Deficit schizophrenia: association with serum antibodies to cytomegalovirus

French Validation of the Brief Negative Symptom Scale (BNSS)

ObjectivesThis study aims to validate the French version of the Brief Negative Symptom Scale (BNSS) by assessing its psychometric properties in a population of patients with schizophrenia or schizoaffective disorder.Methods73 patients with schizophrenia or schizoaffective disorder were included. Participants were evaluated using the BNSS, the Positive and Negative Syndrome Scale (PANSS), and the Self-Evaluation of Negative Symptoms (SNS). The internal consistency of the BNSS was measured using Cronbach's alpha, structural validity was assessed through exploratory factor analysis, and construct validity was evaluated with Spearman correlations between BNSS scores, the negative subscale of the PANSS, the total SNS score, the positive subscale of the PANSS, and PANSS items evaluating insight and depressive mood.ResultsThe internal consistency of the BNSS was excellent (Cronbach's alpha = 0.93). Exploratory factor analysis revealed two factors corresponding to the motivational and expressive dimensions of negative symptoms. Significant positive correlations were found between total BNSS scores and the negative subscale of the PANSS (Rho = 0.77; p < 0.001), as well as with SNS scores (Rho = 0.55; p < 0.001). No correlation was observed between total BNSS scores and the positive subscales of the PANSS (Rho = 0.09; p = 0.41). However, significant positive correlations were noted with the PANSS item assessing depression (Rho = 0.28; p = 0.015) and insight (Rho = 0.43; p < 0.001).ConclusionThe French version of the BNSS has demonstrated strong psychometric properties and is suitable for clinical and research use.Plain Language Summary TitleValidation d'une échelle d'évaluation des symptômes négatifs, la « Brief Negative Symptom Scale » (BNSS).

Human endogenous retroviruses type W (HERV-) activation and schizophrenia: A meta-analysis

OBJECTIVE

Human endogenous retroviruses (HERV) are the remnants of infections that occurred million years ago. They gradually integrated into the human genome, comprising 8 % of it. There are growing reports suggesting their potential role in various diseases, including schizophrenia. Schizophrenia, a serious psychiatric disorder, is caused by the interaction of genetic and environmental factors. In the present paper, we investigated studies focusing on the association between schizophrenia and HERV-W.

METHODS

We registered this study at PROSPERO (registration number: CRD42022301122). The entire steps of this study were based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. We searched PubMed, Scopus, Web of Science, and Google Scholar up to 1 August 2022. Heterogeneity was estimated through I2 statistics, and the association was measured using the first estimate and penalization methods.

RESULTS

Finally, 13 eligible studies were analyzed, including 698 cases and 728 controls. The overall odds ratio indicated a significant association in both the first estimate (OR = 9.34, 95 % CI = 4.92-17.75; P = 0.002) and penalization (OR = 7.38, 95 % CI = 4.15-13.10; P = 0.003) methods. In the subgroup analysis, among HERV-W fragments, the HERV-W envelope protein or RNA (OR = 11.41, 95 % CI: 5.67-22.97; P = 0.03) showed the strongest association with schizophrenia.

CONCLUSION

Our meta-analysis showed that HERV-W is significantly associated with schizophrenia. More studies are required to determine the pathophysiological mechanism and the diagnostic, prognostic, and therapeutic value of HERV-W in schizophrenia.

The anti-viral immune response of the adult host robustly modulates neural stem cell activity in spatial, temporal, and sex-specific manners

Viruses induce a wide range of neurological sequelae through the dysfunction and death of infected cells and persistent inflammation in the brain. Neural stem cells (NSCs) are often disturbed during viral infections. Although some viruses directly infect and kill NSCs, the antiviral immune response may also indirectly affect NSCs. To better understand how NSCs are influenced by a productive immune response, where the virus is successfully resolved and the host survives, we used the CD46+ mouse model of neuron-restricted measles virus (MeV) infection. As NSCs are spared from direct infection in this model, they serve as bystanders to the antiviral immune response initiated by selective infection of mature neurons. MeV-infected mice showed distinct regional and temporal changes in NSCs in the primary neurogenic niches of the brain, the hippocampus and subventricular zone (SVZ). Hippocampal NSCs increased throughout the infection (7 and 60 days post-infection; dpi), while mature neurons transiently declined at 7 dpi and then rebounded to basal levels by 60 dpi. In the SVZ, NSC numbers were unchanged, but mature neurons declined even after the infection was controlled at 60 dpi. Further analyses demonstrated sex, temporal, and region-specific changes in NSC proliferation and neurogenesis throughout the infection. A relatively long-term increase in NSC proliferation and neurogenesis was observed in the hippocampus; however, neurogenesis was reduced in the SVZ. This decline in SVZ neurogenesis was associated with increased immature neurons in the olfactory bulb in female, but not male mice, suggesting potential migration of newly-made neurons out of the female SVZ. These sex differences in SVZ neurogenesis were accompanied by higher infiltration of B cells and greater expression of interferon-gamma and interleukin-6 in female mice. Learning, memory, and olfaction tests revealed no overt behavioral changes after the acute infection subsided. These results indicate that antiviral immunity modulates NSC activity in adult mice without inducing gross behavioral deficits among those tested, suggestive of mechanisms to restore neurons and maintain adaptive behavior, but also revealing the potential for robust NSC disruption in subclinical infections.

Viral Infections and Schizophrenia: A Comprehensive Review

Schizophrenia is a complex mental disorder with multiple genetic and environmental factors contributing to its pathogenesis. Viral infections have been suggested to be one of the environmental factors associated with the development of this disorder. We comprehensively review all relevant published literature focusing on the relationship between schizophrenia and various viral infections, such as influenza virus, herpes virus 1 and 2 (HSV-1 and HSV-2), cytomegalovirus (CMV), Epstein-Barr virus (EBV), retrovirus, coronavirus, and Borna virus. These viruses may interfere with the normal maturation of the brain directly or through immune-induced mediators, such as cytokines, leading to the onset of schizophrenia. Changes in the expression of critical genes and elevated levels of inflammatory cytokines have been linked to virally-induced infections and relevant immune activities in schizophrenia. Future research is necessary to understand this relationship better and provide insight into the molecular mechanisms underlying the pathophysiology of schizophrenia.

Copy Number Variations and Schizophrenia

Schizophrenia is a neurodevelopmental disorder with genetic and environmental factors involved in its aetiology. Genetic liability contributing to the development of schizophrenia is a subject of extensive research activity, as reliable data regarding its aetiology would enable the improvement of its therapy and the development of new methods of treatment. A multitude of studies in this field focus on genetic variants, such as copy number variations (CNVs) or single-nucleotide variants (SNVs). Certain genetic disorders caused by CNVs including 22q11.2 microdeletion syndrome, Burnside-Butler syndrome (15q11.2 BP1-BP2 microdeletion) or 1q21.1 microduplication/microdeletion syndrome are associated with a higher risk of developing schizophrenia. In this article, we provide a unifying framework linking these CNVs and their associated genetic disorders with schizophrenia and its various neural and behavioural abnormalities.

Executive Functions and Psychopathology Dimensions in Deficit and Non-Deficit Schizophrenia

This study: (a) compared executive functions between deficit (DS) and non-deficit schizophrenia (NDS) patients and healthy controls (HC), controlling premorbid IQ and level of education; (b) compared executive functions in DS and NDS patients, controlling premorbid IQ and psychopathological symptoms; and (c) estimated relationships between clinical factors, psychopathological symptoms, and executive functions using structural equation modelling. Participants were 29 DS patients, 44 NDS patients, and 39 HC. Executive functions were measured with the Mazes Subtest, Spatial Span Subtest, Letter Number Span Test, Color Trail Test, and Berg Card Sorting Test. Psychopathological symptoms were evaluated with the Positive and Negative Syndrome Scale, Brief Negative Symptom Scale, and Self-evaluation of Negative Symptoms. Compared to HC, both clinical groups performed poorer on cognitive flexibility, DS patients on verbal working memory, and NDS patients on planning. DS and NDS patients did not differ in executive functions, except planning, after controlling premorbid IQ and negative psychopathological symptoms. In DS patients, exacerbation had an effect on verbal working memory and cognitive planning; in NDS patients, positive symptoms had an effect on cognitive flexibility. Both DS and NDS patients presented deficits, affecting the former to a greater extent. Nonetheless, clinical variables appeared to significantly affect these deficits.

Effect of Cytomegalovirus Infection on the Central Nervous System: Implications for Psychiatric Disorders

Cytomegalovirus (CMV) is a common herpesvirus that establishes lifelong latent infections and interacts extensively with the host immune system, potentially contributing to immune activation and inflammation. Given its proclivity for infecting the brain and its reactivation by inflammatory stimuli, CMV is well known for causing central nervous system complications in the immune-naïve (e.g., in utero) and in the immunocompromised (e.g., in neonates, individuals receiving transplants or cancer chemotherapy, or people living with HIV). However, its potentially pathogenic role in diseases that are characterized by more subtle immune dysregulation and inflammation such as psychiatric disorders is still a matter of debate. In this chapter, we briefly summarize the pathogenic role of CMV in immune-naïve and immunocompromised populations and then review the evidence (i.e., epidemiological studies, serological studies, postmortem studies, and recent neuroimaging studies) for a link between CMV infection and psychiatric disorders with a focus on mood disorders and schizophrenia. Finally, we discuss the potential mechanisms through which CMV may cause CNS dysfunction in the context of mental disorders and conclude with a summary of the current state of play as well as potential future research directions in this area.

Immune System Abnormalities in Schizophrenia: An Integrative View and Translational Perspectives

The immune system is generally known to be the primary defense mechanism against pathogens. Any pathological conditions are reflected in anomalies in the immune system parameters. Increasing evidence suggests the involvement of immune dysregulation and neuroinflammation in the pathogenesis of schizophrenia. In this systematic review, we summarized the available evidence of abnormalities in the immune system in schizophrenia. We analyzed impairments in all immune system components and assessed the level of bias in the available evidence. It has been shown that schizophrenia is associated with abnormalities in all immune system components: from innate to adaptive immunity and from humoral to cellular immunity. Abnormalities in the immune organs have also been observed in schizophrenia. Evidence of increased C-reactive protein, dysregulation of cytokines and chemokines, elevated levels of neutrophils and autoantibodies, and microbiota dysregulation in schizophrenia have the lowest risk of bias. Peripheral immune abnormalities contribute to neuroinflammation, which is associated with cognitive and neuroanatomical alterations and contributes to the pathogenesis of schizophrenia. However, signs of severe inflammation are observed in only about 1/3 of patients with schizophrenia. Immunological parameters may help identify subgroups of individuals with signs of inflammation who well respond to anti-inflammatory therapy. Our integrative approach also identified gaps in knowledge about immune abnormalities in schizophrenia, and new horizons for the research are proposed.

Dissecting Molecular Genetic Mechanisms of 1q21.1 CNV in Neuropsychiatric Disorders

Pathogenic copy number variations (CNVs) contribute to the etiology of neurodevelopmental/neuropsychiatric disorders (NDs). Increased CNV burden has been found to be critically involved in NDs compared with controls in clinical studies. The 1q21.1 CNVs, rare and large chromosomal microduplications and microdeletions, are detected in many patients with NDs. Phenotypes of duplication and deletion appear at the two ends of the spectrum. Microdeletions are predominant in individuals with schizophrenia (SCZ) and microcephaly, whereas microduplications are predominant in individuals with autism spectrum disorder (ASD) and macrocephaly. However, its complexity hinders the discovery of molecular pathways and phenotypic networks. In this review, we summarize the recent genome-wide association studies (GWASs) that have identified candidate genes positively correlated with 1q21.1 CNVs, which are likely to contribute to abnormal phenotypes in carriers. We discuss the clinical data implicated in the 1q21.1 genetic structure that is strongly associated with neurodevelopmental dysfunctions like cognitive impairment and reduced synaptic plasticity. We further present variations reported in the phenotypic severity, genomic penetrance and inheritance.

Terminology and assessment tools of psychosis: A systematic narrative review

AIM

Phenomena within the psychosis continuum that varies in frequency/duration/intensity have been increasingly identified. Different terms describe these phenomena, however there is no standardization within the terminology. This review evaluated the definitions and assessment tools of seven terms - (i) 'psychotic experiences'; (ii) 'psychotic-like experiences'; (iii) 'psychotic-like symptoms'; (iv) 'attenuated psychotic symptoms'; (v) 'prodromal psychotic symptoms'; (vi) 'psychotic symptomatology'; and (vii) 'psychotic symptoms'.

METHODS

EMBASE, MEDLINE, and CINAHL were searched during February-March 2019. Inclusion criteria included 1989-2019, full text, human, and English. Papers with no explicit definition or assessment tool, duplicates, conference abstracts, systematic reviews, meta-analyses, or no access were excluded.

RESULTS

A total of 2238 papers were identified and of these, 627 were included. Definitions and assessment tools varied, but some trends were found. Psychotic experiences and psychotic-like experiences were transient and mild, found in the general population and those at-risk. Psychotic-like symptoms were subthreshold and among at-risk populations and non-psychotic mental disorders. Attenuated psychotic symptoms were subthreshold but associated with distress, risk, and help-seeking. Prodromal psychotic symptoms referred to the prodrome of psychotic disorders. Psychotic symptomatology included delusions and hallucinations within psychotic disorders. Psychotic symptoms was the broadest term, encompassing a range of populations but most commonly involving hallucinations, delusions, thought disorder, and disorganization.

DISCUSSION

A model for conceptualizing the required terms is proposed and future directions needed to advance this field of research are discussed.

A Peptide Link Between Human Cytomegalovirus Infection, Neuronal Migration, and Psychosis

Alongside biological, psychological, and social risk factors, psychotic syndromes may be related to disturbances of neuronal migration. This highly complex process characterizes the developing brain of the fetus, the early postnatal brain, and the adult brain, as reflected by changes within the subventricular zone and the dentate gyrus of the hippocampus, where neurogenesis persists throughout life. Psychosis also appears to be linked to human cytomegalovirus (HCMV) infection. However, little is known about the connection between psychosis, HCMV infection, and disruption of neuronal migration. The present study addresses the hypothesis that HCMV infection may lead to mental disorders through mechanisms of autoimmune cross-reactivity. Searching for common peptides that underlie immune cross-reactions, the analyses focus on HCMV and human proteins involved in neuronal migration. Results demonstrate a large overlap of viral peptides with human proteins associated with neuronal migration, such as ventral anterior homeobox 1 and cell adhesion molecule 1 implicated in GABAergic and glutamatergic neurotransmission. The present findings support the possibility of immune cross-reactivity between HCMV and human proteins that-when altered, mutated, or improperly functioning-may disrupt normal neuronal migration. In addition, these findings are consistent with a molecular and mechanistic framework for pathological sequences of events, beginning with HCMV infection, followed by immune activation, cross-reactivity, and neuronal protein variations that may ultimately contribute to the emergence of mental disorders, including psychosis.

An Early Developmental Marker of Deficit versus Nondeficit Schizophrenia

People with schizophrenia and primary negative symptoms (deficit schizophrenia) differ from those without such symptoms (nondeficit schizophrenia) on risk factors, course of illness, other signs and symptoms, treatment response, and biological correlates. These differences suggest that the 2 groups may also have developmental differences. A previous study found that people with schizophrenia have a wider palate than comparison subjects. We tested the hypothesis that those with deficit and nondeficit schizophrenia would differ on palate width. A dentist made blinded measurements of palate shape in deficit (N = 21) and nondeficit (N = 25) patients and control subjects (N = 127), matched for age and gender. The deficit group had significantly wider palates than either nondeficit or control subjects (respective means [standard deviation] 37.5 [3.9], 33.7 [3.1], and 34.0 [2.9]; P < .001 for both deficit/nondeficit and deficit/control comparisons, respective effect sizes 1.08 and 1.01). The nondeficit/control difference in width was not significant (P = .83), and there were no significant group differences in length or depth. The power to detect a nondeficit/control difference in width equal in size to that of the deficit/control difference in width (3.5 mm) was 0.99 and 0.92 for a 2.0-mm difference. This difference in palate width may reflect a divergence in development between deficit and nondeficit patients that occurs by the early second trimester and is consistent with the hypothesis that deficit schizophrenia is a separate disease within the syndrome of schizophrenia.

Assessment of cognitive impairment in HSV-1 positive schizophrenia and bipolar patients: Systematic review and meta-analysis

A common characteristic among schizophrenia and bipolar disorder patients is cognitive dysfunction, especially for memory and attention. Recent evidence has suggested that cognitive impairment in schizophrenia and bipolar disorder patients could be associated with herpes simplex virus 1 (HSV-1) infection, due to the ability of HSV-1 to infect neurons in the temporal lobe, which plays a key role in the formation of memory and processing of sensory input. The objective of this review is to analyze the aggregate neuropsychological testing data from previous studies regarding the impact of HSV-1 infection on cognitive function in schizophrenia and bipolar disorder. A systematic literature search generated a total of 379 articles; 12 full-text case control and cross-sectional studies met the eligibility criteria to be included in the review. Pooled effects assessed the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) total scores and the three index scores for immediate memory, delayed memory, and attention in a random effects model. The overall effect for RBANS total score was in favor of the HSV-1 positive group (z = 3.10, p = 0.002). A statistically significant overall effect of cognitive impairment for memory and attention indices was in favor of HSV positive schizophrenia patients (z = 5.95 p < 0.00001). The findings from the meta-analysis suggest that serological evidence of HSV-1 infection has a significant impact on cognitive function with small to moderate effect sizes (-0.23 to -0.49), particularly affecting memory and attention, in schizophrenia and bipolar patients.

Antibodies in the Diagnosis, Prognosis, and Prediction of Psychotic Disorders

Blood-based biomarker discovery for psychotic disorders has yet to impact upon routine clinical practice. In physical disorders antibodies have established roles as diagnostic, prognostic and predictive (theranostic) biomarkers, particularly in disorders thought to have a substantial autoimmune or infective aetiology. Two approaches to antibody biomarker identification are distinguished: a "top-down" approach, in which antibodies to specific antigens are sought based on the known function of the antigen and its putative role in the disorder, and emerging "bottom-up" or "omics" approaches that are agnostic as to the significance of any one antigen, using high-throughput arrays to identify distinctive components of the antibody repertoire. Here we review the evidence for antibodies (to self-antigens as well as infectious organism and dietary antigens) as biomarkers of diagnosis, prognosis, and treatment response in psychotic disorders. Neuronal autoantibodies have current, and increasing, clinical utility in the diagnosis of organic or atypical psychosis syndromes. Antibodies to selected infectious agents show some promise in predicting cognitive impairment and possibly other symptom domains (eg, suicidality) within psychotic disorders. Finally, infectious antibodies and neuronal and other autoantibodies have recently emerged as potential biomarkers of response to anti-infective therapies, immunotherapies, or other novel therapeutic strategies in psychotic disorders, and have a clear role in stratifying patients for future clinical trials. As in nonpsychiatric disorders, combining biomarkers and large-scale use of "bottom-up" approaches to biomarker identification are likely to maximize the eventual clinical utility of antibody biomarkers in psychotic disorders.

Reduced willingness to invest effort in schizophrenia with high negative symptoms regardless of reward stimulus presentation and reward value

BACKGROUND

Negative symptoms in schizophrenia, which are related to poor functioning, are thought to be grounded on aberrant functioning in the reward system. We aimed to disentangle how negative symptoms and two cognitive aspects of goal-directed behavior, mental representation of reward and reward value, affect willingness to invest effort to attain a reward in schizophrenia.

AIMS AND PROCEDURES

To this purpose, 43 schizophrenia patients and 35 healthy controls were assessed for negative symptoms and general functioning, and completed an effort-based reward task. Patients were split in high and low negative symptoms scorers. A series of ANOVA tests were conducted in order to test the effects of group controlling for representation of reward (Task 1) and balance between reward value and effort (Task 2) on will to invest effort to attain a reward.

MAIN FINDINGS

Schizophrenia patients with high negative symptoms chose to invest lower amounts of effort for a reward compared both to low negative symptoms patients and to controls in both tasks. Neither mental representation of reward (Task 1) nor reward value (Task 2) did differentially affect will to invest effort between-groups.

CONCLUSIONS

These findings suggest that the lower willingness to invest effort observed in schizophrenia patients with high negative symptoms may not be related to cognitive aspects of goal-oriented behavior.

Exploring the associations of herpes simplex virus infection and cognitive dysfunction in schizophrenia: Studies in India

BACKGROUND

Cognitive dysfunctions being core features of schizophrenia (SZ), cause disability, increase burden and are refractory to treatment. Viral infections are not risk factors for SZ, but growing evidence indicates infection with some neurotropic viruses, particularly Herpes simplex virus type 1 (HSV -1) as a risk factor for cognitive dysfunction.

STUDIES IN INDIA

Three research studies in India are described. In the first, participants were evaluated for HSV-1 infection and cognitive functions (cases 198 and controls 100). In the second, patients and normal nonpsychotic control individuals were examined at baseline and followed up over 1-3 years (cases 138 and controls 88). In the third, a randomized, double-blind placebo-controlled antipsychotic adjunctive trial was conducted to examine the effect of anti-viral drug valacyclovir over 16 weeks on cognitive functioning (valacyclovir 30; placebo 32, treatment for 16 weeks).

RESULTS OF INDIAN STUDIES

Cross-sectional study: HSV-1 infection was associated with modest dysfunction, especially on attention (accuracy) and spatial processing (speed).

LONGITUDINAL STUDY

HSV-1 seropositive participants had lower scores at baseline on 6/16 measures, regardless of SZ diagnoses. At follow-up, there was a significant decline in HSV-1-positive participants for abstraction and mental flexibility and emotion discrimination.

RANDOMIZED CONTROLLED TRIAL

Significantly, greater improvement in accuracy index of emotion discrimination in the valacyclovir-treated versus placebo sample was found.

CONCLUSIONS

Indian studies are consistent with a causative role for HSV-1 in cognitive dysfunction regardless of SZ diagnosis; more rigorous studies of the causal hypothesis are needed, particularly larger randomized controlled trials.

A prenatal interruption of DISC1 function in the brain exhibits a lasting impact on adult behaviors, brain metabolism, and interneuron development

Mental illnesses like schizophrenia (SCZ) and major depression disorder (MDD) are devastating brain disorders. The SCZ risk gene, disrupted in schizophrenia 1 (DISC1), has been associated with neuropsychiatric conditions. However, little is known regarding the long-lasting impacts on brain metabolism and behavioral outcomes from genetic insults on fetal NPCs during early life. We have established a new mouse model that specifically interrupts DISC1 functions in NPCs in vivo by a dominant-negative DISC1 (DN-DISC1) with a precise temporal and spatial regulation. Interestingly, prenatal interruption of mouse Disc1 function in NPCs leads to abnormal depression-like deficit in adult mice. Here we took a novel unbiased metabonomics approach to identify brain-specific metabolites that are significantly changed in DN-DISC1 mice. Surprisingly, the inhibitory neurotransmitter, GABA, is augmented. Consistently, parvalbumin (PV) interneurons are increased in the cingulate cortex, retrosplenial granular cortex, and motor cortex. Interestingly, somatostatin (SST) positive and neuropeptide Y (NPY) interneurons are decreased in some brain regions, suggesting that DN-DISC1 expression affects the localization of interneuron subtypes. To further explore the cellular mechanisms that cause this change, DN-DISC1 suppresses proliferation and promotes the cell cycle exit of progenitors in the medial ganglionic eminence (MGE), whereas it stimulates ectopic proliferation of neighboring cells through cell non-autonomous effect. Mechanistically, it modulates GSK3 activity and interrupts Dlx2 activity in the Wnt activation. In sum, our results provide evidence that specific genetic insults on NSCs at a short period of time could lead to prolonged changes of brain metabolism and development, eventually behavioral defects.

Neuropsychological Profile of Specific Executive Dysfunctions in Patients with Deficit and Non-deficit Schizophrenia

Objectives: Although it has been shown that there are more profound deficits present in deficit schizophrenia (DS) patients than in non-deficit schizophrenia (NDS) patients, there still remain some matters requiring further investigation. In this context, we formulated three research aims: (1) to compare executive functions between the investigated groups, (2) to determine the relationship between particular aspects of executive functions within the groups, and (3) to draw up a neuropsychological profile for executive functions.

Methods: The study involved 148 schizophrenia patients divided into two groups on the basis of the Schedule for the Deficit Syndrome: DS (n = 70) and NDS (n = 78). Patients were matched for sex, age, years of education, and overall cognitive functioning. For assessing executive functions we used the Wisconsin Card Sorting Test (WCST), the Trail Making Test (TMT), the Phonemic Verbal Fluency Test (VFT P), the Stroop Color and Word Test (SCWT), and the Go/No Go task (GNG).

Results: Deficit schizophrenia patients scored lower on the WCST and TMT (relative flexibility) than did the NDS patients. There were no inter-group differences in the VFT P, SCWT (relative inhibition), or GNG. There were significant correlations between WCST and TMT scores in both groups. The general neuropsychological profiles were similar in both groups.

Conclusion: Deficit schizophrenia patients exhibited slightly greater interference with concept formation and non-verbal cognitive flexibility. Therefore, such problems may be specific to this particular type of schizophrenia. These results may be useful for the development of neuropsychological diagnostic methods for patients with schizophrenia.

Primary and persistent negative symptoms: Concepts, assessments and neurobiological bases

Primary and persistent negative symptoms (PPNS) represent an unmet need in the care of people with schizophrenia. They have an unfavourable impact on real-life functioning and do not respond to available treatments. Underlying etiopathogenetic mechanisms of PPNS are still unknown. The presence of primary and enduring negative symptoms characterizes deficit schizophrenia (DS), proposed as a separate disease entity with respect to non-deficit schizophrenia (NDS). More recently, to reduce the heterogeneity of negative symptoms by using criteria easily applicable in the context of clinical trials, the concept of persistent negative symptoms (PNS) was developed. Both PNS and DS constructs include enduring negative symptoms (at least 6months for PNS and 12months for DS) that do not respond to available treatments. PNS exclude secondary negative symptoms based on a cross-sectional evaluation of severity thresholds on commonly used rating scales for positive symptoms, depression and extrapyramidal side effects; the DS diagnosis, instead, excludes all potential sources of secondary negative symptoms based on a clinical longitudinal assessment. In this paper we review the evolution of concepts and assessment modalities relevant to PPNS, data on prevalence of DS and PNS, as well as studies on clinical, neuropsychological, brain imaging electrophysiological and psychosocial functioning aspects of DS and PNS.

Neurocognitive impairment in the deficit subtype of schizophrenia

Schizophrenia is a heterogeneous disorder characterized by numerous diverse signs and symptoms. Individuals with prominent, persistent, and idiopathic negative symptoms are thought to encompass a distinct subtype of schizophrenia. Previous work, including studies involving neuropsychological evaluations, has supported this position. The present study sought to further examine whether deficit patients are cognitively distinct from non-deficit patients with schizophrenia. A comprehensive neurocognitive battery including tests of verbal memory, vigilance, processing speed, reasoning, and working memory was administered to 657 patients with schizophrenia. Of these, 144 (22 %) patients were classified as deficit patients using a proxy identification method based on severity, persistence over time, and possible secondary sources (e.g., depression) of negative symptoms. Deficit patients with schizophrenia performed worse on all tests of cognition relative to non-deficit patients. These patients were characterized by a generalized cognitive impairment on the order of about 0.4 standard deviations below that of non-deficit patients. However, when comparing deficit patients to non-deficit patients who also present with negative symptoms, albeit not enduring or primary, no group differences in cognitive performance were found. Furthermore, a discriminant function analysis classifying patients into deficit/non-deficit groups based on cognitive scores demonstrated only 62.3 % accuracy, meaning over one-third of individuals were misclassified. The deficit subtype of schizophrenia is not markedly distinct from non-deficit schizophrenia in terms of neurocognitive performance. While deficit patients tend to have poorer performance on cognitive tests, the magnitude of this effect is relatively modest, translating to over 70 % overlap in scores between groups.

Are Negative Symptoms Dimensional or Categorical? Detection and Validation of Deficit Schizophrenia With Taxometric and Latent Variable Mixture Models

Studies have supported the validity of the deficit form of schizophrenia (ie, people with primary and enduring negative symptoms). A test of whether that group is a true taxon-that is, a distinct, discontinuous group-has yet to be conducted and the underlying structure of negative symptoms as categorical or dimensional remains undetermined. The present study examined the latent structure of negative and deficit symptoms to determine if a nonarbitrary boundary distinguishes deficit from nondeficit forms of schizophrenia (ie, whether these symptoms reflect a continuous or categorical variable). Schedule for the Deficit Syndrome ratings of 789 individuals with a psychotic disorder were submitted to taxometric and latent variable mixture analyses to test categorical vs dimensional hypotheses of negative symptoms and deficit schizophrenia. Analytic models favored a taxonic structure of negative symptoms and the validity of the deficit/nondeficit classification scheme. Taxometric classification outperformed clinician-based deficit/nondeficit classification in its association with summer birth, male sex, premorbid adjustment, neurocognition, and psychosocial functioning. Within taxon and complement classes, severity scores remained significant predictors of premorbid adjustment, neurocognition, and psychosocial functioning. Thus, although a categorical approach is validated, a hybrid categorical-dimensional conceptualization of negative symptoms also has validity for the prediction of external variables.

Neurocognitive functioning of individuals with schizophrenia: using and not using drugs

OBJECTIVES

Research on neurocognition in schizophrenia, using modest samples and self-rated assessments, reports drug use contributes to improved rather than impaired cognitive function. We have sought to replicate these findings in a large sample of patients that had their drug-use status confirmed by laboratory assays and evaluated the potential differences in cognitive function between patients with positive and negative results.

METHODS

Nine hundred and seventy four schizophrenia patients completed neuropsychological and laboratory tests at screening/baseline of the Clinical Antipsychotic Trials of Intervention Effectiveness study. Radioimmunoassay (RIA) of hair tested for cannabis, cocaine and methamphetamine.

RESULTS

Many patients screened positive for drug use (n = 262; 27%), and there were no differences between patients with positive and negative results in terms of cognitive function after adjusting for multiple inference testing, except patients with positive RIA for methamphetamine demonstrated increased processing speed (corrected, P = .024). Moderator models were employed to explore potential subgroup differences in this pattern of results. At low medication dosages, patients with positive RIA for cocaine demonstrated decreased processing speed compared with patients with negative RIA for cocaine (uncorrected, P = .008). And for any other drugs with low psychopathology, patients with positive RIA demonstrated decreased working memory compared with patients with negative RIA (uncorrected, P = .006).

CONCLUSIONS

No positive effects of cannabis on cognitive function were observed, and drug use was not associated with improved neurocognition across most of the subgroup characteristics explored in this sample of schizophrenia patients.

High prevalence of Human Herpesvirus 8 in schizophrenic patients

Many studies have reported an association between Herpes family viruses and an increased risk of schizophrenia, but the role of Human Herpesvirus 8 (HHV8) has never been investigated. This study aimed to assess HHV8 prevalence in schizophrenic patients as well as the possible association between HHV8 infection and schizophrenia clinical features. We consecutively enrolled 108 patients meeting fourth edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria of schizophrenia and 108 age and sex matched controls. Data about a number of demographic characteristics and potential HHV8 risk factors of infection were collected. Standardized psychopathology measures, disease severity and functioning level were obtained using Positive and Negative Syndrome Scale (PANSS), Brief Psychiatric Rating Scale (BPRS), Scale for the Assessment of Negative Symptoms (SANS), Scale for the Assessment of Positive Symptoms (SAPS), Clinical Global Impressions (CGI) and Global Assessment of functioning (GAF). The presence of anti-HHV8 antibodies was analyzed using an indirect immunofluorescence assay. A higher prevalence of HHV8 infection in schizophrenic patients than in controls was found. Marital status, having children, sexual behavior and risk factors of blood transmission were not associated with HHV8 prevalence. However, among schizophrenic patients, HHV8 prevalence was statically associated with positive symptoms. To our knowledge, this would be the first report of a possible role of HHV8 in the pathogenesis of schizophrenia. To prove this hypothesis, further investigation of HHV8 in schizophrenia with larger samples is needed.

Progress in the study of negative symptoms

A selective review of the negative symptoms of schizophrenia is an appropriate article to result from the festschrift honoring William T. Carpenter Jr, as he has made substantial contributions in this area. This review assesses progress in 3 areas in which he has been an important investigator: the distinction between primary vs secondary negative symptoms; the appropriate design for treatment trials; and the nosology of negative symptoms.

Cytomegalovirus seropositivity and serointensity are associated with hippocampal volume and verbal memory in schizophrenia and bipolar disorder

INTRODUCTION

Cytomegalovirus (CMV) is a member of the herpesviridae family that has a limbic and temporal gray matter tropism. It is usually latent in humans but has been associated with schizophrenia, bipolar disorder and cognitive deficits in some populations. Hippocampal decreased volume and dysfunction play a critical role in these cognitive deficits. We hypothesized that CMV seropositivity and serointensity would be associated with hippocampal volume and cognitive functioning in patients with schizophrenia or bipolar disorder.

METHODS

102 healthy controls, 118 patients with bipolar disorder and 69 patients with schizophrenia performed the California Verbal Learning Test (CVLT) and had blood samples drawn to assess CMV IgG levels. A subgroup of 52 healthy controls, 31 patients with bipolar disorder and 27 patients with schizophrenia underwent T1 MRI for hippocampal volumetry. We analyzed the association between CMV serointensity and seropositivity with hippocampal volume. We also explored the correlation between CMV serointensity and seropositivity and CVLT scores.

RESULTS

In both patient groups but not in controls, higher CMV serointensity was significantly associated with smaller right hippocampal volume. Further, in the group of patients with schizophrenia but not bipolar disorder, CMV serointensity was negatively correlated with CVLT scores.

CONCLUSION

CMV IgG titers are associated with decreased hippocampal volume and poorer episodic verbal memory in patients with schizophrenia or bipolar disorder. The mechanism of this association warrants further exploration.

Viral infection, inflammation and schizophrenia

Schizophrenia is a severe neurodevelopmental disorder with genetic and environmental etiologies. Prenatal viral/bacterial infections and inflammation play major roles in the genesis of schizophrenia. In this review, we describe a viral model of schizophrenia tested in mice whereby the offspring of mice prenatally infected with influenza at E7, E9, E16, and E18 show significant gene, protein, and brain structural abnormalities postnatally. Similarly, we describe data on rodents exposed to bacterial infection or injected with a synthetic viral mimic (PolyI:C) also demonstrating brain structural and behavioral abnormalities. Moreover, human serologic data has been indispensible in supporting the viral theory of schizophrenia. Individuals born seropositive for bacterial and viral agents are at a significantly elevated risk of developing schizophrenia. While the specific mechanisms of prenatal viral/bacterial infections and brain disorder are unclear, recent findings suggest that the maternal inflammatory response may be associated with fetal brain injury. Preventive and therapeutic treatment options are also proposed. This review presents data related to epidemiology, human serology, and experimental animal models which support the viral model of schizophrenia.

Human endogenous retrovirus type W (HERV-W) in schizophrenia: a new avenue of research at the gene-environment interface

OBJECTIVES

Provide a synthetic review of recent studies evidencing an association between human endogenous retrovirus-W (HERV-W) and schizophrenia.

METHODS

Bibliography analysis and contextual synthesis.

RESULTS

Epidemiological studies suggest that the aetiology of schizophrenia is complex and involves a complex interplay of genetic and environmental factors such as infections. Eight percentof the human genome consists of human endogenous retroviruses (HERV), and this part of the genome was previously thought to be without importance, but new research has refuted this. HERVs share similarities with viruses and it is assumed that HERVs are present in the genome as a result of retroviruses infecting germ line cells many million years ago. A specific type of HERVs, called HERV-W, has through several recent studies been associated with schizophrenia. Elevated transcription of HERV-W elements has been documented, and antigens of HERV-W envelope and capsid proteins have been found in blood samples from patients. Viruses that have been implicated in pathology of schizophrenia, such as herpes and influenza, have been shown to activate HERV-W elements, and such activation has been associated with elevated biomarkers of systemic inflammation. New research indicates that HERV-W may be an important genetic factor interplaying with the environmental risk factor of infections and that, through this, HERV-W may be important for disease pathogenesis.

CONCLUSIONS

A lifelong scenario of a detrimental interaction between infectious agents and HERV-W genes may decipher the actual development and course of schizophrenia. Further research is needed to find out if specific treatment strategies could reduce the expression of HERV-W and if this will be associated with remission.

Inflammatory markers in antipsychotic-naïve patients with nonaffective psychosis and deficit vs. nondeficit features

Newly diagnosed, antipsychotic-naïve patients with nonaffective psychosis appear to have increases in pro-inflammatory cytokines. Patients characterized by primary, enduring negative symptoms (deficit symptoms) differ from patients without such features with regard to course of illness, treatment response, risk factors and metabolic disturbances. We hypothesized that they would also differ on concentrations of the inflammatory markers interleukin-6 (IL6) and C-reactive protein (CRP). Newly diagnosed, antipsychotic-naïve patients with nonaffective psychosis were categorized into deficit (N=20) and nondeficit (N=42) groups, and were matched on age, gender, body mass index, smoking, cortisol level, socioeconomic status, and the severity of psychotic symptoms. Fasting concentrations of IL6 were significantly higher in deficit (mean [S.D.]) (8.0 pg/ml [12.7]) than nondeficit patients (0.3 pg/ml [1.3]). CRP levels were also significantly higher in the deficit patients (0.3 mg/dl [0.4]) vs. (0.2 mg/dl [0.4]), respectively. In contrast, 2-h glucose concentrations (2HG) in a glucose tolerance test were lower in the deficit than the nondeficit group. Our results show a double dissociation with regard to glucose intolerance and inflammation: the deficit group has greater inflammation, but less severe glucose intolerance. These results provide further evidence for the validity of the deficit/nondeficit categorization.

Tardive dyskinesia and deficit schizophrenia

OBJECTIVE

Despite comparable antipsychotic exposure, some patients experience involuntary movements yet others do not. Negative symptoms have been associated with tardive dyskinesia (TD), but it is not certain whether this is an association with primary negative symptoms or the effects of medications. The aim of the present study was to determine whether patients with deficit schizophrenia (who have primary negative symptoms) are more likely to experience TD than those with non-deficit schizophrenia.

METHOD

In 2006, all the people with a clinical diagnosis of schizophrenia in Nithsdale, Southwest Scotland, were identified using the 'key informant' method. These patients were categorized into those with and without the deficit syndrome and assessed for the presence of TD. Patients were also assessed for akathisia and extrapyramidal side effects.

RESULTS

Of the 131 people assessed, 31 were categorized as having deficit schizophrenia (23.7%) and 100 people (76.3%) as non-deficit. There was no difference between the two groups with regard to age, antipsychotic exposure, and duration of illness. There was a significant association between deficit features and TD with an odds ratio = 2.97 [95% CI 1.128-6.88, P = 0.009].

CONCLUSION

Our findings support the proposal that the pathological process underlying deficit schizophrenia can predispose to the development of TD.

The brief negative symptom scale: psychometric properties

The participants in the NIMH-MATRICS Consensus Development Conference on Negative Symptoms recommended that an instrument be developed that measured blunted affect, alogia, asociality, anhedonia, and avolition. The Brief Negative Symptom Scale (BNSS) is a 13-item instrument designed for clinical trials and other studies that measures these 5 domains. The interrater, test-retest, and internal consistency of the instrument were strong, with respective intraclass correlation coefficients of 0.93 for the BNSS total score and values of 0.89-0.95 for individual subscales. Comparisons with positive symptoms and other negative symptom instruments supported the discriminant and concurrent validity of the instrument.

The environment and susceptibility to schizophrenia

In the present article the putative role of environmental factors in schizophrenia is reviewed and synthesized. Accumulating evidence from recent studies suggests that environmental exposures may play a more significant role in the etiopathogenesis of this disorder than previously thought. This expanding knowledge base is largely a consequence of refinements in the methodology of epidemiologic studies, including birth cohort investigations, and in preclinical research that has been inspired by the evolving literature on animal models of environmental exposures. This paper is divided into four sections. In the first, the descriptive epidemiology of schizophrenia is reviewed. This includes general studies on incidence, prevalence, and differences in these measures by urban-rural, neighborhood, migrant, and season of birth status, as well as time trends. In the second section, we discuss the contribution of environmental risk factors acting during fetal and perinatal life; these include infections [e.g. rubella, influenza, Toxoplasma gondii (T. gondii), herpes simplex virus type 2 (HSV-2)], nutritional deficiencies (e.g., famine, folic acid, iron, vitamin D), paternal age, fetal/neonatal hypoxic and other obstetric insults and complications, maternal stress and other exposures [e.g. lead, rhesus (Rh) incompatibility, maternal stress]. Other putative neurodevelopmental determinants, including cannabis, socioeconomic status, trauma, and infections during childhood and adolescence are also covered. In the third section, these findings are synthesized and their implications for prevention and uncovering biological mechanisms, including oxidative stress, apoptosis, and inflammation, are discussed. Animal models, including maternal immune activation, have yielded evidence suggesting that these exposures cause brain and behavioral phenotypes that are analogous to findings observed in patients with schizophrenia. In the final section, future studies including new, larger, and more rigorous epidemiologic investigations, and research on translational and clinical neuroscience, gene-environment interactions, epigenetics, developmental trajectories and windows of vulnerability, are elaborated upon. These studies are aimed at confirming observed risk factors, identifying new environmental exposures, elucidating developmental mechanisms, and shedding further light on genes and exposures that may not be identified in the absence of these integrated approaches. The study of environmental factors in schizophrenia may have important implications for the identification of causes and prevention of this disorder, and offers the potential to complement, and refine, existing efforts on explanatory neurodevelopmental models.

The human endogenous retrovirus link between genes and environment in multiple sclerosis and in multifactorial diseases associating neuroinflammation

Endogenous retroviruses represent about 8% of the human genome and belong to the superfamily of transposable and retrotransposable genetic elements. Altogether, these mobile genetic elements and their numerous inactivated "junk" sequences represent nearly one half of the human DNA. Nonetheless, a significant part of this "non-conventional" genome has retained potential activity. Epigenetic control is notably involved in silencing most of these genetic elements but certain environmental factors such as viruses are known to dysregulate their expression in susceptible cells. More particularly, embryonal cells with limited gene methylation are most susceptible to uncontrolled activation of these mobile genetic elements by, e.g., viral infections. In particular, certain viruses transactivate promoters from endogenous retroviral family type W (HERV-W). HERV-W RNA was first isolated in circulating viral particles (Multiple Sclerosis-associated RetroViral element, MSRV) that have been associated with the evolution and prognosis of multiple sclerosis. HERV-W elements encode a powerful immunopathogenic envelope protein (ENV) that activates a pro-inflammatory and autoimmune cascade through interaction with Toll-like receptor 4 on immune cells. This ENV protein has repeatedly been detected in MS brain lesions and may be involved in other diseases. Epigenetic factors controlling HERV-W ENV protein expression then reveal critical. This review addresses the gene-environment epigenetic interface of such HERV-W elements and its potential involvement in disease.

Trimethoprim as adjuvant treatment in schizophrenia: a double-blind, randomized, placebo-controlled clinical trial

Various infectious agents, such as Toxoplasma gondii, have been hypothesized to be potentially relevant etiological factors in the onset of some cases of schizophrenia. We conducted a randomized, double-blind, placebo-controlled treatment trial in an attempt to explore the hypothesis that the symptoms of schizophrenia may be related to infection of the central nervous system with toxoplasma gondii. Systematically selected patients with ongoing and at least moderately severe schizophrenia from Butajira, in rural Ethiopia, were randomly allocated to trimethoprim or placebo, which were added on to participants' regular antipsychotic treatments. Trial treatments were given for 6 months. The Positive and Negative Syndrome Scale (PANSS) was used to assess outcome. Ninety-one patients were included in the study, with 80 cases (87.9%) positive for T. gondii immunoglobulin G antibody. Seventy-nine subjects (87.0%) completed the trial. The mean age of subjects was 35.3 (SD = 8.0) years, with a mean duration of illness of 13.2 (SD = 6.7) years. Both treatment groups showed significant reduction in the overall PANSS score with no significant between-group difference. In this sample of patients with chronic schizophrenia, trimethoprim used as adjuvant treatment is not superior to placebo. However, it is not possible to draw firm conclusion regarding the etiological role of toxoplasmosis on schizophrenia based on this study because the timing and the postulated mechanisms through which toxoplasmosis produces schizophrenia are variable.

Animal models of virus-induced neurobehavioral sequelae: recent advances, methodological issues, and future prospects

Converging lines of clinical and epidemiological evidence suggest that viral infections in early developmental stages may be a causal factor in neuropsychiatric disorders such as schizophrenia, bipolar disorder, and autism-spectrum disorders. This etiological link, however, remains controversial in view of the lack of consistent and reproducible associations between viruses and mental illness. Animal models of virus-induced neurobehavioral disturbances afford powerful tools to test etiological hypotheses and explore pathophysiological mechanisms. Prenatal or neonatal inoculations of neurotropic agents (such as herpes-, influenza-, and retroviruses) in rodents result in a broad spectrum of long-term alterations reminiscent of psychiatric abnormalities. Nevertheless, the complexity of these sequelae often poses methodological and interpretational challenges and thwarts their characterization. The recent conceptual advancements in psychiatric nosology and behavioral science may help determine new heuristic criteria to enhance the translational value of these models. A particularly critical issue is the identification of intermediate phenotypes, defined as quantifiable factors representing single neurochemical, neuropsychological, or neuroanatomical aspects of a diagnostic category. In this paper, we examine how the employment of these novel concepts may lead to new methodological refinements in the study of virus-induced neurobehavioral sequelae through animal models.

Negative symptoms and concomitant attention deficits in schizophrenia: associations with prospective assessments of anxiety, social dysfunction, and avoidant coping

BACKGROUND

Negative symptoms are a significant barrier to function and may have a range of etiological roots and links to outcome. A previous study identified a subgroup of patients with schizophrenia who had both higher levels of negative symptoms and relatively poorer attentional function who had uniquely lower self-esteem and greater internalized stigma.

AIMS

To determine whether participants previously classified as having High Negative/Poorer Attention would continue to have lower self-esteem, higher self-stigma, and also higher levels of anxiety and avoidant coping 5 months later.

METHOD

Participants were 77 (77.8%) of the original 99 participants who completed follow-up procedures.

RESULTS

The High Negative/Poorer Attention group had significantly poorer social functioning, lower appraisal of their competence, higher levels of anxiety, and a higher preference for ignoring stressors five months after classification.

CONCLUSIONS

Negative symptoms with concomitant attention deficits may lead to more social and psychological dysfunction than negative symptoms or attention deficits alone. Individuals with both high levels of negative symptoms and poor attention may represent a meaningful subgroup with unique psychosocial difficulties that persist over time.

Clinical perspectives on autoimmune processes in schizophrenia

This article reviews the epidemiology of autoimmune conditions in schizophrenia, symptom manifestations of autoimmune conditions resembling schizophrenia, and the immunological changes observed in schizophrenia; and reflects on their associations with neurodevelopment, neurodegeneration, clinical course, and management of schizophrenia.

Deficit schizophrenia: an overview of clinical, biological and treatment aspects

The concept of deficit schizophrenia is regarded as one of the most promising attempts to reduce heterogeneity within schizophrenia. This paper summarizes the clinical, neurocognitive, brain imaging and electrophysiological correlates of this subtype of schizophrenia. Attempts to identify genetic and non-genetic risk factors are reviewed. Methodological limitations of studies supporting the efficacy of atypical antipsychotics in the treatment of the syndrome are highlighted. Two decades of research on deficit schizophrenia have failed to prove that it represents the extreme end of a severity continuum in schizophrenia, while some findings support the claim that it may be a separate disease entity.

Differences in glucose tolerance between deficit and nondeficit schizophrenia

Some studies suggest that schizophrenia is associated with an increased risk of diabetes independently of antipsychotic use. People with deficit schizophrenia, which is characterized by primary (or idiopathic), enduring negative symptoms, differ from those with nondeficit schizophrenia on course of illness, treatment response, risk factors, and biological correlates. We hypothesized that deficit and nondeficit subjects would also differ with regard to glucose tolerance. Newly diagnosed, antipsychotic-naïve subjects with nonaffective psychosis and matched control subjects were administered a 75 g oral glucose tolerance test (GTT). Two-hour glucose concentrations were significantly higher in the nondeficit patients (N=23; mean [SD] of 121.6 [42.0]) than in deficit (N=23; 100.2 [23.1]) and control subjects (N=59; 83.8 [21.9]); the deficit subjects also had significantly higher two-hour glucose concentrations than did the control subjects. These results provide further support that the deficit group has a distinctive etiopathophysiology.

A possible relationship between Toxoplasma gondii and schizophrenia: A seroprevalence study

Objective. Schizophrenia is a pervasive neuropsychiatric disease of uncertain etiology. We aimed to investigate a possible association between Toxoplasma gondii infection and schizophrenia in this study. Method. We selected individuals with schizophrenia (n=88) and tested them with commercially available enzyme-linked immunosorbent assay (ELISA) for anti-Toxoplasma IgG and IgM antibodies and compared these seropositivity rate to those of controls without psychiatric disease (n=88). Results. The rate of IgG antibody in the schizophrenia patients (47.7%) was higher than the control groups (20.4%) (P<0.001). We did not find any anti-Toxoplasma IgM seropositivity in both schizophrenia patients and control group. In schizophrenic patients with and without anti-Toxoplasma IgG groups statistical analysis did not reveal any correlation between demographic variables and Toxoplasma infection. Conclusion. Our findings supported previous studies indicate that T.gondii may play a role in etiopathogenesis in some cases of 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.

Deficit schizophrenia: an update

The criteria for deficit schizophrenia were designed to define a group of patients with enduring, primary (or idiopathic) negative symptoms. In 2001, a review of the literature suggested that deficit schizophrenia constitutes a disease separate from nondeficit forms of schizophrenia. Here we provide a review of new studies, not included in that paper, in which patients with deficit schizophrenia and those with nondeficit schizophrenia were compared on dimensions typically used to distinguish diseases: signs and symptoms, course of illness, pathophysiological correlates, risk and etiological factors, and treatment response. Replicated findings and new evidence of double dissociation supporting the separate disease hypothesis are highlighted. Weaknesses in research and treatment options for these patients are also emphasized.

Schizoid-like features and season of birth in a nonpatient sample

OBJECTIVES

People with the deficit subtype of schizophrenia differs from others with schizophrenia with regard to risk factors, signs and symptoms, biological correlates, treatment response, and course of illness. The deficit group, which is characterized by decreased social interests and a lack of depression, has a well-replicated association with June/July birth, which contrasts with the association of schizophrenia as a whole with winter birth. As some of the correlates of schizophrenia are found in subclinical form in the schizophrenia spectrum, we hypothesized that June/July birth would be associated with the combination of decreased sociality in the absence of depression in a nonpatient group as well.

METHODS

The Beck Depression Inventory and Chapman's Perceptual Aberration, Magical Ideation, and Social Anhedonia scales were administered to university students. The Perceptual Aberration and Magical Ideation scale scores were combined into a single psychotic-like symptom score (PerMag). Blind to month of birth, each subject (N=425) was given a score that quantified the combination of social anhedonia and an absence of depression. Analyses were then performed in subjects in the upper 50% of PerMag scores who had complete data (N=171, 27.5% male).

RESULTS

June/July birth (p=.037) and male gender (p=.002) were both found to be associated with higher scores on the combination of social anhedonia and a low depression score; the interaction of these factors was not significant.

CONCLUSIONS

These results suggest that the same seasonal factor that contributes to the risk of deficit schizophrenia may affect brain development and personality characteristics in the general population.

Are some cases of psychosis caused by microbial agents? A review of the evidence

The infectious theory of psychosis, prominent early in the twentieth century, has recently received renewed scientific support. Evidence has accumulated that schizophrenia and bipolar disorder are complex diseases in which many predisposing genes interact with one or more environmental agents to cause symptoms. The protozoan Toxoplasma gondii and cytomegalovirus are discussed as examples of infectious agents that have been linked to schizophrenia and in which genes and infectious agents interact. Such infections may occur early in life and are thus consistent with neurodevelopmental as well as genetic theories of psychosis. The outstanding questions regarding infectious theories concern timing and causality. Attempts are underway to address the former by examining sera of individuals prior to the onset of illness and to address the latter by using antiinfective medications to treat individuals with psychosis. The identification of infectious agents associated with the etiopathogenesis of schizophrenia might lead to new methods for the diagnosis, treatment and prevention of this disorder.

Schizophrenia: measurements of psychopathology

A key problem in schizophrenia research is how to assess the effects of treatment interventions given the spectrum of schizophrenia symptoms and patients' functioning. Measuring symptoms is complex, because these symptoms cover a wide variety of psychopathologic domains. The commonly recognized domains are the positive, negative, cognitive, excitement, and depression domains. This article critically reviews some of the available assessment tools of these domains together with other associated syndromes. The instruments discussed cover the broad range of psychopathology found in patients who have schizophrenia.

Polymorphisms in MICB are associated with human herpes virus seropositivity and schizophrenia risk

Viral infection may be a risk factor for schizophrenia and has been associated with decreased cognitive functioning in patients. We report associations of SNPs at MICB (MHC class I polypeptide-related sequence B, chromosome 6p21) with cytomegalovirus and herpes simplex virus 1 seropositivity. We previously found associations with schizophrenia on chromosome 6p21 among patients seropositive for cytomegalovirus (CMV) and herpes simplex virus 1 (HSV1). To localize the associations further, we genotyped 26 SNPs spanning 100 kb in a sample of 236 Caucasian schizophrenia patients and 240 controls. Based on suggestive associations, we selected five SNPs at MICB to assay among two additional Caucasian samples that had been serotyped for CMV and HSV1: a case-control sample recruited in Baltimore (n=272 cases, 108 controls), and a case-parent trio sample recruited in Pittsburgh (n=221). Among Baltimore control individuals there were significant associations with antibody status for infectious agents: rs1051788 with HSV1 seropositivity (p=0.006) and rs2523651 with cytomegalovirus seropositivity (p=0.001). The former association was also detectable among the parents of cases recruited in Pittsburgh (p=0.024). Neither viral association was noted among the schizophrenia cases. With respect to schizophrenia risk, significant transmission distortion was noted at rs1051788 and rs1055569 among the case-parent trios regardless of antibody status (p=0.014 and 0.036 respectively). A similar trend for association with schizophrenia liability at rs1051788 in the Baltimore sample did not attain statistical significance. There are a number of explanations for the associations, including chance variation, as well as gene-virus interactions. Further replicate studies are warranted, as are functional studies of these polymorphisms.

Cytomegalovirus and schizophrenia

Several lines of evidence suggest that cytomegalovirus (CMV) may play an aetiological role in schizophrenia. Epidemiologically, both have a worldwide distribution and an increased prevalence in lower socioeconomic groups. Studies have reported that some patients experiencing initial episodes of schizophrenia have increased levels of IgG antibodies against CMV, but not other herpes viruses, in their sera and CSF. Treatment with antipsychotic medications may result in a decrease in CMV antibodies, while treatment with anti-herpes virus and anti-inflammatory medications may reduce symptoms in some individuals with schizophrenia. There is also some overlap in the genes that are thought to operate in CMV infections and schizophrenia. The strongest argument against the role of CMV in schizophrenia is the absence of the traditional CMV neuropathological changes in the brains of individuals with schizophrenia; however, neuropathological studies of CMV have mostly been conducted in immune-compromised individuals. Further studies on CMV and schizophrenia are needed and may lead to improved treatments for schizophrenia.

A classification of sociomedical health indicators: perspectives for health administrators and health planners

The conceptualization and operationalization of measures of health status are considered. Health indicators are conceived as a subset of social indicators, and therefore, as any social indicator, they are viewed as derivative from social issues. The interrelationships of different frames of reference for defining and measuring health that have accompained three distinct health problem patterns in the United States are viewed from a developmental perspective. Mortality and morbidity rates, the traditional health indicators, by themselves no longer serve to assess health status in developed nations. Their deficiencies as indicators serve as background for a classification schema for sociomedical health status indicators that relates health definition frames of reference, measures of health status, and health problems. The role of a group of health indicators-sociomedical heath indicators-in the current formulation of health status measures is assessed.