealed the association of the ACE gene insertion/deletion polymorphism with depressive disorder and its treatment response but not with the depressive symptoms in schizophrenia. OBJECTIVE: The aim of this study is to examine whether this polymorphism was associated with susceptibility to schizophrenia and with its psychopathological symptoms, especially depressive symptoms in a Han Chinese population. METHODS: This polymorphism was genotyped in 382 chronic patients and 538 healthy controls. Psychopathology was characterised using the positive and negative syndrome scale. RESULTS: The allelic and genotypic frequencies of this polymorphism significantly differed between patients and controls (both p < 0.001). A significant difference in the positive and negative syndrome scale depressive symptom score was observed among the three genotypes (p < 0.03), with higher score in patients with insertion/insertion (I/I) than with deletion/deletion (D/D) genotypes (p < 0.05). Furthermore, there was a significant linear correlation between the number of I alleles and the depressive symptom score (p < 0.05). CONCLUSIONS: The ACE gene insertion/deletion polymorphism may play a role in susceptibility to schizophrenia and also in its depressive symptom severity in a Han Chinese population.

Association between the angiotensin-converting enzyme gene insertion/deletion polymorphism and first-episode patients with schizophrenia in a Chinese Han population.

BACKGROUND: Angiotensin-converting enzyme (ACE), a key enzyme of the renin-angiotensin system, can modulate dopamine turnover in the midbrain. Previous studies have revealed an association between ACE gene insertion/deletion (I/D) polymorphism and chronic schizophrenia, yet results are conflicting. OBJECTIVE: The primary objective of this study was to examine whether the ACE gene I/D polymorphism is associated with first-episode patients with schizophrenia (FEP) in a Chinese Han population. METHODS: The presence of the polymorphism was determined in 220 FEP and 538 healthy controls using a case-control design. We assessed the psychopathology in 212 FEP using the Positive and Negative Syndrome Scale (PANSS). RESULTS: The allelic and genotypic frequencies of the ACE gene I/D polymorphism did not significantly differ between FEP and healthy controls (both p>0.05). However, the negative PANSS symptom was significantly higher in FEP with the D/D genotype than those with I/D and I/I genotypes (all p<0.05) even after Bonferroni corrections (all p<0.05). Furthermore, the D allele of the ACE gene was associated with higher negative PANSS symptom score in FEP. CONCLUSIONS: Our results indicated that even though the ACE gene I/D polymorphism did not associate with FEP, it may play a role in susceptibility to the negative PANSS symptom of FEP in a Chinese Han population.

Efficacy and safety of prolonged-release trazodone in major depressive disorder: a multicenter, randomized, double-blind, flexible-dose trial.

OBJECTIVE: To investigate the efficacy, safety, and clinical benefit of prolonged-release trazodone (Trittico) in the treatment of major depressive disorder (MDD). METHODS: In this study, 363 Chinese patients with MDD were randomized 1:1 to receive either prolonged-release trazodone (150-450 mg) or placebo treatment for 6 weeks. The primary efficacy measurement was the change of the 17-item Hamilton Depression Rating Scale (HAMD-17) total score from baseline to the end of the study. The secondary efficacy measurements were the response and remission rates, the Clinical Global Impression - Improvement of Illness (CGI-I) score at the end of the study, and the change of the HAMD-14 total score and quality of sleep [evaluated by the Pittsburgh Sleep Quality Index (PSQI) scale] during the study period. RESULTS: The mean maximum daily dose was 273.11 mg for the trazodone group and 290.92 mg for the placebo group. At the end of the study, there was a significant difference between the two groups in the HAMD-17 change score (trazodone vs. placebo: -11.07 vs. -8.29, p < 0.001). Trazodone showed advantages at 1 week of treatment, and the effect lasted until the end of the study (week 6). The response and remission rates of the trazodone group were significantly higher than those in the placebo group (response rate: 59.6 vs. 37.2%, p < 0.001; remission rate: 35.5 vs. 22.2%, p = 0.005). The majority of the adverse reactions of trazodone were mild to moderate, and the most frequent adverse reactions (≥5%) were dizziness, dry mouth, somnolence, and nausea. CONCLUSIONS: Prolonged-release trazodone was more effective than placebo in MDD and was well tolerated.

A double-blind, randomized controlled study of the effects of celecoxib on clinical symptoms and cognitive impairment in patients with drug-naïve first episode schizophrenia: pharmacogenetic impact of cyclooxygenase-2 functional polymorphisms.

Chronic low-grade peripheral and central nervous system inflammation may have a role in the pathogenesis of schizophrenia (SCZ). Inhibition of cyclooxygenase-2 (COX2), the arachidonic acid pathway, may inhibit cytokine responses and minimize inflammation. In this study, we added the COX2 inhibitor celecoxib to risperidone monotherapy to examine its efficacy on clinical symptoms and cognitive deficits in drug-naïve first episode (DNFE) SCZ patients. First, we genotyped two polymorphisms (rs5275 and rs689466) in the COX-2 gene in a case-control study of 353 SCZ patients and 422 healthy controls. Ninety patients participated in a 12-week, double-blind, randomized, placebo-controlled trial of celecoxib 400 mg/day. We used the Positive and Negative Syndrome Scale (PANSS) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) to assess clinical symptoms and cognition. Our results show that the COX2 rs5275 polymorphism was significantly correlated with SCZ and positive symptoms. After 12-week treatment, celecoxib significantly improved the PANSS total and three subscale scores of SCZ patients. Furthermore, patients with the rs5275 TT genotype had greater improvement in PANSS total score than patients carrying the C allele. However, no significant difference in RBANS total and subscale scores existed between the celecoxib and placebo groups at week 12. Our findings suggest that COX2 inhibitors may be promising therapeutics for clinical symptoms rather than cognitive impairment in first episode SCZ patients. COX2 rs5275 gene polymorphism may be implicated in the development and the efficacy of treating clinical symptoms in SCZ.Trial Registration Number: The trial was registered with www.clinicaltrials.gov (NCT00686140).

Association between suicidal behavior and impaired glucose metabolism in first-episode drug-naïve patients with schizophrenia.

BACKGROUND: Schizophrenia (SZ) patients have been reported to have comorbid suicidal behavior (SB) and impaired glucose metabolism in early psychosis, but it is unclear whether impaired glucose metabolism plays a role in the occurrence of SB in patients with first-episode drug-naïve (FEDN) SZ. Therefore, our main aim was to examine the relationship between SB and glucose metabolism in FEDN SZ patients. METHODS: We recruited 319 FEDN SZ patients and collected information on their sociodemographic characteristics, clinical data, and glucose metabolism parameters. Participants' psychotic and depressive symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS) and the Hamilton Depression Rating Scale (HAMD), respectively. Fasting plasma glucose and insulin levels were also measured. RESULTS: The percentage of FEDN SZ patients with SB was 45.5% (145/319). Compared to SZ patients without SB, SZ patients with SB exhibited higher scores on HAMD, PANSS positive subscale, as well as higher levels of fasting plasma glucose, fasting plasma insulin, and homeostasis model assessment of insulin resistance index (all p<0.05). Logistic regression analysis indicated that increased levels of insulin resistance (adjusted OR = 1.920), body mass index (adjusted OR = 0.931), and PANSS general psychopathology (adjusted OR = 1.041) were independently associated with SB. The Receiver Operating Characteristic Curve showed an Area Under Curve value of 0.732 for the combination of three factors in regression model to distinguish between SB and non-SB. CONCLUSIONS: Our results indicate that fasting glucose, fasting insulin, and insulin resistance are strongly associated with SB in FEDN SZ patients, suggesting that glucose metabolism abnormalities may be potential biomarkers of SB in SZ patients. Regular monitoring of glucose metabolism variables is essential for suicide prevention.

Interleukin 18 and cognitive impairment in first episode and drug naïve schizophrenia versus healthy controls.

Alterations in the inflammatory and immune systems have been documented to occur from the earliest stages of schizophrenia, and have been associated with neurodevelopmental changes. Cognitive impairment is a core feature in the pathology of schizophrenia, and recent studies showed a significant increase in serum IL-18 in schizophrenia, and a putative role of IL-18 in neuroprogression and thus neurocognitive defects. The purpose of this study was to examine the association of IL-18 with cognitive deficits in schizophrenia. We recruited 77 first episode and drug naïve schizophrenic patients and 75 healthy control subjects and examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and serum IL-18 in both groups. Schizophrenic symptoms were assessed using the positive and negative syndrome scale (PANSS). We found that IL-18 levels were non-significantly higher in patients than controls (206.0±92.9 pg/ml vs 193.2±41.8 pg/ml, p=0.28). Cognitive scores on the RBANS and nearly all of its five subscales (all p<0.05) except for the Visuospatial/Constructional index (p>0.05) were significantly lower in schizophrenic patients than normal controls. For the patients, IL-18 was positively associated with the Visuospatial/Constructional domain of cognitive deficits in schizophrenia. Our findings suggest that cognitive deficits occur during the acute stage of a schizophrenic episode, and IL-18 may be involved in Visuospatial/Constructional deficits of these patients.

Association of BDNF gene polymorphisms with schizophrenia and clinical symptoms in a Chinese population.

The neurodevelopmental hypothesis is well established in schizophrenia. Accumulating evidence has shown that BDNF may be involved in the pathogenesis of schizophrenia. This study aimed to investigate the potential association of BDNF gene polymorphisms with susceptibility to schizophrenia and with the psychopathological symptoms in patients with schizophrenia in a Han Chinese population. Three polymorphisms (rs6265, rs12273539, and rs10835210) of the BDNF gene were analyzed in a case-control study of 709 Han Chinese individuals (375 patients and 334 controls). The patients' psychopathology was assessed using the positive and negative syndrome scale (PANSS). We found no significant differences in the genotype and allele distributions of all three polymorphisms between the patient and control groups; however, we found a trend toward to significant overall difference in the estimated haplotype frequencies, with more frequent haplotype ATC of rs6265-rs12273539-rs10835210 in the schizophrenic patients than in controls (P = 0.027). The quantitative trait analysis by the UNPHASED program showed significant associations between the rs6265 (A)-rs12273539 (C)-rs10835210 (A) haplotype and negative symptom scores from the PANSS (x(2) = 5.79, P = 0.016). Our findings suggest that the BDNF gene polymorphisms may play a small effect on susceptibility to schizophrenia, but may contribute to the negative symptoms of the disease.

Smoking affects the association between cognitive impairment and P50 inhibition defects in patients with chronic schizophrenia: A case-control study.

OBJECTIVE: Smoking affects sensory gating, as assessed by the event related potential P50, which is evoked by auditory stimuli and is considered to be involved in the pathophysiology of schizophrenia (SCZ). However, few studies have compared sensory gating and cognitive performance between smoking and non-smoking SCZ patients in the Chinese Han population. METHODS: We recruited two groups of Chinese subjects: 128 male chronic SCZ patients and 76 male healthy controls, measuring cognition with the MATRICS Consensus Cognitive Battery (MCCB) and sensory gating with the P50 EEG components. Based on their smoking status, they were further divided into 4 subgroups: smoking SCZ patients, non-smoking SCZ patients, smoking healthy controls, and non-smoking healthy controls. We assessed psychopathological symptoms of the patients using the Positive and Negative Syndrome Scale (PANSS). RESULTS: Compared with healthy controls, SCZ patients had lower MCCB total score and scores of all 10 tests (all p < 0.05), while SCZ patients had higher S2 amplitudes and P50 ratios (both p < 0.05). When comparing smoking versus non-smoking SCZ patients, non-smokers had significantly better spatial span (p < 0.05). Furthermore, the S1 amplitude was negatively correlated with the Brief Visuospatial Memory Test (BVMT-R) in smoking patients (p < 0.05), while the S1 latency was negatively correlated with spatial span in non-smoking patients (p < 0.01). CONCLUSIONS: Our finding shows a difference in the relationship between sensory gated P50 and cognition in smoking and non-smoking SCZ patients, suggesting that nicotine may improve cognitive and P50 deficits in SCZ patients.

Cognitive and serum BDNF correlates of BDNF Val66Met gene polymorphism in patients with schizophrenia and normal controls.

Studies suggest that a functional polymorphism of the brain-derived neurotrophic factor gene (BDNF Val66Met) may mediate hippocampal-dependent cognitive functions. A few studies have reported its role in cognitive deficits in schizophrenia including its association with peripheral BDNF levels as a mediator of these cognitive deficits. We assessed 657 schizophrenic inpatients and 445 healthy controls on the repeatable battery for the assessment of neuropsychological status (RBANS), the presence of the BDNF Val66Met polymorphism and serum BDNF levels. We assessed patient psychopathology using the Positive and Negative Syndrome Scale. We showed that visuospatial/constructional abilities significantly differed by genotype but not genotype × diagnosis, and the Val allele was associated with better visuospatial/constructional performance in both schizophrenic patients and healthy controls. Attention performance showed a significant genotype by diagnosis effect. Met allele-associated attention impairment was specific to schizophrenic patients and not shown in healthy controls. In the patient group, partial correlation analysis showed a significant positive correlation between serum BDNF and the RBANS total score. Furthermore, the RBANS total score showed a statistically significant BDNF level × genotype interaction. We demonstrated an association between the BDNF Met variant and poor visuospatial/constructional performance. Furthermore, the BDNF Met variant may be specific to attentional decrements in schizophrenic patients. The association between decreased BDNF serum levels and cognitive impairment in schizophrenia is dependent on the BDNF Val66Met polymorphism.

Rater evaluations for psychiatric instruments and cultural differences: the positive and negative syndrome scale in China and the United States.

This article compares Positive and Negative Syndrome Scale (PANSS) data from Chinese and American inpatients with chronic schizophrenia to show how differences in item ratings may reflect cultural attitudes of raters. The Chinese sample (N = 504) came from Beijing Huilongguan Hospital. The American sample came from 268 PANSS assessments of Clinical Antipsychotic Trials of Intervention Effectiveness subjects hospitalized for 15 days or more to optimize equivalence of the samples. When controlling for age and sex, the Chinese sample scored significantly lower for total score by 25% (p < 0.0001), for the positive subscale by 35% (p < 0.0001), and on the general subscale by 32% (p < 0.0001) but not significantly different on the negative subscale score (+0.26%; p = 0.76). However, the Chinese sample scored 26% higher on the item on poor rapport (p < 0.0001), 10.2% higher on passive social withdrawal (p = 0.003), and most notably 46% higher on the item on lack of judgment and insight (p < 0.0001). These results remain broadly consistent across sex subgroup analyses. Differences seem to be best explained by both cultural differences in patient clinical presentations and varying American and Chinese cultural values affecting rater judgment.

The relationship between cognitive impairment and superoxide dismutase activity in untreated first-episode patients with schizophrenia.

Objectives: Cognitive decline is an essential characteristic of schizophrenia and may be due to the disturbance between reactive oxygen species generation and antioxidant capacity. The study aimed to explore the association between cognitive deficits and antioxidant defence parameters in untreated first-episode patients with schizophrenia.Methods: We determined important antioxidant enzymes, total superoxide dismutase (SOD) and manganese SOD (MnSOD), and their relationship with cognitive impairment in 168 untreated patients with first-episode schizophrenia and 168 age- and sex-matched healthy controls. The evaluation of psychopathological symptoms of all patients was based on the Positive and Negative Syndrome Scale (PANSS). We measured cognitive function by the Repeated Battery for the Assessment of Neuropsychological Status (RBANS) and activities of total SOD and MnSOD in all participants.Results: The results showed that untreated patients with first-episode schizophrenia had deficient cognitive functioning in four RBANS indices and total scores, except for the visuospatial/constructional index, as well as higher plasma total SOD activity compared with the control subjects. In addition, significant negative correlations were identified between MnSOD activity and attention index or RBANS total score in patients.Conclusions: Our results suggest that oxidative stress may be partly responsible for cognitive dysfunction in the early course of schizophrenia.

Gender differences in the prevalence of diabetes mellitus in chronic hospitalized patients with schizophrenia on long-term antipsychotics.

Gender-specific relationships between diabetes mellitus (DM) and schizophrenia have previously received little systematic study. The results showed that the overall DM prevalence was 20% with rates of 17% (58/343) in males and 27% (46/172) in females (p<0.01). Furthermore, increased body mass index (BMI), abdominal obesity and antipsychotic types were predictors of diabetes in these chronic schizophrenic patients.

The prevalence and clinical-demographic correlates of diabetes mellitus in chronic schizophrenic patients receiving clozapine.

OBJECTIVE: To examine the prevalence and correlates of diabetes in a large sample of Chinese patients with schizophrenia on long-term clozapine treatment, because this population previously has received little systematic study. METHODS: Two hundred and six inpatients meeting Diagnostic and Statistical Manual of Mental Disorders, 4th Edition schizophrenia criteria were recruited in a cross-sectional naturalistic study, and compared with 615 healthy control subjects matched for age, sex, education, and body mass index (BMI). The patient's psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS). Diagnoses of diabetes were established through review of medical records and fasting blood glucose testing, or an oral glucose tolerance test. RESULTS: Diabetes mellitus was more common in patients than in the normal controls (22.3% vs 6.2%) (odds ratio = 4.37, confidence interval (CI) 2.76-6.92, p < 0.001). The prevalence of diabetes increased with age across five age-groups as compared with normal controls (X(2) = 18.0, df = 4, p = 0.001). The PANSS total score and sub-scores showed no differences between the diabetic and non-diabetic groups. Logistic regression in the patients revealed significant associations between diabetes and a family history of diabetes (p < 0.001), age (p < 0.01), and BMI (p < 0.05). CONCLUSION: Long-term clozapine treatment was associated with an increased and clinically important risk of diabetes mellitus in Chinese chronic schizophrenic patients, which is consistent with previous reports in Western populations.

Sex differences in the association between symptoms and superoxide dismutase in patients with never-treated first-episode schizophrenia.

OBJECTIVES: Considering the sex differences and oxidative stress in the pathophysiological mechanism of schizophrenia (SCZ), we explored the sex differences in clinical characteristics and superoxide dismutase (SOD) activity as well as their relationship in never-treated first-episode (NTFE) patients with SCZ in the Han Chinese population, which has not been reported yet. METHODS: Total SOD and manganese SOD (MnSOD) activities were examined in 165 NTFE patients with SCZ (male/female = 98/67) and 133 healthy controls (male/female =70/63). Psychopathological symptoms were evaluated by a five-factor model of the Positive and Negative Syndrome Scale (PANSS). RESULTS: SCZ patients had higher plasma total SOD activity than healthy controls (p < .01). In healthy controls, the total SOD activity was significantly higher in males than that in females (p < .001), but not in patients group (p > .05). Further, Multiple regression analysis revealed that in male patients, the PANSS depressive factor was independently positively correlated with MnSOD or total SOD activity (both p < .01), while in female patients, the MnSOD activity was positively related to the PANSS positive symptom score (p < .05). CONCLUSIONS: Our findings indicate sex differences in the relationship between SOD activities and psychopathological symptoms in the early stage of SCZ.