Risk for obstetric complications and schizophrenia

Gender differences in the association between environment and psychosis

Various environmental exposures have been associated with psychosis spectrum disorder. However, the role of gender in this association has received little attention. Therefore, we conducted a systematic review to evaluate gender-related differences and identified 47 research articles investigating the associations of psychosis with childhood adversity, substance use, urbanicity, migration, season of birth, and obstetric complication in the PubMed database. The findings suggest that childhood abuse may be more strongly associated with a risk to develop psychosis and an earlier age at onset of illness in women than in men. Furthermore, childhood adversity has been associated with the severity of different symptom dimensions in men and women. Growing up in an urban environment and immigration are more strongly associated with psychosis risk in men than in women. Despite a higher prevalence of substance abuse comorbidity in men diagnosed with psychotic disorders, it appears that the association between substance use and psychosis risk may be stronger in women. These findings should be evaluated with caution considering several methodological limitations, limited number of studies, and lack of consistency across results. Overall, although further investigation is needed, our review shows that gender-related differences in the associations of environmental exposures with psychosis expression may exist.

Obstetric complications in women with schizophrenia

Pregnancy, childbirth and motherhood are new situations for women and require adjustment. Women suffering from schizophrenia require special attention due to the course of the disease. Physiological changes that occur in the body during pregnancy may be unacceptable for women suffering from schizophrenia. They may delusively deny the existence of the pregnancy, lead an unhealthy lifestyle (stimulants, poor diet, lack of gynaecological check-ups), which in turn causes an increased risk of complications. In the research conducted so far, it has been proven that three kinds of complications are associated with schizophrenia: complications concerning pregnancy itself (bleeding, diabetes, Rh-incompatibility, pre-eclampsia), intrauterine growth restriction (low birth weight, congenital malformations, small head circumference) and complications regarding labour (uterine atony, asphyxia, emergency Caesarean section). The course of the labour itself in this specific group of patients has not yet been sufficiently examined. It has also been proven that perinatal complications are one of the factors determining an increased risk of schizophrenia.

Maternal Diabetes and Fetal Programming Toward Neurological Diseases: Beyond Neural Tube Defects

The purpose of this review was to search for experimental or clinical evidence on the effect of hyperglycemia in fetal programming to neurological diseases, excluding evident neural tube defects. The lack of timely diagnosis and the inadequate control of diabetes during pregnancy have been related with postnatal obesity, low intellectual and verbal coefficients, language and motor deficits, attention deficit with hyperactivity, problems in psychosocial development, and an increased predisposition to autism and schizophrenia. It has been proposed that several childhood or adulthood diseases have their origin during fetal development through a phenomenon called fetal programming. However, not all the relationships between the outcomes mentioned above and diabetes during gestation are clear, well-studied, or have been related to fetal programming. To understand this relationship, it is imperative to understand how developmental processes take place in health, in order to understand how the functional cytoarchitecture of the central nervous system takes place; to identify changes prompted by hyperglycemia, and to correlate them with the above postnatal impaired functions. Although changes in the establishment of patterns during central nervous system fetal development are related to a wide variety of neurological pathologies, the mechanism by which several maternal conditions promote fetal alterations that contribute to impaired neural development with postnatal consequences are not clear. Animal models have been extremely useful in studying the effect of maternal pathologies on embryo and fetal development, since obtaining central nervous system tissue in humans with normal appearance during fetal development is an important limitation. This review explores the state of the art on this topic, to help establish the way forward in the study of fetal programming under hyperglycemia and its impact on neurological and psychiatric disorders.

Immune responses in perinatal brain injury

The perinatal period has often been described as immune deficient. However, it has become clear that immune responses in the neonate following exposure to microbes or as a result of tissue injury may be substantial and play a role in perinatal brain injury. In this article we will review the immune cell composition under normal physiological conditions in the perinatal period, both in the human and rodent. We will summarize evidence of the inflammatory responses to stimuli and discuss how neonatal immune activation, both in the central nervous system and in the periphery, may contribute to perinatal hypoxic-ischemic brain injury.

Unraveling the genetic architecture of copy number variants associated with schizophrenia and other neuropsychiatric disorders

Recent studies show that the complex genetic architecture of schizophrenia (SZ) is driven in part by polygenic components, or the cumulative effect of variants of small effect in many genes, as well as rare single-locus variants with large effect sizes. Here we discuss genetic aberrations known as copy number variants (CNVs), which fall in the latter category and are associated with a high risk for SZ and other neuropsychiatric disorders. We briefly review recurrent CNVs associated with SZ, and then highlight one CNV in particular, a recurrent 1.6-Mb deletion on chromosome 3q29, which is estimated to confer a 40-fold increased risk for SZ. Additionally, we describe the use of genetic mouse models, behavioral tools, and patient-derived induced pluripotent stem cells as a means to study CNVs in the hope of gaining mechanistic insight into their respective disorders. Taken together, the genomic data connecting CNVs with a multitude of human neuropsychiatric disease, our current technical ability to model such chromosomal anomalies in mouse, and the existence of precise behavioral measures of endophenotypes argue that the time is ripe for systematic dissection of the genetic mechanisms underlying such disease. © 2016 Wiley Periodicals, Inc.

Are obstetrical complications really involved in the etiology and course of schizophrenia and mood disorders?

The impact of stressful experiences during gestation or early life, leading to increased psychiatric disorders susceptibility, is currently well described in literature, however, few data are available on the association between obstetrical complications and later development of specific diagnoses or clinical features (e.g. psychotic symptoms). Aim of the present paper was to evaluate obstetrical complications frequency in different psychiatric diagnoses and their association with clinical features. Three hundred and eighty-eight patients with a diagnosis of schizophrenia, bipolar disorder or major depressive disorder were compared in terms of clinical presentation according to the presence, type and severity of obstetrical complications. Seventeen percent of the total sample (N=65) had history of at least one obstetrical complication. Patients with a history of at least one obstetrical complication result in an earlier age of onset (F=3.93, p=0.04) and a current higher GAF score (F=6.46, p=0.01). Lewis-Murray scale score was directly correlated with GAF scores (t=2.9, p=0.004) and inversely correlated with age at onset (t=-2.77, p=0.006). Obstetrical complications are frequently registered in patients with schizophrenia or mood disorders. In our sample, they appear to have an anticipatory effect on illness onset, but they seem not to be associated with a specific psychiatric diagnosis.

Common or distinct pathways to psychosis? A systematic review of evidence from prospective studies for developmental risk factors and antecedents of the schizophrenia spectrum disorders and affective psychoses

BACKGROUND

Identifying the unique and shared premorbid indicators of risk for the schizophrenia spectrum disorders (SSD) and affective psychoses (AP) may refine aetiological hypotheses and inform the delivery of universal versus targeted preventive interventions. This systematic review synthesises the available evidence concerning developmental risk factors and antecedents of SSD and AP to identify those with the most robust support, and to highlight remaining evidence gaps.

METHODS

A systematic search of prospective birth, population, high-risk, and case-control cohorts was conducted in Medline and supplemented by hand searching, incorporating published studies in English with full text available. Inclusion/exclusion decisions and data extraction were completed in duplicate. Exposures included three categories of risk factors and four categories of antecedents, with case and comparison groups defined by adult psychiatric diagnosis. Effect sizes and prevalence rates were extracted, where available, and the strength of evidence synthesised and evaluated qualitatively across the study designs.

RESULTS

Of 1775 studies identified by the search, 127 provided data to the review. Individuals who develop SSD experience a diversity of subtle premorbid developmental deficits and risk exposures, spanning the prenatal period through early adolescence. Those of greatest magnitude (or observed most consistently) included obstetric complications, maternal illness during pregnancy (especially infections), other maternal physical factors, negative family emotional environment, psychopathology and psychotic symptoms, and cognitive and motor dysfunctions. Relatively less evidence has accumulated to implicate this diversity of exposures in AP, and many yet remain unexamined, with the most consistent or strongest evidence to date being for obstetric complications, psychopathology, cognitive indicators and motor dysfunction. Among the few investigations affording direct comparison between SSD and AP, larger effect sizes and a greater number of significant associations are commonly reported for SSD relative to AP.

CONCLUSIONS

Shared risk factors for SSD and AP may include obstetric complications, childhood psychopathology, cognitive markers and motor dysfunction, but the capacity to distinguish common versus distinct risk factors/antecedents for SSD and AP is limited by the scant availability of prospective data for AP, and inconsistency in replication. Further studies considering both diagnoses concurrently are needed. Nonetheless, the prevalence of the risk factors/antecedents observed in cases and controls helps demarcate potential targets for preventative interventions for these disorders.

Body size at birth and psychiatric disorders among adolescents: a clinical study of 310 under-age inpatient adolescents in Northern Finland

BACKGROUND

Deviant birth measure is a risk factor for later somatic illness but also for later psychiatric disorders of the offspring. Only a few studies have examined the association of birth measures to later psychiatric disorders among adolescents. Studies on sex differences in these associations are scarce as well.

METHODS

The cases consisted of 508 adolescents (208 boys and 300 girls) aged 12-17 years, who were admitted to inpatient psychiatric hospitalization between 2001 and 2006. In addition, 478 healthy controls were derived from the Northern Finnish Birth Cohort 1986, born in approximately the same period and same area as the cases. Data of birth measures were collected from the National Birth Register for cases and from antenatal clinics for controls. Both cases and controls were interviewed using the Schedule for Affective Disorder and Schizophrenia for School-Age Children-Present and Lifetime (K-SADS-PL) to assess psychiatric disorders.

RESULTS

The adolescent patients were statistically significantly shorter and had higher ponderal index at birth compared to healthy controls. In addition, the age of the mothers at adolescent's birth was significantly younger in the patients than the controls. After controlling for various covariates, a 2.4-fold increased likelihood for internalizing disorders was seen among male adolescents with high ponderal index.

CONCLUSIONS

The association of birth measures to psychiatric disorders was confirmed in our study, particularly among male adolescents suffering from internalizing disorders. Further studies in larger adolescent samples are needed to confirm our findings and clear up the association of high ponderal index to specific psychiatric disorders.

Sex differences in first-episode psychosis and in people at ultra-high risk

Sex-related differences in the clinical expression and outcome of schizophrenia have long been recognized; this study set out to evaluate whether they extend to those subjects who are at high risk of developing psychosis. In a sample enrolled in two early intervention programs in northern Italy, patients with first-episode psychosis (FEP; n=152) were compared to patients at ultra-high risk of psychosis (UHR; n=106) on a series of sex-related clinical characteristics of schizophrenia. In both the FEP and the UHR samples, males outnumbered females. In FEP patients, women had been referred at an older age than men and had a shorter duration of untreated illness (DUI) and of untreated psychosis. In UHR patients no sex differences were found in age of onset or DUI. There was no diagnosis by sex interaction on symptoms severity or level of functioning at presentation. The limited number of women in both samples, and the exclusion of people who were older than 30 and of those with substance dependence may have reduced the extent of sex-related differences in this study. Sex differences of precipitating factors for psychosis might be worthy of further investigation.

Obstetrical complications and Apgar score in subjects at risk of psychosis

The objective of the study was to identify associations between a history of obstetrical complications (OCs) and the future development of symptoms indicating risk of psychosis (At Risk Mental State - ARMS). The frequency of OCs was assessed in 66 ARMS subjects, 50 subjects with the first episode of schizophrenia (FES) and 50 healthy controls. Obstetrical data was obtained from medical documentation and evaluated with the Lewis and Murray Scale. Definite OCs, according to the Lewis and Murray Scale, occurred significantly more frequently in the ARMS group compared to the controls (χ(2) = 7.79, p = 0.005; OR = 4.20, 95% CI = 1.46-12.11), as well as in the FES subjects compared to the controls (χ(2) = 8.39, p = 0.004; OR = 4.64, 95% CI = 1.56-13.20). Apgar scores in the first (Apgar 1) and the fifth minute after birth (Apgar 5) were significantly lower in the FES subjects compared to the controls (for Apgar 1 score Z = 4.439, p < 0.0001; for Apgar 5 score Z = 5.250, p < 0.0001). The ARMS subjects demonstrated significantly lower Apgar 5 scores compared to the healthy controls (Z = 3.458, p = 0.0016). The results indicate that OCs and low Apgar 5 score should be considered important factors in identifying subjects at risk of developing psychosis.

Neurodevelopment and inflammatory patterns in schizophrenia in relation to pathophysiology

As for other major psychoses, the etiology of schizophrenia still remains poorly understood, involving genetic and epigenetic mechanisms, as well as environmental contributions. In addition, immune alterations have been widely reported in schizophrenic patients, involving both the unspecific and specific pathways of the immune system, and suggesting that infectious/autoimmune processes play an important role in the etiopathogenesis of the disorder. Cytokines, in particular, are supposed to play a critical role in infectious and inflammatory processes, mediating the cross-talk between the brain and the immune system. In this perspective, even though mixed results have been reported, it seems that schizophrenia is associated with an imbalance in inflammatory cytokines. Alterations in the inflammatory and immune systems, moreover, seem to be already present in the early stages of schizophrenia and connected to the neurodevelopmental hypothesis of the disorder, identifying its roots in brain development abnormalities that do not manifest themselves until adolescence or early adulthood. At the same time, neuropathological and longitudinal studies in schizophrenia also support a neurodegenerative hypothesis and, more recently, a novel mixed hypothesis, integrating neurodevelopmental and neurodegenerative models, has been put forward. The present review aims to provide an updated overview of the connections between the immune and inflammatory alterations and the aforementioned hypotheses in schizophrenia.

Obstetric complications in early psychosis: relation with family history of psychosis

The people classified as being at ultra-high risk (UHR) of developing psychosis are expected to share many risk factors for psychosis with the patients diagnosed with schizophrenia, including an enhanced incidence of obstetric complications (OCs). This study set out to investigate the incidence and correlates of OCs in a sample of patients accessing an early intervention center. Patients' mothers were asked whether they had suffered from any somatic complication during pregnancy from a list of OCs with potential direct relevance to the physical wellbeing of the offspring. Out of 86 patients diagnosed with first-episode psychosis, 20 (23%) cases were positive for the occurrence of severe OCs, as reported by their mothers during an interview; out of 83 UHR patients, 21 (25%) cases were positive for OCs. OCs were more common in individuals with a family history of psychosis than in those without such a history. OCs might interact with genetic vulnerability to increase the risk of psychosis. Lack of comparison to healthy controls is a limitation that decreases the value of these findings.

Placental regulation of maternal-fetal interactions and brain development

A variety prenatal insults are associated with the incidence of neurodevelopmental disorders such as schizophrenia, autism and cerebral palsy. While the precise mechanisms underlying how transient gestational challenges can lead to later life dysfunctions are largely unknown, the placenta is likely to play a key role. The literal interface between maternal and fetal cells resides in the placenta, and disruptions to the maternal or intrauterine environment are necessarily conveyed to the developing embryo via the placenta. Placental cells bear the responsibility of promoting maternal tolerance of the semiallogeneic fetus and regulating selective permeability of nutrients, gases, and antibodies, while still providing physiological protection of the embryo from adversity. The placenta's critical role in modulating immune protection and the availability of nutrients and endocrine factors to the offspring implicates its involvement in autoimmunity, growth restriction and hypoxia, all factors associated with the development of neurological complications. In this review, we summarize primary maternal-fetal interactions that occur in the placenta and describe pathways by which maternal insults can impair these processes and disrupt fetal brain development. We also review emerging evidence for placental dysfunction in the prenatal programming of neurodevelopmental disorders.

Exposure to obstetric complications in relation to subsequent psychiatric disorders of adolescent inpatients: specific focus on gender differences

BACKGROUND

Exposure to obstetric complications is known to be associated with subsequent development of psychiatric disorders. However, earlier findings are mainly based on adult populations having a long follow-up time for onset of psychiatric illness. We examined whether the association of obstetric complications with severe mental disorders is already seen in a population of underage adolescents admitted to psychiatric inpatient care.

METHOD

The study population was a clinical sample of adolescents (n = 508) aged 12-17 years admitted to psychiatric hospital. DSM-IV diagnoses of the psychiatric disorders of the adolescents as well as information on obstetric (i.e., pregnancy, delivery and perinatal) complications and substance use during pregnancy reported by the mothers of the adolescents were based on the semi-structured Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime.

RESULTS

A total of 96 (19%) adolescents had been exposed to obstetric complications. The prevalence of pregnancy, delivery or perinatal complications reported by the mothers of the offspring was 55 (57%), 57 (59%) and 13 (14%), respectively. Among adolescents with conduct disorder, exposure to delivery complications was more common among males compared to females (16 vs. 5%, p = 0.006); this was particularly true for section delivery (7 vs. 1%, p = 0.023). A trend towards a significant gender difference was also found among adolescents with anxiety disorder (21 vs. 8%, p = 0.085).

CONCLUSIONS

Boys seem to be more vulnerable to the exposure of delivery complications than girls. Exposure to obstetric complication may be associated with development of subsequent psychiatric disorder; particularly conduct disorder of adolescent boys.

Stress-related methylation of the catechol-O-methyltransferase Val 158 allele predicts human prefrontal cognition and activity

DNA methylation at CpG dinucleotides is associated with gene silencing, stress, and memory. The catechol-O-methyltransferase (COMT) Val(158) allele in rs4680 is associated with differential enzyme activity, stress responsivity, and prefrontal activity during working memory (WM), and it creates a CpG dinucleotide. We report that methylation of the Val(158) allele measured from peripheral blood mononuclear cells (PBMCs) of Val/Val humans is associated negatively with lifetime stress and positively with WM performance; it interacts with stress to modulate prefrontal activity during WM, such that greater stress and lower methylation are related to reduced cortical efficiency; and it is inversely related to mRNA expression and protein levels, potentially explaining the in vivo effects. Finally, methylation of COMT in prefrontal cortex and that in PBMCs of rats are correlated. The relationship of methylation of the COMT Val(158) allele with stress, gene expression, WM performance, and related brain activity suggests that stress-related methylation is associated with silencing of the gene, which partially compensates the physiological role of the high-activity Val allele in prefrontal cognition and activity. Moreover, these results demonstrate how stress-related DNA methylation of specific functional alleles impacts directly on human brain physiology beyond sequence variation.

Schizophrenia, cancer and obstetric complications in an evolutionary perspective-an empirically based hypothesis

OBJECTIVE

Patients diagnosed with schizophrenia have reduced fecundity and premature mortality (both accidental and violent) with no obvious compensatory advantages among kin. The prevalence of the disorder is around 0.7/1%, higher than the expected prevalence of spontaneous mutations. Genes favoring schizophrenia may have been positively selected in the environment of evolutionary adaptation. Literature on potential adaptive genes is reviewed within an evolutionary framework.

METHODS

Literature search on major scientific search engine (PubMed/Medline, Ovid/PsychInfo) on papers aimed at investigating potential pathways justifying a mutation-selection balanced model. Findings are presented with a narrative touch to favor readability and understanding.

RESULTS

Reduced incidence of cancer in both patients diagnosed with schizophrenia and their siblings was reported worldwide. Such findings are notable given higher cancer risk factors in schizophrenia, i.e., smoking, alcohol abuse, obesity, poor diet, and poor adherence to therapy. Some genes involved in cancer proliferation might as well confer protective advantage in immune-surveillance, inflammation, vascular proliferation or apoptosis that otherwise will adversely affect early neurodevelopment.

CONCLUSION

Evidence that reduced risk of certain somatic diseases is associated with schizophrenia is quite significant to progress in the evolutionary epidemiological analysis of psychopathology.

Activation of the maternal immune system induces endocrine changes in the placenta via IL-6

Activation of the maternal immune system in rodent models sets in motion a cascade of molecular pathways that ultimately result in autism- and schizophrenia-related behaviors in offspring. The finding that interleukin-6 (IL-6) is a crucial mediator of these effects led us to examine the mechanism by which this cytokine influences fetal development in vivo. Here we focus on the placenta as the site of direct interaction between mother and fetus and as a principal modulator of fetal development. We find that maternal immune activation (MIA) with a viral mimic, synthetic double-stranded RNA (poly(I:C)), increases IL-6 mRNA as well as maternally-derived IL-6 protein in the placenta. Placentas from MIA mothers exhibit increases in CD69+ decidual macrophages, granulocytes and uterine NK cells, indicating elevated early immune activation. Maternally-derived IL-6 mediates activation of the JAK/STAT3 pathway specifically in the spongiotrophoblast layer of the placenta, which results in expression of acute phase genes. Importantly, this parallels an IL-6-dependent disruption of the growth hormone-insulin-like growth factor (GH-IGF) axis that is characterized by decreased GH, IGFI and IGFBP3 levels. In addition, we observe an IL-6-dependent induction in pro-lactin-like protein-K (PLP-K) expression as well as MIA-related alterations in other placental endocrine factors. Together, these IL-6-mediated effects of MIA on the placenta represent an indirect mechanism by which MIA can alter fetal development.

Differences in maternal and paternal age between schizophrenia and other psychiatric disorders

Advanced parental age has been shown to increase offspring risk for a number of neuropsychiatric disorders including schizophrenia and Down's syndrome. Other psychiatric disorders have been less studied with respect to the effect of parental age on offspring risk. In this study we examine if advanced parental age increased risk for ICD-10 diagnoses. We hypothesized that advanced parental age would increase risk for offspring psychotic disorders and mental retardation but not other ICD-10 diagnoses. We examined follow-up data for 30,965 subjects treated in outpatient psychiatric facilities between 1980 and 2007. Subjects were younger than 18 years of age at their first outpatient visit. A comparison group was obtained from data on registered births in Spain from 1975. We compared parental age (maternal, paternal, combined) across diagnostic categories using ANOVA and logistic regression was used to estimate the risk of psychopathology in the offspring with advanced parental age (maternal, paternal, combined). Maternal and paternal ages were higher for subjects diagnosed with mental retardation. Risk for psychotic disorders showed a significant linear increase only with advancing maternal age, and not paternal age as is more often reported.

AKT1 Gene Polymorphisms and Obstetric Complications in the Patients with Schizophrenia

OBJECTIVE

We performed a genetic association study with schizophrenic patients to investigate whether the V-akt murine thymoma viral oncogene homolog 1 (AKT1) gene plays a role in obstetric complications.

METHODS

One-hundred-eighty patients with schizophrenia (male, 113; female, 67) were included. All patients fulfilled DSM-IV criteria for schizophrenia. Obstetric complications were measured by the Lewis scale. Prenatal and perinatal information was retrospectively collected from the patients' mothers. We selected six single nucleotide polymorphisms (SNPs) for the AKT1 gene: SNP1 (rs3803300), SNP2 (rs1130214), SNP3 (rs3730358), SNP4 (rs 1130233), SNP5 (rs2494732), and SNPA (rs2498804). The genotype data were analyzed for an association with the Lewis total score in terms of allele, genotype, and haplotype distribution.

RESULTS

The mean total Lewis scores were 1.30+/-1.61 for males and 1.54+/-1.87 for females. Higher total score tended to be correlated with an earlier age of onset of schizophrenia in females. In the total sample, no SNP was associated with obstetric complications. However, the additional analyses for male and female subgroups found a significant association between SNPA and SNP4 and Lewis score in females (p=0.02 for SNPA, p=0.04 for SNP4). The SNP5-SNPA haplotype showed a positive association with obstetric complications (p=0.03) in the female patient group.

CONCLUSION

We found an association between SNPs in the AKT1 gene and total Lewis score measuring obstetric complications in female patients with schizophrenia. Because these findings did not survive a correction for multiple testing, the significance should be interpreted carefully and replication studies are required.

Schizophrenia: genetics, prevention and rehabilitation

OBJECTIVE

Genetic factors are largely implicated in predisposing to schizophrenia. Environmental factors contribute to the onset of the disorder in individuals at increased genetic risk. Cognitive deficits have emerged as endophenotypes and potential therapeutic targets for schizophrenia because of their association with functional outcome. The aims of this review were to analyse the joint effect of genetic and environmental (G×E) factors on liability to schizophrenia and to investigate relationships between genes and cognitive endophenotypes focusing on practical applications for prevention and rehabilitation.

METHODS

Medline search of relevant studies published between 1990 and 2008.

RESULTS

In schizophrenia, examples of G×E interaction include the catechol-O-methyl transferase (COMT) (Val158Met) polymorphism, which was found to moderate the onset of psychotic manifestations in response to stress and to increase the risk for psychosis related to cannabis use, and neurodevelopmental genes such as AKT1 (serine-threonine kinase), brain-derived neurotrophic factor (BDNF), DTNBP1 (dysbindin) and GRM3 (metabotropic glutamate receptor 3), which were associated with development of schizophrenia in adulthood after exposure to perinatal obstetric complications. Neurocognitive deficits are recognised as core features of schizophrenia that facilitate the onset of the disorder and have a great impact on functional outcome. Neurocognitive deficits are also endophenotypes that have been linked to a variety of genes [COMT, neuregulin (NRG1), BDNF, Disrupted-In-Schizophrenia 1 (DISC1) and dysbindin] conferring susceptibility to schizophrenia. Recently, it has emerged that cognitive improvement during rehabilitation therapy was under control of COMT (Val158Met) polymorphism.

CONCLUSION

This review could indicate a pivotal role of psychiatric genetics in prevention and rehabilitation of schizophrenic psychoses.

The neurodevelopmental hypothesis of schizophrenia, revisited

While multiple theories have been put forth regarding the origin of schizophrenia, by far the vast majority of evidence points to the neurodevelopmental model in which developmental insults as early as late first or early second trimester lead to the activation of pathologic neural circuits during adolescence or young adulthood leading to the emergence of positive or negative symptoms. In this report, we examine the evidence from brain pathology (enlargement of the cerebroventricular system, changes in gray and white matters, and abnormal laminar organization), genetics (changes in the normal expression of proteins that are involved in early migration of neurons and glia, cell proliferation, axonal outgrowth, synaptogenesis, and apoptosis), environmental factors (increased frequency of obstetric complications and increased rates of schizophrenic births due to prenatal viral or bacterial infections), and gene-environmental interactions (a disproportionate number of schizophrenia candidate genes are regulated by hypoxia, microdeletions and microduplications, the overrepresentation of pathogen-related genes among schizophrenia candidate genes) in support of the neurodevelopmental model. We relate the neurodevelopmental model to a number of findings about schizophrenia. Finally, we also examine alternate explanations of the origin of schizophrenia including the neurodegenerative model.

Serious obstetric complications interact with hypoxia-regulated/vascular-expression genes to influence schizophrenia risk

The etiology of schizophrenia is thought to include both epistasis and gene-environment interactions. We sought to test whether a set of schizophrenia candidate genes regulated by hypoxia or involved in vascular function in the brain (AKT1, BDNF, CAPON, CHRNA7, COMT, DTNBP1, GAD1, GRM3, NOTCH4, NRG1, PRODH, RGS4, TNF-alpha) interacted with serious obstetric complications to influence risk for schizophrenia. A family-based study of transmission disequilibrium was conducted in 116 trios. Twenty-nine probands had at least one serious obstetric complication (OC) using the McNeil-Sjostrom Scale, and many of the OCs reported were associated with the potential for fetal hypoxia. Analyses were conducted using conditional logistic regression and a likelihood ratio test (LRT) between nested models was performed to assess significance. Of the 13 genes examined, four (AKT1 (three SNPs), BDNF (two SNPs), DTNBP1 (one SNP) and GRM3 (one SNP)) showed significant evidence for gene-by-environment interaction (LRT P-values ranged from 0.011 to 0.037). Although our sample size was modest and the power to detect interactions was limited, we report significant evidence for genes involved in neurovascular function or regulated by hypoxia interacting with the presence of serious obstetric complications to increase risk for schizophrenia.

Effect of Rhesus D incompatibility on schizophrenia depends on offspring sex

Rhesus D incompatibility increases risk for schizophrenia, with some evidence that risk is limited to male offspring. The purpose of this study is to determine whether risk for schizophrenia due to Rhesus D incompatibility differs by offspring sex using a nuclear family-based candidate gene approach and a meta-analysis approach. The genetic study is based on a sample of 277 nuclear families with RHD genotype data on at least one parent and at least one child diagnosed with schizophrenia or related disorder. Meta-analysis inclusion criteria were (1) well-defined sample of schizophrenia patients with majority born before 1970, (2) Rhesus D incompatibility phenotype or genotype data available on mother and offspring, and by offspring sex. Two of ten studies, plus the current genetic study sample, fulfilled these criteria, for a total of 358 affected males and 226 affected females. The genetic study found that schizophrenia risk for incompatible males was significantly greater than for compatible offspring (p=0.03), while risk for incompatible and compatible females was not significantly different (p=.32). Relative risks for incompatible males and females were not significantly different from each other. Meta-analysis using a larger number of affected males and females supports their difference. Taken together, these results provide further support that risk of schizophrenia due to Rhesus D incompatibility is limited to incompatible males, although a weak female incompatibility effect cannot be excluded. Sex differences during fetal neurodevelopment should be investigated to fully elucidate the etiology of schizophrenia.

Obstetrical complications in people at risk for developing schizophrenia

Many factors have been associated with the development of schizophrenia, yet few studies have looked at these same factors in individuals considered at risk for schizophrenia, but who have not yet reached diagnostic threshold. The rate of obstetrical complications was assessed as part of a comprehensive battery in subjects at risk (N=52), or in the first episode of schizophrenia (N=18), and in normal comparison subjects (N=43). The rate of obstetrical complications was increased in the at risk (46%) and first episode (39%) samples compared to the normal comparison (19%) group, however, follow-up analyses were only significant between the at risk and normal comparison subjects. Obstetrical complications may be an important risk factor in identifying vulnerable subjects and ultimately may, along with other risk factors, be part of an algorithm for determining likelihood of developing schizophrenia.

Physical illness and schizophrenia: a review of the literature

OBJECTIVE

The lifespan of people with schizophrenia is shortened compared to the general population. We reviewed the literature on comorbid physical diseases in schizophrenia to provide a basis for initiatives to fight this unacceptable situation.

METHOD

We searched MEDLINE (1966 - May 2006) combining the MeSH term of schizophrenia with the 23 MeSH terms of general physical disease categories to identify relevant epidemiological studies.

RESULTS

A total of 44 202 abstracts were screened. People with schizophrenia have higher prevalences of HIV infection and hepatitis, osteoporosis, altered pain sensitivity, sexual dysfunction, obstetric complications, cardiovascular diseases, overweight, diabetes, dental problems, and polydipsia than the general population. Rheumatoid arthritis and cancer may occur less frequently than in the general population. Eighty-six per cent of the studies came from industrialized countries limiting the generalizability of the findings.

CONCLUSION

The increased frequency of physical diseases in schizophrenia might be on account of factors related to schizophrenia and its treatment, but undoubtedly also results from the unsatisfactory organization of health services, from the attitudes of medical doctors, and the social stigma ascribed to the schizophrenic patients.

[Reproduction and psyche]

Mental health and mental disorders can have a close connection to reproduction, especially for women but also for men. The most frequent disorders or problems are described, i.e., mental problems during pregnancy and after delivery, during the menstrual cycle and around menopause. Possible consequences of miscarriage, stillbirth and induced abortion are presented as well as the special problem of a wish for a child in mentally ill women and their treatment during pregnancy.

Poor maternal care and high maternal body mass index in pregnancy as a risk factor for schizophrenia in offspring

OBJECTIVE

We investigated whether antenatal factors in mothers would increase the risk of schizophrenia in the offspring, and also examined any relationship between these factors and histories of obstetric complications (OCs).

METHOD

Using the Mother and Child Health Handbooks of 52 patients with schizophrenia and 284 healthy subjects, we evaluated the risk-increasing effects of the frequency of antenatal care visits and mothers' body mass index (BMI) at both early and late pregnancy.

RESULTS

In logistic regression analysis, there was a significant association between the number of antenatal care visits and the risk of the disorder; an increase in a unit of visits corresponds to a reduction of the risk by 12%. We also found a 24% increase in the risk with a one-unit increase of BMI at the early pregnancy, and a 19% increase at the late pregnancy. These antenatal factors were found to contribute, in part, to an excess of OCs in individuals with schizophrenia.

CONCLUSION

Poor maternal care during pregnancy and comparatively high maternal BMI especially at early pregnancy may cause a predisposition to schizophrenia in the offspring.

Birth insult interacts with stress at adulthood to alter dopaminergic function in animal models: possible implications for schizophrenia and other disorders

Altered subcortical dopaminergic activity is thought to be involved in the pathophysiology of several disorders including schizophrenia, substance abuse and attention deficit hyperactivity disorder. Epidemiological studies have implicated perinatal insults, particularly obstetric complications involving fetal or neonatal hypoxia, as etiological risk factors for schizophrenia. This suggests the possibility that perinatal hypoxia might have lasting effects on dopaminergic function. In animal models, dopaminergic systems appears to be particularly vulnerable to a wide range of perinatal insults, resulting in persistent alterations in function of mesolimbic and mesostriatal pathways. This review summarizes recent work characterizing long-term changes in dopaminergic function and biochemistry in models of Caesarean section (C-section) birth and of C-section birth with added global anoxia in the rat and guinea pig. C-section birth and C-section with anoxia appear to be two distinct hypoxic birth insults, with somewhat differing patterns of lasting effects on dopamine systems. In addition, birth insult alters the manner in which dopaminergic function is regulated by stress at adulthood. The possible relevance of these finding to effects of human birth procedures is discussed.

Age-at-onset and schizophrenia: reversed gender effect

OBJECTIVE

This study seeks an explanation for reversed gender effect on age-at-onset (AAO) in schizophrenia. The hypothesis is older AAO in males would be detected in a sample where higher infant mortality (IMR) prevailed.

METHOD

Case records of International Classification of Diseases-10 (ICD-10) schizophrenia patients from two states (n=70 each) with an IMR of 13 and 67 per thousand were reviewed and AAO was obtained by using the recorded age and duration of illness.

RESULTS

In the sample from the state with lower IMR, AAO did not differ between the two sexes. However, men had older AAO than women in the state with fivefold higher IMR.

CONCLUSION

Gender differences in AAO may be a function of perinatal complications. In places where infants with perinatal complications are less likely to survive, hence high IMR, a small group of potentially youngest AAO schizophrenic males may be eliminated thus changing the gender effect on AAO.

Obstetric complications and Apgar score in early-onset schizophrenic patients with prominent positive and prominent negative symptoms

The objective of the study was to find associations between obstetric complications (OCs) history and schizophrenia course and symptoms. We analysed the obstetric and psychiatric history of 50 DSM IV schizophrenic subjects who experienced their first schizophrenia episode in adolescence, and 30 healthy controls. Obstetrical data and Apgar scores were obtained from medical records and evaluated with the Lewis and Murray Scale. Based on patients' documentation [including longitudinal evaluation with Positive and Negative Syndrome Scale (PANSS)] the symptom profile and the course of schizophrenia were determined.

RESULTS

we distinguished two major groups of patients: with prominent negative and prominent positive symptoms. Schizophrenics with prominent negative symptoms and a chronic schizophrenia course had significantly more definite OCs and lower Apgar scores than patients with prominent positive symptoms and controls. Subjects who had a positive OCs history were more than four times likely to develop schizophrenia in adolescence than those without such a history (OR=4.64; 95% CI=1.29-17.51) with the likelihood of developing schizophrenia with prominent negative symptoms especially high (OR=7.31; 95% CI=1.80-29.65). An Apgar score of between 0 and 3 after birth was associated with an increased risk for developing schizophrenia (OR=2.25; 95% CI=0.56-9.12), especially with prominent negative symptoms (OR=3.71; 95% CI=0.84-16.32). The findings support the hypothesis of a role of OCs in developing early-onset schizophrenia and suggest the associations of the OCs history with a specific symptoms profile (prominent negative symptoms) and a chronic course of schizophrenia.