Schizophrenia: An Update and Review

Disrupted hippocampal synchrony following maternal immune activation in a rat model

Maternal immune activation (MIA) is a risk factor for schizophrenia and other neurodevelopmental disorders. MIA in rats models a number of the brain and behavioral changes that are observed in schizophrenia, including impaired memory. Recent studies in the MIA model have shown that the firing of the hippocampal place cells that are involved in memory processes appear relatively normal, but with abnormalities in the temporal ordering of firing. In this study, we re-analyzed data from prior hippocampal electrophysiological recordings of MIA and control animals to determine whether temporal dysfunction was evident. We find that there is a decreased ratio of slow to fast gamma power, resulting from an increase in fast gamma power and a tendency toward reduced slow gamma power in MIA rats. Moreover, we observe a robust reduction in spectral coherence between hippocampal theta and both fast and slow gamma rhythms, as well as changes in the phase of theta at which fast gamma occurs. We also find the phasic organization of place cell phase precession on the theta wave to be abnormal in MIA rats. Lastly, we observe that the local field potential of MIA rats contains more frequent sharp-wave ripple events, and that place cells were more likely to fire spikes during ripples in these animals than control. These findings provide further evidence of desynchrony in MIA animals and may point to circuit-level changes that underlie failures to integrate and encode information in schizophrenia.

Recent Updates on Corticosteroid-Induced Neuropsychiatric Disorders and Theranostic Advancements through Gene Editing Tools

The vast use of corticosteroids (CCSs) globally has led to an increase in CCS-induced neuropsychiatric disorders (NPDs), a very common manifestation in patients after CCS consumption. These neuropsychiatric disorders range from depression, insomnia, and bipolar disorders to panic attacks, overt psychosis, and many other cognitive changes in such subjects. Though their therapeutic importance in treating and improving many clinical symptoms overrides the complications that arise after their consumption, still, there has been an alarming rise in NPD cases in recent years, and they are seen as the greatest public health challenge globally; therefore, these potential side effects cannot be ignored. It has also been observed that many of the neuronal functional activities are regulated and controlled by genomic variants with epigenetic factors (DNA methylation, non-coding RNA, and histone modeling, etc.), and any alterations in these regulatory mechanisms affect normal cerebral development and functioning. This study explores a general overview of emerging concerns of CCS-induced NPDs, the effective molecular biology approaches that can revitalize NPD therapy in an extremely specialized, reliable, and effective manner, and the possible gene-editing-based therapeutic strategies to either prevent or cure NPDs in the future.

Effects of Brain Atlases and Machine Learning Methods on the Discrimination of Schizophrenia Patients: A Multimodal MRI Study

Recently, machine learning techniques have been widely applied in discriminative studies of schizophrenia (SZ) patients with multimodal magnetic resonance imaging (MRI); however, the effects of brain atlases and machine learning methods remain largely unknown. In this study, we collected MRI data for 61 first-episode SZ patients (FESZ), 79 chronic SZ patients (CSZ) and 205 normal controls (NC) and calculated 4 MRI measurements, including regional gray matter volume (GMV), regional homogeneity (ReHo), amplitude of low-frequency fluctuation and degree centrality. We systematically analyzed the performance of two classifications (SZ vs NC; FESZ vs CSZ) based on the combinations of three brain atlases, five classifiers, two cross validation methods and 3 dimensionality reduction algorithms. Our results showed that the groupwise whole-brain atlas with 268 ROIs outperformed the other two brain atlases. In addition, the leave-one-out cross validation was the best cross validation method to select the best hyperparameter set, but the classification performances by different classifiers and dimensionality reduction algorithms were quite similar. Importantly, the contributions of input features to both classifications were higher with the GMV and ReHo features of brain regions in the prefrontal and temporal gyri. Furthermore, an ensemble learning method was performed to establish an integrated model, in which classification performance was improved. Taken together, these findings indicated the effects of these factors in constructing effective classifiers for psychiatric diseases and showed that the integrated model has the potential to improve the clinical diagnosis and treatment evaluation of SZ.

New Path to Recovery and Well-Being: Cross-Sectional Study on WeChat Use and Endorsement of WeChat-Based mHealth Among People Living With Schizophrenia in China

Background

The past few decades have seen an exponential increase in using mobile phones to support medical care (mobile health [mHealth]) among people living with psychosis worldwide, yet little is known about WeChat use and WeChat-based mHealth among people living with schizophrenia (PLS) in China.

Objective

This study aims to assess WeChat use, endorsement of WeChat-based mHealth programs, and health related to WeChat use among PLS.

Methods

We recruited a random sample of 400 PLS from 12 communities in Changsha City of Hunan Province, China. WeChat use was assessed using the adapted WeChat Use Intensity Questionnaire (WUIQ). We also compared psychiatric symptoms, functioning, disability, recovery, quality of life, and general well-being between WeChat users and nonusers using one-to-one propensity-score matching.

Results

The WeChat use rate was 40.8% in this sample (163/400); 30.7% (50/163) had more than 50 WeChat friends and nearly half (81/163, 49.7%) spent more than half an hour on WeChat, a pattern similar to college students and the elderly. PLS also showed higher emotional connectedness to WeChat use than college students. About 80.4% (131/163) of PLS were willing to participate in a WeChat-based mHealth program, including psychoeducation (91/163, 55.8%), professional support (82/163, 50.3%), and peer support (67/163, 41.1%). Compared with nonusers, WeChat users were younger, better educated, and more likely to be employed. WeChat use was associated with improved health outcomes, including lower psychiatric symptoms, lower depression, higher functioning, better recovery, and higher quality of life.

Conclusions

WeChat-based mHealth programs hold promise as an empowering tool to provide cost-effective interventions, to foster global recovery, and to improve both physical and mental well-being among PLS. WeChat and WeChat-based mHealth programs have the potential to offer a new path to recovery and well-being for PLS in China.

Association of DTNBP1 With Schizophrenia: Findings From Two Independent Samples of Han Chinese Population

OBJECTIVES

Schizophrenia (SZ) is a complex psychiatric disorder that has a strong genetic basis. Dystrobrevin-binding protein 1 (DTNBP1) is one of the genes thought to be pivotal in regulating the glutamatergic system. Studies have suggested that variations in DTNBP1 confer susceptibility to SZ and clinical symptoms. Here, we performed a two-stage independent verification study to identify polymorphisms of the DTNBP1 gene that might be associated with SZ in the Han Chinese population.

METHODS

In stage 1, 14 single nucleotide polymorphisms (SNPs) were genotyped in 528 paranoid SZ patients and 528 healthy controls (HCs) using the Illumina GoldenGate assays on a BeadStation 500G Genotyping System. In stage 2, ten SNPs were genotyped in an independent sample of 1,031 SZ patients and 621 HCs using the Illumina 660k Genotyping System. Clinical symptoms were assessed using the Positive and Negative Syndrome Scale.

RESULTS

There was a significant association related to allele frequency, and a trend association in relation to genotype between SZ patients and HCs at rs4712253 (p = 0.03 and 0.05, respectively). These associations were not evident following Bonferroni correction (p > 0.05 for both). Haplotype association analysis revealed that only two haplotypes (GAG and GAA; rs16876575-rs9464793-rs4712253) were significantly different between SZ patients and HCs (χ² = 4.24, 6.37, p = 0.04 and 0.01, respectively). In addition, in SZ patients there was a significant association in the rs4964793 genotype for positive symptoms, and in the rs1011313 genotype for excitement/hostility symptoms (p = 0.01 and 0.002, respectively). We found a significant association in the baseline symbol digital modalities test (SDMT), forward-digital span (DS), backward-DS, and semantic fluency between SZ patients and HCs (p < 0.05 for all). Finally, the SNP rs1011313 genotypes were associated with SDMT in SZ patients (p = 0.04).

CONCLUSION

This study provides further evidence that SNP rs4712253 of DTNBP1 has a nominal association with SZ in the Han Chinese population. Such a genotype variation may play a role in psychopathology and cognitive function.

Genetic Variations of DAOA (rs947267 and rs3918342) and COMT Genes (rs165599 and rs4680) in Schizophrenia and Bipolar I Disorder

Introduction:

Genetic and environmental factors are involved in the incidence of schizophrenia and bipolar disorder. Many reports confirm that several common genes are connected with these two psychotic disorders. Several neurotransmitters may be involved in the molecular mechanisms of schizophrenia and bipolar disorder. We aimed to estimate the role of two talent genes: DAOA in neurotransmission of glutamate and COMT in neurotransmission of dopamine to guide the treatment of schizophrenia and bipolar disorder.

Methods:

Blood samples (n=100 for schizophrenia, n=100 for bipolar I disorder and n=127 for case control) were collected from individuals unrelated in the southwest of Iran. The SNPs (rs947267 and rs3918342 for DAOA gene/rs165599 and rs4680 for COMT gene) were genotyped using the PCR-RFLP method. Our finding was studied by logistic regression and Mantel-Haenszel Chi-square tests.

Results:

We observed an association in rs3918342, rs165599 and rs4680 single nucleotide polymorphisms and schizophrenia and bipolar I disorder. In addition, our data demonstrated that the rs947267 was related to bipolar I disorder but there was no association between this SNP and schizophrenia.

Conclusion:

In conclusion, this result supports the hypothesis that variations in DAOA and COMT genes may play a role in schizophrenia and bipolar disorder.

Parental characteristics and the risk of schizophrenia in a Chinese population: a case-control study

BACKGROUND

Genetic studies have provided convergent results indicating that schizophrenia is a polygenic disorder with a heritability estimate of ∼60-80%. The propensity for schizophrenia is ∼10 times higher in individuals with first-degree relatives with schizophrenia when compared to the general population.

AIM

To identify associations between parental characteristics and the risk of schizophrenia in a Chinese population.

METHODS

Participants with a diagnosis of schizophrenia were recruited along with healthy controls (HCs) matched for age and gender from Weifang, China. Logistic regression models and generalized linear models were used to explore the associations between parental characteristics with the risk and age at onset of schizophrenia. In total, 414 cases and 639 HCs were recruited for the study.

RESULTS

We observed an inverse association between levels of paternal and maternal education and risk of schizophrenia after controlling for potential confounders (Paternal: OR = 1.525, 95% CI: 1.080-2.153, p = .017; Maternal: OR = 1.984, 95% CI: 1.346-2.924, p = .001). Younger paternal and maternal childbearing age were associated with a higher risk of diagnosis of schizophrenia. We furtherly observed that individuals with earlier age at onset of schizophrenia had fewer siblings (p = .007) and had higher rates of parental marital disharmony (p = .033).

CONCLUSION

Our results indicate that parental years of education and age of childbearing are associated with an increased risk of schizophrenia in a Chinese population. Age of onset of schizophrenia was positively associated with a greater number of siblings and negatively associated with parental marital disharmony.

A positive-psychological intervention reduces acute psychosis-proneness

BACKGROUND

While individuals at ultra-risk for schizophrenia are characterized by high negative/disorganised but low positive schizotypy, schizophrenia patients are usually high in all three schizotypy facets. Thus, avoiding increases in positive schizotypy in ultra-high risk individuals may constitute of form of schizophrenia-prevention. A possible method of reducing positive schizotypy could be Positive-Psychological intervention (PI).

METHODS

We present results from 2 independent studies, including a 12-month follow-up from study 1, using an easy-to-perform intervention based on Positive Psychology to reduce positive schizotypy.

RESULTS

A PI can significantly and sustainably reduce positive schizotypy compared to a placebo-condition. Furthermore, our results show very high response-rates to said intervention, with responsiveness to the intervention increasing significantly with disorganised schizotypic traits.

CONCLUSIONS

As especially disorganised schizotypy is of relevance for the risk of transition from high benign schizotypy to schizophrenia and is found most closely associated to familial schizophrenia-risk and highly elevated in at-risk mental states, our results are encouraging. We suggest, thus, that positive psychology can not only reduce positive schizotypy, but may be increasingly useful with rising schizophrenia-risk and, thus, be worthy of further investigation regarding it potential in schizophrenia-prevention.

Association between cerebral dopamine neurotrophic factor (CDNF) 2 polymorphisms and schizophrenia susceptibility and symptoms in the Han Chinese population

Background

Schizophrenia (SZ) is a complex polygenic psychiatric disorder caused in part by abnormal dopamine levels. Cerebral dopamine neurotrophic factor (CDNF) 2 is known to protect and repair the dopaminergic system. Dopamine dysfunction is one of the pathogenesis of SZ. However, the relationship between CDNF2 and SZ has not been previously investigated. We speculated that CDNF2 may be a susceptibility factor for SZ.

Methods

To address this issue, we carried out a study to investigate the association between CDNF2 and SZ in the total sample 1371 (670 SZ patients and 701 healthy controls) Han Chinese population. Stage 1 included 528 SZ patients and 528 healthy controls; and stage 2 included 142 SZ patients and 173 healthy controls. The allele and genotype frequencies of five single nucleotide polymorphisms (rs2577074, rs2577075, rs2249810, rs6506891, and rs2118343) of CDNF2 were compared between patients and controls.

Results

We found a significant association in allele and genotype frequencies between the two groups at rs2249810 (χ² = 4.38 and 6.45, respectively; P = 0.03 and 0.04, respectively). An association was also observed in males at rs2249810 (χ² = 8.76; P = 0.03). Haplotype TGATC differed between SZ and controls in stage 2 samples (χ² = 6.38; P = 0.01), and rs2118343 genotypes were associated with negative factor scores (F = 4.396; P = 0.01).

Conclusions

These results suggest that rs2249810 and haplotype TGATC of CDNF2 are an SZ susceptibility locus and factor, respectively, and that rs2118343 genotypes are associated with negative symptoms of SZ in the Han Chinese population.

Role of calcium channels in bipolar disorder

Bipolar disorder is characterized by a host of sleep-wake abnormalities that suggests that the reticular activating system (RAS) is involved in these symptoms. One of the signs of the disease is a decrease in high frequency gamma band activity, which accounts for a number of additional deficits. Bipolar disorder has also been found to overexpress neuronal calcium sensor protein 1 (NCS-1). Recent studies showed that elements in the RAS generate gamma band activity that is mediated by high threshold calcium (Ca2+) channels. This mini-review provides a description of recent findings on the role of Ca2+ and Ca2+ channels in bipolar disorder, emphasizing the involvement of arousal-related systems in the manifestation of many of the disease symptoms. This will hopefully bring attention to a much-needed area of research and provide novel avenues for therapeutic development.

Association Study of N-Methyl-D-Aspartate Receptor Subunit 2B (GRIN2B) Polymorphisms and Schizophrenia Symptoms in the Han Chinese Population

Schizophrenia (SZ) is a common and complex psychiatric disorder that has a significant genetic component. The glutamatergic system is the major excitatory neurotransmitter system in the central nervous system, and is mediated by N-methyl-D-aspartate (NMDA) receptors. Disturbances in this system have been hypothesized to play a major role in SZ pathogenesis. Several studies have revealed that the NMDA receptor subunit 2B (GRIN2B) potentially associates with SZ and its psychiatric symptoms. In this study, we performed a case–control study to identify polymorphisms of the GRIN2B gene that may confer susceptibility to SZ in the Han Chinese population. Thirty-four single nucleotide polymorphisms (SNPs) were genotyped in 528 paranoid SZ patients and 528 control subjects. A significant association was observed in allele and genotype between SZ and controls at rs2098469 (χ² = 8.425 and 4.994; p = 0.025 and 0.014, respectively). Significant associations were found in the allele at rs12319804 (χ² = 4.436; p = 0.035), as well as in the genotype at rs12820037 and rs7298664 between SZ and controls (χ² = 11.162 and 38.204; p = 0.003 and 4.27×10^-8, respectively). After applying the Bonferroni correction, rs7298664 still had significant genotype associations with SZ (p = 1.71×10^-7). In addition, rs2098469 genotype and allele frequencies, and 12820037 allele frequencies were nominally associated with SZ. Three haplotypes, CGA (rs10845849—rs12319804—rs10845851), CC (rs12582848—rs7952915), and AAGAC (rs2041986—rs11055665—rs7314376—rs7297101—rs2098469), had significant differences between SZ and controls (χ² = 4.324, 4.582, and 4.492; p = 0.037, 0.032, and 0.034, respectively). In addition, three SNPs, rs2098469, rs12820037, and rs7298664, were significantly associated with cognition factors PANSS subscores in SZ (F = 16.799, 7.112, and 13.357; p = 0.000, 0.017, and 0.000, respectively). In conclusion, our study provides novel evidence for an association between GRIN2B polymorphisms and SZ susceptibility and symptoms in the Han Chinese population.

[22q11.2DS Syndrome as a Genetic Subtype of Schizophrenia]

INTRODUCTION

The 22q11.2 deletion syndrome (22q11.2DS) is associated with the microdeletion of this chromosomal region, and represents the second most common genetic syndrome after Down's syndrome. In patients with schizophrenia, 22q11.2DS has a prevalence of 2%, and in selected groups can be increased to between 32-53%.

OBJECTIVE

To describe the generalities of 22q11.2DS syndrome as a genetic subtype of schizophrenia, its clinical characteristics, molecular genetic aspects, and frequency in different populations.

METHODS

A review was performed from 1967 to 2013 in scientific databases, compiling articles about 22q11.2DS syndrome and its association with schizophrenia.

RESULTS

The 22q11.2 DS syndrome has a variable phenotype associated with other genetic syndromes, birth defects in many tissues and organs, and a high rate of psychiatric disorders, particularly schizophrenia. Likewise, it has been identified in clinical populations with schizophrenia selected by the presence of common syndromic characteristics. FISH, qPCR and MLPA techniques, and recently, aCGH and NGS technologies, are being used to diagnose this microdeletion.

CONCLUSIONS

It is important in clinical practice to remember that people suffering the 22q11.2DS have a high genetic risk for developing schizophrenia, and it is considered that the simultaneous presence of this disease and 22q11.2DS represents a genetic subtype of schizophrenia. There are clear phenotypic criteria, molecular and cytogenetic methods to diagnose this group of patients, and to optimize a multidisciplinary approach in their monitoring.

Building collaboration in caring for people with schizophrenia

People with schizophrenia, who have disturbances in mood, thought processes and behavior, experience impairment in day-to-day functioning. Primary caregivers have tried to become involved in caring for persons with schizophrenia by coordination with community psychiatric nurses. Community psychiatric nurses have an important role to play in supporting families in this care, especially primary caregivers. The purpose of the present study was to explore the relationship between Thai community psychiatric nurses and primary caregivers of people with schizophrenia. Grounded theory methodology was used to examine the process with which community psychiatric nurses work together with primary caregivers. Purposive sampling and theoretical sampling were used. Data were collected from 34 informants, including 17 community psychiatric nurses and 17 primary caregivers through in-depth interviews, observation, and field notes. Data was analyzed using constant and comparative methods by Glaser (1978). The study revealed that building collaboration in the care of people with schizophrenia involved coordinating both community psychiatric nurses and primary caregivers in a process that consists of five major stages. In the first stage, community psychiatric nurses and primary caregivers used strategies to establish trust in each other before the next stage, which engaged their concerns and needs. Later, the stages of mutual preparation for caregiving, cooperating on patient care and monitoring outcomes were jointly employed in order to promote a healthy family life for patients. The study concludes by suggesting guidelines and giving insights into ways of helping primary caregivers and their patients with schizophrenia.

Neuregulin-1 signalling and antipsychotic treatment: potential therapeutic targets in a schizophrenia candidate signalling pathway

Identifying the signalling pathways underlying the pathophysiology of schizophrenia is an essential step in the rational development of new antipsychotic drugs for this devastating disease. Evidence from genetic, transgenic and post-mortem studies have strongly supported neuregulin-1 (NRG1)-ErbB4 signalling as a schizophrenia susceptibility pathway. NRG1-ErbB4 signalling plays crucial roles in regulating neurodevelopment and neurotransmission, with implications for the pathophysiology of schizophrenia. Post-mortem studies have demonstrated altered NRG1-ErbB4 signalling in the brain of schizophrenia patients. Antipsychotic drugs have different effects on NRG1-ErbB4 signalling depending on treatment duration. Abnormal behaviours relevant to certain features of schizophrenia are displayed in NRG1/ErbB4 knockout mice or those with NRG1/ErbB4 over-expression, some of these abnormalities can be improved by antipsychotic treatment. NRG1-ErbB4 signalling has extensive interactions with the GABAergic, glutamatergic and dopaminergic neurotransmission systems that are involved in the pathophysiology of schizophrenia. These interactions provide a number of targets for the development of new antipsychotic drugs. Furthermore, the key interaction points between NRG1-ErbB4 signalling and other schizophrenia susceptibility genes may also potentially provide specific targets for new antipsychotic drugs. In general, identification of these targets in NRG1-ErbB4 signalling and interacting pathways will provide unique opportunities for the development of new generation antipsychotics with specific efficacy and fewer side effects.

Comparison of quetiapine and risperidone in Chinese Han patients with schizophrenia: results of a single-blind, randomized study

OBJECTIVE

To evaluate the efficacy and safety of 750 mg/day quetiapine fumarate (Seroquel) in the treatment of Chinese Han patients with schizophrenia.

METHODS

In this 6-week, multicenter, randomized, rater single-blind study, a total of 119 patients with schizophrenia were randomly assigned to quetiapine (n = 60, 750 mg/day) or risperidone (n = 59, 4 mg/day). The efficacy was assessed by the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression-Change (CGI-C) and the Calgary Depression Scale for Schizophrenia (CDSS). Safety and tolerability assessments included treatment-emergent adverse events, laboratory tests and electrocardiograms.

RESULTS

The primary analysis demonstrated no significant difference between treatment in the two groups (quetiapine vs. risperidone: 31.9 ± 17.5 vs. 33.3 ± 17.3; P = 0.668). Improvements with both treatments were comparable for total PANSS, positive and negative subscores, general psychopathology subscales, and excitement and attack symptoms. Improvements in CGI-S were similar between treatment groups (P = 0.046). A more favorable trend was detected for quetiapine than risperidone in the reduction of CDSS scores from baseline, especially at week 1 (1.1 ± 2.2 vs. 0.3 ± 2.1, P < 0.050). The rate of extrapyramidal symptom (EPS) and hyperprolactinemia-related adverse events was significantly lower in the quetiapine group than the risperidone group (13.3% vs. 43.3%, P < 0.001). Dizziness and somnolence were more common in the quetiapine group than the risperidone group.

CONCLUSION

Quetiapine fumarate (750 mg/day) has broad clinical efficacy comparable to 4 mg/day risperidone. Dizziness was common in the quetiapine group (P = 0.029), but the rate of somnolence was similar between the two groups (P = 0.114). EPS and hyperprolactinemia rates were significantly higher with risperidone (P < 0.001). Key limitations of this study include small sample size, short treatment periods, and no increase to 6 mg/day for risperidone because of its safety profile.

Iron deficiency anemia in infancy exerts long-term effects on the tibialis anterior motor activity during sleep in childhood

OBJECTIVES

To explore the eventual connection between iron deficiency anemia (IDA) in infancy and altered leg movements during sleep in a 10-year follow-up study in children who did or did not have IDA in infancy.

SUBJECTS AND METHODS

Polysomnographic studies were performed in 32 10-year-old children (13 females and 19 males) who had IDA in infancy and 26 peers (10 females and 16 males) who were nonanemic controls. The time structure of their polysomnographically recorded leg movements (LM) was analyzed by means of an approach particularly able to consider their quantity, periodicity, and distribution during the night.

RESULTS

All LM indexes and those related to periodic LM during sleep (PLMS) were slightly higher in the former IDA group than in the control group, but not always significant. The Periodicity index during NREM sleep was higher and was reflected by a small but significant increase in PLMS separated by 10-50s intervals. PLMS index tended to be higher in former IDA children than in controls throughout the whole night.

CONCLUSION

The association between IDA in infancy, despite iron therapy, and PLMS in childhood could lead to new research in this area. Indeed, transient infantile IDA, a common nutritional problem among human infants, may turn out to be important for understanding the mechanisms of PLMS or restless legs syndrome, which are common in adulthood.

Relationships between occupational engagement and status of and satisfaction with sociodemographic factors in a group of people with schizophrenia

The present study is part of a larger project investigating occupational engagement and health in a group of people with schizophrenia. This study was aimed at extending this knowledge base with regard to occupational engagement and sociodemographic factors. Seventy-four outpatients participated in the study. The Profile of Occupational Engagement in People with Schizophrenia, the Lancashire Quality of Life Profile scale and a standardized questionnaire were used to gather data. Contrary to what was expected, occupational engagement was not associated with a certain type of schizophrenia, being younger or older, or gender. The results showed that a high level of occupational engagement was related to greater satisfaction with the participants' social and living situation, having a reliable alliance and a close friend, school-leaving age, living in a flat, and working or studying. Satisfaction with living independently, having had a recent experience of accomplishment, and working together explained 55% of the variance in occupational engagement. Occupational therapists should thus focus on and promote social engagement appropriate to the client's level of engagement, the client's opportunity and ability to work, his/her experience of accomplishment, and, most importantly, satisfaction with the home and living situation.

Creating a new whole: helping families of people with schizophrenia

Collaboration between psychiatric nurses and family members is considered an important part of caring for people with schizophrenia either in hospital or at home after discharge. Studies have demonstrated family involvement in terms of caring for patients who have been discharged early from hospital. An extensive review of the literature and related studies regarding nursing interventions have been done, but there have been limited studies on what psychiatric nurses actually do when working with the families of people with schizophrenia in Thailand. The purpose of the present study was to explore relationships between Thai psychiatric nurses and families in terms of administering nursing care to patients. Grounded theory methodology was used to examine the processes through which psychiatric nurses work with families. Data were collected by 16 psychiatric nurses through in-depth interviews, observations, and field notes. Data were analyzed using constant and comparative methods of other studies, which revealed the process by which nurses can create a new whole between families, patients, and Thai psychiatric nurses. The process consists of four major stages: establishing trust, strengthening connections, promoting readiness to care, and supporting family.

Epigenetics as a unifying principle in the aetiology of complex traits and diseases

Epigenetic modifications of DNA and histones might be crucial for understanding the molecular basis of complex phenotypes. One reason for this is that epigenetic factors are sometimes malleable and plastic enough to react to cues from the external and internal environments. Such induced epigenetic changes can be solidified and propagated during cell division, resulting in permanent maintenance of the acquired phenotype. In addition, the finding that there is partial epigenetic stability in somatic and germline cells allows insight into the molecular mechanisms of heritability. Epigenetics can provide a new framework for the search of aetiological factors in complex traits and diseases.

The maternal immune activation (MIA) model of schizophrenia produces pre-pulse inhibition (PPI) deficits in both juvenile and adult rats but these effects are not associated with maternal weight loss

The developmental onset of deficits in sensorimotor-gating was examined in the maternal immune activation (MIA) animal model of schizophrenia. Pre-pulse inhibition (PPI) deficits were evident in juvenile MIA rats. This parallels the sensorimotor-gating deficits observed in groups at high-risk of schizophrenia. PPI deficits were independent of maternal weight loss following the MIA manipulation, suggesting that this measure may not be a useful marker of treatment efficacy.

Genetic association studies of glutamate, GABA and related genes in schizophrenia and bipolar disorder: a decade of advance

Schizophrenia (SZ) and bipolar disorder (BD) are debilitating neurobehavioural disorders likely influenced by genetic and non-genetic factors and which can be seen as complex disorders of synaptic neurotransmission. The glutamatergic and GABAergic neurotransmission systems have been implicated in both diseases and we have reviewed extensive literature over a decade for evidence to support the association of glutamate and GABA genes in SZ and BD. Candidate-gene based population and family association studies have implicated some ionotrophic glutamate receptor genes (GRIN1, GRIN2A, GRIN2B and GRIK3), metabotropic glutamate receptor genes (such as GRM3), the G72/G30 locus and GABAergic genes (e.g. GAD1 and GABRB2) in both illnesses to varying degrees, but further replication studies are needed to validate these results. There is at present no consensus on specific single nucleotide polymorphisms or haplotypes associated with the particular candidate gene loci in these illnesses. The genetic architecture of glutamate systems in bipolar disorder need to be better studied in view of recent data suggesting an overlap in the genetic aetiology of SZ and BD. There is a pressing need to integrate research platforms in genomics, epistatic models, proteomics, metabolomics, neuroimaging technology and translational studies in order to allow a more integrated understanding of glutamate and GABAergic signalling processes and aberrations in SZ and BD as well as their relationships with clinical presentations and treatment progress over time.

Mutation screening of the glutamate cysteine ligase modifier (GCLM) gene in patients with schizophrenia

BACKGROUND

Experimental evidences show that glutathione and its rate-limiting synthesizing enzyme, the glutamate-cysteine ligase (GCL), are involved in the pathogenesis of schizophrenia. Furthermore, genetic association has been previously reported between two single nucleotide polymorphisms lying in noncoding regions of glutamate cysteine ligase modifier (GCLM) gene, which specifies for the modifier subunit of GCL and schizophrenia.

OBJECTIVE

We wanted to investigate the presence of GCLM true functional mutations, likely in linkage disequilibrium with the previously identified single nucleotide polymorphism alleles, in the same set of cases that allowed the detection of the original association signal.

METHODS

We screened all the coding regions of GCLM and their intronic flanking vicinities in 353 patients with schizophrenia by direct DNA sequencing.

RESULTS

Ten sequence variations were identified, five of which were not previously described. None of these DNA changes was within the GCLM coding sequence and in-silico analysis failed to indicate functional impairment induced by these variations. Furthermore, screening of normal controls and downstream statistical analyses revealed no significant relationship of any of these DNA variants with schizophrenia.

CONCLUSION

It is unlikely that functional mutations in the GCLM gene could play a major role in genetic predisposition to schizophrenia and further studies will be required to assess its etiological function in the disease.

Periodic leg movements during sleep and periodic limb movement disorder in patients presenting with unexplained insomnia

OBJECTIVE

The aim of this study was to evaluate quantitatively the presence and the characteristics of periodic leg movements during sleep (PLMS) in a group of consecutive patients presenting with daytime impairment related to insomnia of unknown etiology and whose polysomnographic features differ from those of healthy individuals only for a significantly increased arousal index in NREM sleep.

METHODS

We recruited 20 consecutive adult patients with insomnia according to the ICSD-2 criteria, 20 patients with RLS, and 12 age-matched normal controls. The time structure of their polysomnographically recorded leg movements during sleep was analyzed by means of an approach particularly able to consider their periodicity.

RESULTS

A subgroup of 12 patients with a relatively high number of periodic LM activity was detected with a statistically based approach using two indexes: total LM index and Periodicity index. This subgroup had high PLMS index, Periodicity index was also high and PLMS showed a progressive decrease during the night, being highest in the first hours of sleep. The characteristics of PLMS were identical within this insomnia subgroup and RLS patients.

CONCLUSIONS

PLMS was a common finding in our patients with insomnia and a detailed analysis of their periodicity revealed that a subgroup of these patients had to be finally diagnosed with Periodic Limb Movement Disorder.

SIGNIFICANCE

Polysomnography with the subsequent analysis of PLMS periodicity is able to differentiate between insomnia patient subgroups.

A protein interaction based model for schizophrenia study

Background

Schizophrenia is a complex disease with multiple factors contributing to its pathogenesis. In addition to environmental factors, genetic factors may also increase susceptibility. In other words, schizophrenia is a highly heritable disease. Some candidate genes have been deduced on the basis of their known function with others found on the basis of chromosomal location. Individuals with multiple candidate genes may have increased risk. However it is not clear what kind of gene combinations may produce the disease phenotype. Their collective effect remains to be studied.

Results

Most pathways except metabolic pathways are rich in protein-protein interactions (PPIs). Thus, the PPI network contains pathway information, even though the upstream-downstream relation of PPI is yet to be explored. Here we have constructed a PPI sub-network by extracting the nearest neighbour of the 36 reported candidate genes described in the literature. Although these candidate genes were discovered by different approaches, most of the proteins formed a cluster. Two major protein interaction modules were identified on the basis of the pairwise distance among the proteins in this sub-network. The large and small clusters might play roles in synaptic transmission and signal transduction, respectively, based on gene ontology annotation. The protein interactions in the synaptic transmission cluster were used to explain the interaction between the NRG1 and CACNG2 genes, which was found by both linkage and association studies. This working hypothesis is supported by the co-expression analysis based on public microarray gene expression.

Conclusion

On the basis of the protein interaction network, it appears that the NRG1-triggered NMDAR protein internalization and the CACNG2 mediated AMPA receptor recruiting may act together in the glutamatergic signalling process. Since both the NMDA and AMPA receptors are calcium channels, this process may regulate the influx of Ca²⁺. Reducing the cation influx might be one of the disease mechanisms for schizophrenia. This PPI network analysis approach combined with the support from co-expression analysis may provide an efficient way to propose pathogenetic mechanisms for various highly heritable diseases.

Environmental studies of schizophrenia through the prism of epigenetics

Traditionally, etiological research of schizophrenia has been focused on elucidating predisposing genes and environmental risk factors. While numerous putative environmental hazards have been suggested, inconsistencies and methodological limitations of epidemiological studies have made it difficult to identify even a single exogenous cause of schizophrenia. Furthermore, there is increasing evidence that environmental risk factors may not play as much of a significant role in schizophrenia as previously suspected. In this article, we argue that molecular epigenetic studies can overcome the complexities of traditional epidemiological studies and may become a productive line of research in understanding the nongenetic mechanisms of schizophrenia.

What a tangled web we weave: ethical and legal implications of deception in recruitment

Deception in human subject research is neither uncommon nor prohibited. The use of deception in the recruitment phase of clinical research has received relatively little attention. Given that informed consent is foundational to human subject research, the practice of misrepresenting the study purpose in clinical research would seem to contradict one of the fundamental tenets of ethical human subjects research. Using the example of prodromal psychosis, this article the ethical and legal implications of deception in recruitment and the sufficiency of current guidance on the practice when the study involves a stigmatizing condition, the collection of genetic samples, or both. I conclude that when these two elements are present, deception should only be used when absolutely necessary and, if used, researchers should be required to debrief participants before the collection of genetic samples and give particular attention to minimizing risks of privacy breaches.

Immune activation during mid-gestation disrupts sensorimotor gating in rat offspring

Maternal immune activation (MIA) is a newly developed animal model of schizophrenia. It has recently been reported that when MIA is induced with the cytokine inducer polyinosinic-polycytidilic acid (poly I:C) rats do not show deficits in prepulse inhibition (PPI), a test that is often considered a validity benchmark. The aim of the current experiment was to determine whether doses of poly I:C that have previously been shown to induce the behavioural features of schizophrenia can disrupt PPI in rats. Pregnant rat dams were given a single injection of poly I:C (4.0 mg/kg) or a saline injection equivalent on gestational day 15. Acoustic startle reactivity, habituation of the startle response and PPI were assessed in juvenile (34-35 day) and adult (>56 day) offspring. Prenatal immune activation did not alter startle reactivity on startle-only or prepulse-only trials. Furthermore, there was no effect of MIA on habituation of the startle response. MIA does however disrupt PPI, as PPI was reduced significantly in adult MIA offspring, and a trend was observed in the juvenile animals. Our finding that prenatal poly I:C can disrupt PPI in MIA rats further validates this procedure as an animal model.

Positive selection within the Schizophrenia-associated GABA(A) receptor beta(2) gene

The gamma-aminobutyric acid type-A (GABA_A) receptor plays a major role in inhibitory neurotransmissions. Intronic SNPs and haplotypes in GABRB2, the gene for GABA_A receptor β₂ subunit, are associated with schizophrenia and correlated with the expression of two alternatively spliced β₂ isoforms. In the present study, using chimpanzee as an ancestral reference, high frequencies were observed for the derived (D) alleles of the four SNPs rs6556547, rs187269, rs1816071 and rs1816072 in GABRB2, suggesting the occurrence of positive selection for these derived alleles. Coalescence-based simulation showed that the population frequency spectra and the frequencies of H56, the haplotype having all four D alleles, significantly deviated from neutral-evolution expectation in various demographic models. Haplotypes containing the derived allele of rs1816072 displayed significantly less diversity compared to haplotypes containing its ancestral allele, further supporting positive selection. The variations in DD-genotype frequencies in five human populations provided a snapshot of the evolutionary history, which suggested that the positive selections of the D alleles are recent and likely ongoing. The divergence between the DD-genotype profiles of schizophrenic and control samples pointed to the schizophrenia-relevance of positive selections, with the schizophrenic samples showing weakened selections compared to the controls. These DD-genotypes were previously found to increase the expression of β₂, especially its long isoform. Electrophysiological analysis showed that this long β₂ isoform favored by the positive selections is more sensitive than the short isoform to the inhibition of GABA_A receptor function by energy depletion. These findings represent the first demonstration of positive selection in a schizophrenia-associated gene.

First night efficacy of pramipexole in restless legs syndrome and periodic leg movements

OBJECTIVE

Restless legs syndrome (RLS) seems to improve immediately after a single dose of dopamine-agonists (DA). The aim of the present study was to investigate the acute effects of a low standard dose of pramipexole in RLS drug-naïve patients.

METHODS

A single-blind placebo-controlled study in 32 consecutive idiopathic RLS de-novo patients was carried out. Patients who met the standard criteria for RLS, with a PLMS index greater than 10 as well as an RLS rating scale score greater than 20 underwent clinical and neurophysiological evaluation, hematological screening and two consecutive full-night polysomnographies. On the second night, all patients received 0.25mg of pramipexole or placebo at 9:00 p.m. Acute symptom response was assessed by a visual analogical scale (VAS).

RESULTS

Eighteen patients received pramipexole and 14 patients received placebo. Compared to placebo, the single low dose (0.25mg) of pramipexole significantly improved RLS symptoms (VAS: from 7.4+/-1.68 to 1.3+/-1.62, p<0.00001) and strongly reduced PLMS index (from 45.8+/-33.56 to 9.4+/-11.40, p<0.0002). A significant increase in the percentage of stage 2 non-rapid eye movement (NREM) sleep was also observed in the pramipexole group (from 38.7+/-10.50 to 50.6+/-12.13, p<0.02).

CONCLUSIONS

A low dose of pramipexole was effective in treatment-naïve patients with RLS from the first night of administration. These results support a direct involvement of the dopaminergic system in RLS pathogenesis and might have important implications for a possible future pramipexole administration on-demand, as well as for a pharmacological test to confirm diagnosis in clinically complex cases.

GABRB2 association with schizophrenia: commonalities and differences between ethnic groups and clinical subtypes

BACKGROUND

Single nucleotide polymorphisms (SNPs) and haplotypes in intron 8 of type A gamma-aminobutyric acid (GABA(A)) receptor beta2 subunit gene (GABRB2) were initially found to be associated with schizophrenia in Chinese. This finding was subjected to cross-validation in this study with Japanese (JP) and German Caucasian (GE) subjects.

METHODS

Single nucleotide polymorphisms discovery and genotyping were carried out through resequencing of a 1839 base pair (bp) region in GABRB2. Tagging SNPs (tSNPs) were selected based on linkage disequilibrium (LD), combinations of which were analyzed with Bonferroni correction and permutation for disease association. Random resampling was applied to generate size- and gender-balanced cases and control subjects.

RESULTS

Out of the 17 SNPs (9.2/kilobase [kb]) revealed, 6 were population-specific. Population variations in LD were observable, and at least two low LD points were identified in both populations. Although disease association at single SNP level was only shown in GE, strong association was demonstrated in both JP (p = .0002 - .0191) and GE (p = .0033 - .0410) subjects, centering on haplotypes containing rs1816072 and rs1816071. Among different clinical subtypes, the most significant association was exhibited by systematic schizophrenia.

CONCLUSIONS

Cross-population validation of GABRB2 association with schizophrenia has been obtained with JP and GE subjects, with the genotype-disease correlations being strongest in systematic schizophrenia, the most severe subtype of the disease.

Alteration of conditioned emotional response and conditioned taste aversion after neonatal ventral hippocampus lesions in rats

Sprague-Dawley rats were submitted to bilateral ventral hippocampus lesions 7 days after birth according to the Lipska and Weinberger's procedure for modeling schizophrenia. The aim of the present work was to better characterize their learning capacity. A double latent inhibition study was conducted using respectively conditioned taste aversion and conditioned emotional response. In the background of this evaluation, locomotion under apomorphine and startle reactions, inhibited or not by prepulses, was also evaluated. Our experimental methods were the same as those used in previous studies from the laboratory which were found to be sensitive to pharmacological manipulations and shown by others to be unaffected by lesions of the ventral hippocampus carried out in adult rats. In contrast, neonatally lesioned rats, once adults (over 60 days old), were hyper-responsive to noise--i.e., the startle response to a 105 db(A) noise pulse was enhanced--and hyperactive under apomorphine (0.7 mg/kg). The prepulse inhibition properties of the startle remained unchanged. Lesioned rats showed a deficit but not a suppression of conditioning, similar in both tests, but latent inhibition was preserved. Such observations complement the already known memory deficit produced in this neurodevelopmental model of schizophrenia.

Heart rate and spectral EEG changes accompanying periodic and non-periodic leg movements during sleep

OBJECTIVE

To evaluate the changes in heart rate (HR) and EEG spectra accompanying periodic (PLM) and non-periodic leg movements (NPLM) during sleep in patients with restless legs syndrome (RLS).

METHODS

Sixteen patients with RLS underwent one polysomnographic night recording; leg movements (LMs) during sleep were detected and classified as PLM or NPLM; up to 10 PLM and NPLM were chosen from NREM and REM sleep, for each patient and for each type (mono- or bilateral). EEG spectral analysis and HR were evaluated for 20s preceding and 30s following the onset of each LM.

RESULTS

EEG activation preceded LMs, particularly in the delta band which increased before the other frequency bands, in NREM sleep but not in REM sleep for PLM, and in both stages for NPLM. A similar difference was seen between mono- and bilateral LMs.

CONCLUSIONS

Sleep EEG, HR, and leg motor activity seems to be modulated by a complex dynamically interacting system of cortical and subcortical mechanisms, which influence each other.

SIGNIFICANCE

Future studies on the clinical significance of leg motor events during sleep need to take into account events classifiable as "isolated" and to integrate the autonomic and EEG changes accompanying them.

Cognitive regeneration or enhancement: the ethical issues

The neurological and physiological basis of brain function and disease has been a significant focus of investigation throughout the history of medical research. Recent advances in understanding have led to the development of new treatments for diseases of the brain and defects of cognitive and behavioral function: pharmacological, cell-based and even gene therapy may all provide keys to cognitive regeneration. Such therapies, however, might be applied not only towards restoring brain function in the case of disease but to enhance cognitive function for healthy individuals. The concept of cognitive enhancement raises many ethical issues: whether brain-enhancing treatments should be developed and made available and to whom; and what potential consequences might arise? This paper explores some of the ethical arguments associated with cognitive enhancement and concludes that although the technology involved is as yet uncertain and issues of social equity remain to be addressed, the potential benefit of enhancing human brain function is clear.

Psychosis among "healthy" siblings of schizophrenia patients

BACKGROUND

Schizophrenia aggregates in families and accurate diagnoses are essential for genetic studies of schizophrenia. In this study, we investigated whether siblings of patients with schizophrenia can be identified as free of any psychotic disorder using only register information. We also analyzed the emergence of psychotic disorders among siblings of patients with schizophrenia during seven to eleven years of follow-up.

METHODS

A genetically homogenous population isolate in north-eastern Finland having 365 families with 446 patients with a diagnosis of schizophrenia was initially identified in 1991 using four nationwide registers. Between 1998 and 2002, 124 patients and 183 siblings in 110 families were contacted and interviewed using SCID-I, SCID-II and SANS. We also compared the frequency of mental disorders between siblings and a random population comparison group sample.

RESULTS

Thirty (16%) siblings received a diagnosis of psychotic disorder in the interview. 14 siblings had had psychotic symptoms already before 1991, while 16 developed psychotic symptoms during the follow-up. Over half of the siblings (n = 99, 54%) had a lifetime diagnosis of any mental disorder in the interview.

CONCLUSION

Register information cannot be used to exclude psychotic disorders among siblings of patients with schizophrenia. The high rate of emergence of new psychotic disorders among initially healthy siblings should be taken into account in genetic analysis.