Schizophrenia

Prevalence of metabolic syndrome among patients with schizophrenia in Palestine

BACKGROUND

Metabolic syndrome (MS) is a cluster of the most dangerous cardiac risk factors and is associated with high mortality. Ethnic differences in metabolic syndrome (MS) criteria and prevalence rates have been reported. The purpose of this study was to investigate the MS prevalence among patients with schizophrenia in Palestine.

METHODS

We recruited 250 patients with schizophrenia from 4 psychiatric primary healthcare centers in Northern Palestine. The MS prevalence was assessed based on National Cholesterol Education Program Adult Treatment Panel III Adapted criteria.

RESULTS

The overall MS prevalence was 43.6%, with 39% in male and 55.9% in female patients. On average, the study patients had 2.3 ± 1.3 metabolic abnormalities. Univariate analysis showed that MS was significantly higher with older age, female gender, longer duration of the illness, smoking, abdominal obesity, high systolic and diastolic blood pressure, high triglycerides, low HDL-C, and high fasting plasma glucose. Multiple logistic regression analysis showed that only systolic blood pressure, high triglycerides, high fasting plasma glucose, and low HDL-C were significant predictors of MS in schizophrenic patients.

CONCLUSIONS

MS is common among Arab patients with schizophrenia. Patients with schizophrenia should receive regular monitoring and adequate treatment of cardio-metabolic risk factors.

Assessing clinical and functional outcomes in a gene-environment interaction study in first episode of psychosis (PEPs)

The PEPs study is a multicenter, naturalistic, prospective, longitudinal study designed to evaluate clinical, neuropsychological, neuroimaging, biochemical, environmental and pharmacogenetic variables in a sample of nearly 350 first episode of psychosis patients and 250 healthy controls. The PEPs project was conducted in Spain from January 2009 to December 2011. This article describes the rationale for the measurement approach adopted, providing an overview of the selected clinical and functional measures. The main objectives are: a) the thorough clinical and neurocognitive characterization of a sample of first episodes of psychosis, and b) the study of the interactions between the genetic and environmental variables selected to predict clinical and brain structural outcomes, and to determine the relationship of genetic polymorphisms involved in the pharmacokinetics and pharmacodynamics, and the responses and adverse effects of treatment.

Neural basis of autobiographical memory retrieval in schizophrenia

BACKGROUND

Autobiographical memory retrieval is impaired in schizophrenia.

AIMS

To determine the neural basis of this impairment.

METHOD

Thirteen patients with schizophrenia and 14 healthy controls performed an autobiographical memory retrieval task based on cue words during functional magnetic resonance imaging. Patients were selected on the basis of their ability to perform the task and all participants received training.

RESULTS

Although patients and controls activated a similar brain network during autobiographical memory retrieval, patients displayed decreased activation in several of these regions, including the anterior cingulate cortex, left lateral prefrontal cortex, right cerebellum and ventral tegmental area (k≥10, P<0.001, uncorrected). In addition, activation of the caudate nuclei was negatively correlated with retrieval performance in controls but positively correlated with performance in patients.

CONCLUSIONS

The autobiographical memory retrieval brain network is impaired in schizophrenia. Patients with schizophrenia display decreased activation of the cognitive control network during retrieval, possibly due to aberrant functioning of the dorsal striatum.

Cannabis, a complex plant: different compounds and different effects on individuals

Cannabis is a complex plant, with major compounds such as delta-9-tetrahydrocannabinol and cannabidiol, which have opposing effects. The discovery of its compounds has led to the further discovery of an important neurotransmitter system called the endocannabinoid system. This system is widely distributed in the brain and in the body, and is considered to be responsible for numerous significant functions. There has been a recent and consistent worldwide increase in cannabis potency, with increasing associated health concerns. A number of epidemiological research projects have shown links between dose-related cannabis use and an increased risk of development of an enduring psychotic illness. However, it is also known that not everyone who uses cannabis is affected adversely in the same way. What makes someone more susceptible to its negative effects is not yet known, however there are some emerging vulnerability factors, ranging from certain genes to personality characteristics. In this article we first provide an overview of the biochemical basis of cannabis research by examining the different effects of the two main compounds of the plant and the endocannabinoid system, and then go on to review available information on the possible factors explaining variation of its effects upon different individuals.

Flupenthixol versus placebo for schizophrenia

BACKGROUND

Flupenthixol, first made available in the UK in 1965, has been used as a treatment for schizophrenia for decades.

OBJECTIVES

To evaluate the absolute clinical effects of flupenthixol for schizophrenia in comparison with placebo.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group Trials Register (August 2011), inspected references of all included or excluded studies for further trials, and contacted authors of trials for additional information.

SELECTION CRITERIA

All randomised controlled trials (RCTs) that compared flupenthixol with placebo for adults with schizophrenia or related disorders by any means of diagnosis. Primary outcomes of interest were clinically important change in global state, mental state and behaviour, and adverse effects.

DATA COLLECTION AND ANALYSIS

We extracted data from the one included study, discussed any disagreement, documented decisions and contacted the authors of the included study for further information. We analysed binary outcomes using a standard estimation of the risk ratio (RR) and its 95% confidence intervals (CI). For homogenous data we used a fixed-effect model. For rare events we analysed dichotomous data using Peto Odds ratio (OR), again with 95% CIs.

MAIN RESULTS

We could include only one small (n = 45) study of moderate quality. When the active α-flupenthixol was compared with the inactive placebo or β-flupenthixol groups combined, fewer people in the active treatment group needed additional antipsychotic medication by around four weeks for deterioration in their general state (n = 45, OR 0.19 CI 0.05 to 0.71). There was no clear difference in social functioning at one year (n = 45, RR 1.33 CI 0.91 to 1.96). We found no clear data on mental state and behaviour, adverse effects, service use, satisfaction with treatment or costs.

AUTHORS' CONCLUSIONS

We were surprised that this well-established drug had so few data from trials investigating its absolute effects. We think this is unlikely to be rectified some 50 years after its launch and know that this would not happen today. However, even though data are very limited, flupenthixol may well be worthy of careful investigation - partly to ensure that this inexpensive active drug is not forgotten.

NMDA antagonist ketamine reduces task selectivity in macaque dorsolateral prefrontal neurons and impairs performance of randomly interleaved prosaccades and antisaccades

Ketamine, an NMDA receptor antagonist, has been shown to induce behavioral abnormalities in humans that mimic the positive, negative, and most importantly cognitive deficits observed in schizophrenia. Similar cognitive deficits have been observed in nonhuman primates after a subanesthetic dose of ketamine, including an impairment in their ability to perform the antisaccade task, which requires the suppression of a prosaccade toward a flashed stimulus and the generation of a saccade in the opposite direction. The neural basis underlying these cognitive impairments remains unknown. Here, we recorded single-neuron activity in the lateral prefrontal cortex of macaque monkeys before and after the administration of subanesthetic doses of ketamine during the performance of randomly interleaved prosaccade and antisaccade trials. Ketamine impeded the monkeys' ability to maintain and apply the correct task rule and increased reaction times of prosaccades and antisaccades. These behavioral changes were associated with an overall increase in activity of PFC neurons and a reduction in their task selectivity. Our results suggest that the mechanism underlying ketamine-induced cognitive abnormalities may be the nonspecific increase in PFC activity and the associated reduction of task selectivity.

A preclinical assessment of d.l-govadine as a potential antipsychotic and cognitive enhancer

Tetrahydroprotoberberines (THPBs) are compounds derived from traditional Chinese medicine and increasing preclinical evidence suggests efficacy in treatment of a wide range of symptoms observed in schizophrenia. A receptor-binding profile of the THPB, d.l-govadine (d.l-Gov), reveals high affinity for dopamine and noradrenaline receptors, efficacy as a D2 receptor antagonist, brain penetrance in the 10-300 ng/g range, and thus motivated an assessment of the antipsychotic and pro-cognitive properties of this compound in the rat. Increased dopamine efflux in the prefrontal cortex and nucleus accumbens, measured by microdialysis, is observed following subcutaneous injection of the drug. d.l-Gov inhibits both conditioned avoidance responding (CAR) and amphetamine-induced locomotion (AIL) at lower doses than clozapine (CAR ED50: d.l-Gov 0.72 vs. clozapine 7.70 mg/kg; AIL ED50: d.l-Gov 1.70 vs. clozapine 4.27 mg/kg). Catalepsy is not detectable at low biologically relevant doses, but is observed at higher doses. Consistent with previous reports, acute d-amphetamine disrupts latent inhibition (LI) while a novel finding of enhanced LI is observed in sensitized animals. Treatment with d.l-Gov prior to conditioned stimulus (CS) pre-exposure restores LI to levels observed in controls in both sensitized animals and those treated acutely with d-amphetamine. Finally, possible pro-cognitive properties of d.l-Gov are assessed with the spatial delayed win-shift task. Subcutaneous injection of 1.0 mg/kg d.l-Gov failed to affect errors at a 30-min delay, but decreased errors observed at a 12-h delay. Collectively, these data provide the first evidence that d.l-Gov may have antipsychotic properties in conjunction with pro-cognitive effects, lending further support to the hypothesis that THPBs are a class of compounds which merit serious consideration as novel treatments for schizophrenia.

Multimodal functional and structural imaging investigations in psychosis research

Substantial pathophysiological questions about the relationship of brain pathologies in psychosis can only be answered by multimodal neuroimaging approaches combining different imaging modalities such as structural MRI (sMRI), functional MRI (fMRI), diffusion tensor imaging (DTI), positron emission tomography (PET) and magnetic-resonance spectroscopy. In particular, the multimodal imaging approach has the potential to shed light on the neuronal mechanisms underlying the major brain structural and functional pathophysiological features of schizophrenia and high-risk states such as prefronto-temporal gray matter reduction, altered higher-order cognitive processing, or disturbed dopaminergic and glutamatergic neurotransmission. In recent years, valuable new findings have been revealed in these fields by multimodal imaging studies mostly reflecting a direct and aligned correlation of brain pathologies in psychosis. However, the amount of multimodal studies is still limited, and further efforts have to be made to consolidate previous findings and to extend the scope to other pathophysiological parameters contributing to the pathogenesis of psychosis. Here, investigating the genetic foundations of brain pathology relationships is a major challenge for future multimodal imaging applications in psychosis research.

Efficacy and metabolic influence of paliperidone ER, aripiprazole and ziprasidone to patients with first-episode schizophrenia through 52 weeks follow-up in China

BACKGROUND

There are no direct comparisons of paliperidone extended-release (ER), aripiprazole and ziprasidone in efficacy and metabolic influence in patients with first-episode schizophrenia.

OBJECTIVE

The present study examined the efficacy and metabolic influence of paliperidone ER, aripiprazole and ziprasidone in patients with first-episode schizophrenia in China.

METHODS

Subjects were recruited from outpatient and 254 patients entered the trial. These patients received treatment randomly with paliperidone ER, aripiprazole and ziprasidone and were assessed at baseline, 13, 26 and 52 weeks, respectively with Positive and Negative Syndrome Scale (PANSS), 7-item Clinical Global Impressions-Severity (CGI-S), anthropometric (weight, body mass index and waist circumference) and metabolic (fasting blood glucose, HbA1c, cholesterol, high density lipoproteins (HDL), low density lipoproteins and triglycerides) measures.

RESULTS

A total of 203 patients completed the trial. Paliperidone group had significant greater reduction in PANSS than aripiprazole group and ziprasidone group from 13 weeks, although the a reduction in PANSS of each group was more than 20%. There was no difference in CGI-S among the three groups, and all three groups had a significant reduction from baseline in CGI-S. Aripiprazole group increased in weight and body mass index despite no statistical change in waist circumference. Other two groups showed no changes in anthropometric measure. At the end of the study, two glucose metabolic indices (fasting blood glucose and HbA1c) of aripiprazole group were significantly higher than that of baseline. In lipid metabolism, aripiprazole group reduced triglycerides significantly and had no changes in other indices. Paliperidone group reduced HDL and increased triglycerides despite no changes in glucose metabolism. Ziprasidone group also had no significant changes in glucose metabolism, but reduced cholesterol, low density lipoproteins and increased HDL. Furthermore, 22 subjects in three groups reached the diagnostic criteria of metabolic syndrome.

CONCLUSIONS

Paliperidone ER, aripiprazole and ziprasidone are effective in treating first-episode schizophrenia, and the ranking of efficacy from high to low is paliperidone ER > aripiprazole > ziprasidone. Paliperidone ER can impair lipid metabolism potentially but had no influence on glucose metabolism. Aripiprazole can damage glucose metabolism and has little influence on lipid metabolism. Ziprasidone is considered an atypical antipsychotic with no evidence of harm to glucose and lipid metabolism.

Societal participation: examining the impact of a rehabilitation approach for young people with schizophrenia

This paper is based on research that focuses on the impact of a rehabilitation approach with respect to 99 young people diagnosed with schizophrenia in a Dutch mental health facility. The approach focused on societal participation goals. Nurses and social workers play a key role in such treatment. The research focused on developmental trajectories and showed significant improvement with respect to societal participation levels. Impairment scores remained stable. The results indicate that rehabilitation counselling by nurses and social workers, in addition to medication and psychosocial treatment and integrated in a multidisciplinary team, can make a difference in a patient's societal participation.

Inhibition of the cortex using transcranial magnetic stimulation in psychiatric populations: current and future directions

Several lines of evidence suggest that deficits in γ-aminobutyric acid (GABA) inhibitory neurotransmission are implicated in the pathophysiology of schizophrenia, bipolar disorder, major depressive disorder and obsessive-compulsive disorder. Cortical inhibition refers to a neurophysiological process, whereby GABA inhibitory interneurons selectively attenuate pyramidal neurons. Transcranial magnetic stimulation (TMS) represents a noninvasive technique to measure cortical inhibition, excitability and plasticity in the cortex. These measures were traditionally specific to the motor cortex, which is an important limitation when nonmotor neurophysiological processes are of primary interest. Recently, TMS has been combined with electro encephalography (EEG) to derive such measurements directly from the cortex. This review focuses on neurophysiological studies related to inhibitory and excitatory TMS paradigms, linking dysfunctional GABAergic neurotransmission to disease states. We review evidence that suggests cortical inhibition deficits among psychiatric populations and demonstrate how each disorder has a specific neurophysiological response to treatment. We conclude by discussing the future directions of TMS combined with EEG, demonstrating the potential to identify biological markers of neuropsychiatric disorders.

Preclinical (1)H-MRS neurochemical profiling in neurological and psychiatric disorders

The ongoing development of animal models of neurological and psychiatric disorders in combination with the development of advanced nuclear magnetic resonance (NMR) techniques and instrumentation has led to increased use of in vivo proton NMR spectroscopy ((1)H-MRS) for neurochemical analyses. (1)H-MRS is one of only a few analytical methods that can assay in vivo and longitudinal neurochemical changes associated with neurological and psychiatric diseases, with the added advantage of being a technique that can be utilized in both preclinical and clinical studies. In this review, recent progress in the use of (1)H-MRS to investigate animal models of neurological and psychiatric disorders is summarized with examples from the literature and our own work.

Involvement of the primate specific gene G72 in schizophrenia: From genetic studies to pathomechanisms

Schizophrenia is a human mental disorder that affects an individual's thoughts, perception, affect and behavior, which is caused by a complex interaction of genetic and environmental factors. Genetic studies have implicated the evolutionary novel, anthropoid primate-specific gene locus G72/G30 in the etiology of schizophrenia and other psychiatric disorders. This gene encodes the protein LG72, which has been discussed as a modulator of the peroxisomal enzyme d-amino-acid-oxidase (DAO), or, alternatively as a mitochondrial protein. Recently, G72 transgenic (G72Tg) mice were generated that express the protein throughout the brain. These mice show several behavioral deficits that are related to schizophrenia. Further, G72Tg mice have a reduced activity of mitochondrial complex I, with a concomitantly increased production of reactive oxygen species, as well as deficits in short-term plasticity. Results from these studies demonstrate that expression of the human G72/G30 gene locus in mice produces behavioral phenotypes that are relevant to schizophrenia. They implicate LG72-induced mitochondrial and synaptic defects as a possible pathomechanism of this disease.

[Trauma and psychosis--part 2. On the association of early childhood maltreatment and risk of psychosis in general population]

Any association of early childhood maltreatment and later risk of psychosis may be favourably investigated by epidemiological studies in the general population. Primary outcome variable in these studies is the prevalence of subclinical psychotic symptoms (hallucinations, delusions) in early trauma-exposed groups compared to control groups without any significant trauma in childhood. A systematic literature search underlines a significant association of early childhood trauma and later non-clinical psychotic symptoms in representative samples of the general population both during childhood, adolescence and adulthood. Important questions deal with the issues, which psychological, psychosocial and neurobiological mechanisms may mediate the risk of early trauma in respect of later psychotic symptoms on the one side, and which factors may determine the transition from non-clinical psychotic symptoms to major psychotic disorders cared for within mental health services. Both theoretical models and first data derived from empirical studies will be presented.

Cotinine: Beyond that Expected, More than a Biomarker of Tobacco Consumption

A greater incidence of tobacco consumption occurs among individuals with psychiatric conditions including post-traumatic stress disorder (PTSD), bipolar disorder, major depression, and schizophrenia, compared with the general population. Even when still controversial, it has been postulated that smoking is a form of self-medication that reduces psychiatric symptoms among individuals with these disorders. To better understand the component(s) of tobacco-inducing smoking behavior, greater attention has been directed toward nicotine. However, in recent years, new evidence has shown that cotinine, the main metabolite of nicotine, exhibits beneficial effects over psychiatric symptoms and may therefore promote smoking within this population. Some of the behavioral effects of cotinine compared to nicotine are discussed here. Cotinine, which accumulates in the body as a result of tobacco exposure, crosses the blood-brain barrier and has different pharmacological properties compared with nicotine. Cotinine has a longer plasma half-life than nicotine and showed no addictive or cardiovascular effects in humans. In addition, at the preclinical level, cotinine facilitated the extinction of fear memory and anxiety after fear conditioning, improved working memory in a mouse model of Alzheimer’s disease (AD) and in a monkey model of schizophrenia. Altogether, the new evidence suggests that the pharmacological and behavioral effects of cotinine may play a key role in promoting tobacco smoking in individuals that suffer from psychiatric conditions and represents a new potential therapeutic agent against psychiatric conditions such as AD and PTSD.

Association of MB-COMT polymorphisms with schizophrenia-susceptibility and symptom severity in an African cohort

The catechol-O-methyltransferase (COMT) gene is an attractive schizophrenia candidate gene, encoding a catabolic dopamine enzyme. The enzyme exists as two distinct isoforms, with the membrane bound enzyme (i.e. MB-COMT) being predominantly expressed in the brain. Since African populations remain underrepresented in genetic/genomic research, we performed an association study to determine whether MB-COMT genetic variants are associated with schizophrenia-susceptibility and symptom severity in the South African Xhosa population. Fourteen candidate polymorphisms were selected by means of a literature search and in silico analyses and were subsequently genotyped in a cohort of 238 Xhosa schizophrenia patients and 240 healthy Xhosa controls. Genetic association was tested with schizophrenia-susceptibility as well as symptom severity within the patient group. Polymorphisms of interest were also analysed using functional assays. Two SNPs, rs2020917 (OR=0.54, 95% CI 0.37-0.79; P=0.0011) and rs737865 (OR=0.52, 95% CI 0.36-0.74; P=0.0002), in the P2 promoter region were significantly associated with schizophrenia as well as an increase (increase=11.2%, 95% CI 3.7%-19.2%; P=0.0031) in reporter gene expression. The minor alleles of these SNPs were underrepresented in the schizophrenia cohort, indicating a possible protective effect. The P2 region also formed part of a haplotype found to be associated with the severity of the negative symptoms of the disorder. The data generated by this study indicate that genetic variation of MB-COMT could be associated with schizophrenia and negative symptom severity in the Xhosa population and may therefore be one of the genomic loci contributing towards the disorder in the South African community. Future large-scale studies in other African schizophrenia populations are required to further elucidate the significance of these findings.

Neuropathology markers and pathways associated with molecular targets for antipsychotic drugs in postmortem brain tissues: exploration of drug targets through the Stanley Neuropathology Integrative Database

The atypical antipsychotics bind multiple receptor targets, including dopamine D₂ receptors (DRD2), 5-HT₂ receptors (HTR2A), α-2 adrenergic receptors (ADRA2A), and muscarinic receptors (CHRM1/4). Deficits in antipsychotic targets, their associated pathways, and the causal relationships between the various targets were explored using the Stanley Neuropathology Consortium Integrative Database (SNCID; http://sncid.stanleyresearch.org) and the Network Edge Orienting (NEO) software. There were brain region-specific deficits in the level of the antipsychotic targets, and the level of each target correlated with the mRNA level of the neurotrophic factor BDNF. While myelination was a common process correlated with both DRD2 mRNA levels and ADRA2A activity in the frontal cortex, metabolic processes were specifically correlated with DRD2 mRNA. Immune and inflammatory responses and apoptosis pathways were correlated with group II metabotropic glutamate receptors (GRM2), which are a target for the development of the next-generation antipsychotics. The NEO analysis revealed that HTR2A and GRM2 are likely to regulate BDNF levels in the hippocampus and frontal cortex, respectively, whereas DRD2 and ADRA2A activity are likely to be regulated by BDNF in the frontal cortex. BDNF may play an important role in mechanisms of action of the current antipsychotics and the next-generation antipsychotics that target GRM2. However, this data-mining approach indicates that the next-generation antipsychotics are likely to work through pathways that are distinct from those through which the current antipsychotics work. Exploratory analyses such as these may initiate future hypothesis-driven studies to reveal the mechanisms of action underlying the efficacy and side-effects of the antipsychotics.

De novo mutations in neurological and psychiatric disorders: effects, diagnosis and prevention

Neurological and psychiatric disorders account for a considerable proportion of the global disease burden. Although there is a high heritability and a significant genetic component in these disorders, the genetic cause of most cases has yet to be identified. Advances in DNA sequencing allowing the analysis of the whole human genome in a single experiment have led to an acceleration of the discovery of the genetic factors associated with human disease. Recent studies using these platforms have highlighted the important role of de novo mutations in neurological and psychiatric disorders. These findings have opened new avenues into the understanding of genetic disease mechanisms. These discoveries, combined with the increasing ease with which we can sequence the human genome, have important implications for diagnosis, prevention and treatment. Here, we present an overview of the recent discovery of de novo mutations using key examples of neurological and psychiatric disorders. We also discuss the impact of technological developments on diagnosis and prevention.

The schizophrenia-associated Kv11.1-3.1 isoform results in reduced current accumulation during repetitive brief depolarizations

Recent genome wide association studies identified a brain and primate specific isoform of a voltage-gated potassium channel, referred to as Kv11.1-3.1, which is significantly associated with schizophrenia. The 3.1 isoform replaces the first 102 amino acids of the most abundant isoform (referred to as Kv11.1-1A) with six unique amino acids. Here we show that the Kv11.1-3.1 isoform has faster rates of channel deactivation but a slowing of the rates of inactivation compared to the Kv11.1-1A isoform. The Kv11.1-3.1 isoform also has a significant depolarizing shift in the voltage-dependence of steady-state inactivation. The consequence of the altered gating kinetics is that there is lower current accumulation for Kv11.1-3.1 expressing cells during repetitive action potential firing compared to Kv11.1-1A expressing cells, which in turn will result in longer lasting trains of action potentials. Increased expression of Kv11.1-3.1 channels in the brain of schizophrenia patients might therefore contribute to disorganized neuronal firing.

Dual control of dopamine synthesis and release by presynaptic and postsynaptic dopamine D2 receptors

Dysfunctions of dopaminergic homeostasis leading to either low or high dopamine (DA) levels are causally linked to Parkinson's disease, schizophrenia, and addiction. Major sites of DA synthesis are the mesencephalic neurons originating in the substantia nigra and ventral tegmental area; these structures send major projections to the dorsal striatum (DSt) and nucleus accumbens (NAcc), respectively. DA finely tunes its own synthesis and release by activating DA D2 receptors (D2R). To date, this critical D2R-dependent function was thought to be solely due to activation of D2Rs on dopaminergic neurons (D2 autoreceptors); instead, using site-specific D2R knock-out mice, we uncover that D2 heteroreceptors located on non-DAergic medium spiny neurons participate in the control of DA levels. This D2 heteroreceptor-mediated mechanism is more efficient in the DSt than in NAcc, indicating that D2R signaling differentially regulates mesolimbic- versus nigrostriatal-mediated functions. This study reveals previously unappreciated control of DA signaling, shedding new light on region-specific regulation of DA-mediated effects.

Schizophrenia genetics: putting all the pieces together

Schizophrenia is a major mental disorder characterized by a deep disruption of the thinking process and of emotional response. For many decades, genetics studies have yielded little success in identifying genetic factors responsible for the disease. However, with the recent breakthroughs in genome analysis technologies, the field of the genetics of schizophrenia has progressed a lot in the last years. Both common and rare variants have been successfully associated with the disease and a particular emphasis has been made on rare copy number variations. Recently, a new paradigm linking de novo mutations to the genetic mechanism of schizophrenia has been unravelled. The aim of this review is to discuss the most important genetic studies made in the field to give a general perspective of where to go in the future.

A systematic review of instruments to measure depressive symptoms in patients with schizophrenia

BACKGROUND

Depressive symptoms require accurate recognition and monitoring in clinical practice of patients with schizophrenia. Depression instruments developed for use in depressed patients may not discriminate depressive symptoms from negative psychotic symptoms.

OBJECTIVE

We reviewed depression instruments on their reliability and validity in patients with schizophrenia.

METHODOLOGY

A systematic literature search was carried out in three electronic databases. Psychometric properties were extracted for those instruments of which reliability, divergent, concurrent and predictive validity were reported in one or more publications.

RESULTS

Forty-eight publications described the reliability and validity of six depression instruments in patients with schizophrenia. The only self-report was the Beck Depression Inventory (BDI). The Brief Psychiatric Rating Scale-Depression subscale (BPRS-D), Positive and Negative Syndrome Scale-Depression subscale (PANSS-D), Hamilton Rating Scale for Depression (HAMD), Montgomery Asberg Depression Rating Scale (MADRS) and Calgary Depression Scale for Schizophrenia (CDSS) were clinician rated. All instruments were reliable for the measurement of depressive symptoms in patients with schizophrenia. The CDSS most accurately differentiated depressive symptoms from other symptoms of schizophrenia (divergent validity), correlated well with other depression instruments (concurrent validity), and was least likely to miss cases of depression or misdiagnose depression (predictive validity).

CONCLUSIONS

We would recommend to use the CDSS for the measurement of depressive symptoms in research and in daily clinical practice of patients with schizophrenia. A valid self-report instrument is to be developed for the use in clinical practice.

Psychosis Incident Cohort Outcome Study (PICOS). A multisite study of clinical, social and biological characteristics, patterns of care and predictors of outcome in first-episode psychosis. Background, methodology and overview of the patient sample

AIMS

This paper aims at providing an overview of the background, design and initial findings of Psychosis Incident Cohort Outcome Study (PICOS).

METHODS

PICOS is a large multi-site population-based study on first-episode psychosis (FEP) patients attending public mental health services in the Veneto region (Italy) over a 3-year period. PICOS has a naturalistic longitudinal design and it includes three different modules addressing, respectively, clinical and social variables, genetics and brain imaging. Its primary aims are to characterize FEP patients in terms of clinical, psychological and social presentation, and to investigate the relative weight of clinical, environmental and biological factors (i.e. genetics and brain structure/functioning) in predicting the outcome of FEP.

RESULTS

An in-depth description of the research methodology is given first. Details on recruitment phase and baseline and follow-up evaluations are then provided. Initial findings relating to patients' baseline assessments are also presented. Future planned analyses are outlined.

CONCLUSIONS

Both strengths and limitations of PICOS are discussed in the light of issues not addressed in the current literature on FEP. This study aims at making a substantial contribution to research on FEP patients. It is hoped that the research strategies adopted in PICOS will enhance the convergence of methodologies in ongoing and future studies on FEP.

Internet-based interventions for psychosis: a sneak-peek into the future

The Internet and mobile technologies are becoming ubiquitous. However, the potential of these technologies to support people with psychosis has been unexplored and the development of innovative e-based interventions is overdue. Research suggests the acceptability and effectiveness of such interventions in psychosis. Internet-based technologies have the potential to transform psychosis treatment by enhancing the accessibility of evidence-based interventions, fostering engagement with mental health services, and maintaining treatment benefits over the long term. This article reviews the current evidence on Internet-based interventions for psychosis, including potential benefits, risks, and future challenges. Recommendations are proposed for developing future online interventions for psychosis.

Antipsychotics, dopamine D₂ receptor occupancy and clinical improvement in schizophrenia: a meta-analysis

OBJECTIVE

Treatment of schizophrenia (SCZ) was revolutionized with the development of the antipsychotic medications. Although imaging studies have linked antipsychotic D₂ receptor occupancy and clinical response in SCZ, heterogeneity between cohorts and methods has made it challenging to generalize findings across studies. The main objective of this meta-analysis was to analyze the relationship between in vivo estimation of typical and atypical antipsychotic D₂ receptor occupancy and treatment response in SCZ.

METHODS

Using the keywords "dopamine D₂ receptor occupancy," "schizophrenia," "PET/SPECT" and "antipsychotics," and further refining our search to journal articles with information on % striatal D₂ occupancy and % change in clinical symptoms as indexed by either the BPRS or the PANSS, our final analysis consisted of 16 imaging studies (20 cohorts; N=206).

RESULTS

The first step of the meta-analysis confirmed the positive relationship between antipsychotic medication and clinical improvement in SCZ (ES=1.36; 95% CI: 1.13-1.60). The second step of our analysis revealed that when D₂ occupancy was limited to less than 80% in order to control for the appearance of extrapyramidal symptoms, high D₂ occupancy was correlated with reduction in clinical scores (r=0.4, p<0.001) for medications other than clozapine or quetiapine.

CONCLUSIONS

Our results suggest that D₂ occupancy is a contributing factor for the mechanism of antipsychotic effect in SCZ for some but not all antipsychotic medications.

Trajectories of change in self-reported psychotic-like experiences in childhood and adolescence

BACKGROUND

Psychotic-like experiences (PLEs) during adolescence are not uncommon and potentially represent a clinical and public health concern. A greater understanding of their aetiology and patterns of change over time is needed. We aimed to describe trajectories of PLEs during adolescence, and examine their association with characteristics earlier during development.

METHOD

This was a cohort study of 7387 adolescents from the ALSPAC birth cohort who completed self-reported questionnaires about PLEs at 4 time points over a five-year period (ages 11.5-16.5years). Association between childhood characteristics and latent class membership was examined.

RESULTS

The proportion of children reporting PLEs declined with age. Individuals within decreasing (1.7%), intermittent (16.8%), and persistent (0.9%) PLEs trajectories were more likely to come from adverse backgrounds and have disturbed childhood development compared to the low PLE (80.6%) class. Persistent-class individuals scored highest on most measures though no measure clearly distinguished between persistent, intermittent and decreasing groups.

CONCLUSIONS

A number of early life characteristics and markers of childhood emotional and behavioural development are associated with trajectories of PLEs during adolescence. Despite the increase in cost and time required to collect data at repeated intervals, studies of trajectories are likely to have greater potential for predicting transition into clinical disorder at an earlier stage.

A Review of Brain-derived Neurotrophic Factor as a Candidate Biomarker in Schizophrenia

Brain-derived neurotrophic factor (BDNF), a neurotrophin known to be responsible for development, regeneration, survival and maintenance of neurons has been implicated in the pathophysiology of schizophrenia. This review seeks to complement previous reviews on biological roles of BDNF and summarizes evidence on the involvement of BDNF in the pathophysiology of schizophrenia with an emphasis on clinical relevance. The expressions of BDNF were altered in patients with schizophrenia and were found to be correlated with psychotic symptomatology. Antipsychotics appeared to have differential effects on expression of BDNF but did not restore BDNF expression of patients with schizophrenia to normal levels. In addition, evidence suggests that BDNF is involved in the major neurotransmitter systems and is associated with disruptions in brain structure, neurodevelopmental process, cognitive function, metabolic and immune systems commonly associated with schizophrenia. Besides that, BDNF has been demonstrated to be tightly regulated with estrogen which has also been previously implicated in schizophrenia. Evidence gathered in this review confirms the relevance of BDNF in the pathophysiology of schizophrenia and the potential utility of BDNF as a suitable biomarker for diagnostic and prognostic purposes for disease outcome and other co-morbidities. However, further investigations are warranted to examine the specificity of BDNF in schizophrenia compared to other neurodegenerative disorders and other neuropsychiatric illness. Longitudinal prospective studies will also be of added advantage for evaluation of prognostic utility of BDNF in schizophrenia.

MicroRNAs in learning, memory, and neurological diseases

MicroRNAs (miRNAs) represent a class of small regulatory noncoding RNAs ∼22 bp in length that mediate post-transcriptional silencing of gene expression via the recognition of specific sequences in target messenger (m)RNAs. The current body of literature suggests that miRNAs are fine-tuning regulators of gene expression profiles in a wide range of biological processes, from development to cancer. Many miRNAs are highly expressed in the adult nervous system in a spatially and temporally controlled manner in normal physiology, as well as in certain pathological conditions. These findings emphasize that gene regulation networks based on miRNA activities may be particularly important to brain function, and that perturbation of these networks may result in abnormal brain function. Indeed, miRNAs have been implicated in various aspects of dendrite remodeling and synaptic plasticity, as well as in experience-dependent adaptive changes of neural circuits in the postnatal developmental and adult brain. Recent advances in methods of next-generation sequencing, such as RNA-seq, offer the means to quantitatively evaluate the functions of miRNAs in a genome-wide manner in large cohorts of samples. These new technologies have already yielded valuable information and are expanding our understanding of miRNA-based mechanisms in higher-order brain processing, including learning and memory and cognition, as well as in neuropsychiatric disorders.

Heterogeneity and symptom structure of schizophrenia

Previous studies failed to identify a consistent factor structure of the BPRS-24 in schizophrenia. Our aims were to examine the fit of all previously published factor models and then to explore unobserved population heterogeneity and identify salient latent classes. Two hundred thirty-nine patients with ICD-10 schizophrenia admitted to a random sample of all Italian public and private acute inpatient units during an index period were administered the BPRS-24. Confirmatory factor analysis (CFA) was used to test all factor models derived in previous studies. Then, factor mixture analysis (FMA) with heteroscedastic components was carried out to explore unobserved population heterogeneity. No previously reported factor solution showed adequate fit in CFA. FMA indicated the presence of three heterogeneous groups and yielded a 5-factor solution (Depression, Positive Symptoms, Disorganization, Negative Symptoms, Activation). Group 1 was characterized by higher Disorganization, lower Activation, lower psychosocial functioning, greater lifetime number of admissions, more frequent history of compulsory admission. Group 2 displayed lower Disorganization. Group 3 showed higher Activation and more frequent history of recent self-harming behavior. Our finding that a reliable factor structure for the BPRS-24 could be obtained only after assuming population heterogeneity suggests that the difficulty in identifying a consistent factor structure may be ascribed to the clinical heterogeneity of schizophrenia. As compared with clinical subtypes, the psychopathological dimensions displayed much greater discriminatory power between groups identified by FMA. Though preliminary, our findings corroborate that a dimensional approach to psychopathology can facilitate the assessment of the clinical heterogeneity of schizophrenia.

Schizophrenia shows a unique metabolomics signature in plasma

Schizophrenia is a severe complex mental disorder affecting 0.5-1% of the world population. To date, diagnosis of the disease is mainly based on personal and thus subjective interviews. The underlying molecular mechanism of schizophrenia is poorly understood. Using targeted metabolomics we quantified and compared 103 metabolites in plasma samples from 216 healthy controls and 265 schizophrenic patients, including 52 cases that do not take antipsychotic medication. Compared with healthy controls, levels of five metabolites were found significantly altered in schizophrenic patients (P-values ranged from 2.9 × 10(-8) to 2.5 × 10(-4)) and in neuroleptics-free probands (P-values ranging between 0.006 and 0.03), respectively. These metabolites include four amino acids (arginine, glutamine, histidine and ornithine) and one lipid (PC ae C38:6) and are suggested as candidate biomarkers for schizophrenia. To explore the genetic susceptibility on the associated metabolic pathways, we constructed a molecular network connecting these five aberrant metabolites with 13 schizophrenia risk genes. Our result implicated aberrations in biosynthetic pathways linked to glutamine and arginine metabolism and associated signaling pathways as genetic risk factors, which may contribute to patho-mechanisms and memory deficits associated with schizophrenia. This study illustrated that the metabolic deviations detected in plasma may serve as potential biomarkers to aid diagnosis of schizophrenia.

Psychotic experience subtypes, poor mental health status and help-seeking behaviour in a community sample of young adults

BACKGROUND

Different subtypes of psychotic experiences (PEs) have been identified in clinical and non-clinical samples. Researchers have considered these PEs to either be variations of personality or expressions of vulnerability to psychotic disorder. This study aimed to determine which particular subtypes of PEs were more likely to be associated with poor mental health status and help-seeking behaviour in a non-clinical sample of young adults.

METHODS

The study was conducted on a community sample of 997 young adults. The prevalence of PEs and distress was measured using the community assessment of psychic experiences (CAPE), depressive and anxiety symptoms were measured using Beck depression inventory-II and Beck anxiety inventory, and general functioning was measured using the general health questionnaire-12. Factorial analysis of the CAPE positive dimension was conducted and correlations between factors and clinical variables were analysed.

RESULTS

Four PE subtypes were identified: perceptual abnormalities, persecutory ideas (PI), bizarre experiences, and magical thinking. At least one high frequency PI was endorsed by 60.8% (n = 606) of the sample and proved to be significantly associated both with poor mental health status and help-seeking behaviour.

CONCLUSION

PEs subtypes are differentially associated with various markers of poor mental health status. PI seem to have stronger psychopathological significance than other subtypes of PEs. Further longitudinal studies are required to extend these findings.

Phenotypic expression of schizotypal traits in an adolescent population

The main goal of the present study was to examine the influence of gender and age in the phenotypic expression of schizotypal traits in a community sample of adolescents. The sample was composed of a total of 1,618 participants, 776 (48%) males, with a mean age of 15.9 years (SD = 1.2). The ESQUIZO-Q: Oviedo Schizotypy Assessment Questionnaire was used for the assessment of schizotypal traits, a measure specifically developed for its use in adolescents. The results showed that gender and age were two sociodemographical variables that influenced the expression of schizotypal features. The males in the study obtained higher mean scores than the females in the Negative dimension (Physical and Social Anhedonia); however, the females obtained higher mean scores in Magical Thinking, Lack of Close Friends, and Social Disorganization. With regard to age, the younger adolescents had lower scores in Odd Thinking and Language, Lack of Close Friends, Excessive Social Anxiety, and Social Disorganization compared to the older adolescents. This differential pattern is similar to the one found in patients with schizophrenia and in nonclinical young adults, and these findings improve our understanding about the phenotypic expression of schizotypy during adolescence.

Psychometric properties of the Peters et al Delusions Inventory 21 in college students

Delusions show high prevalence in the general population and can be considered a risk marker for psychotic disorders. Although the assessment of these experiences has made considerable progress in recent years, there is still room for improvement in the measurement quality of the self-reports available for such assessment. The goal of the present work was to analyze the measurement quality of the Peters et al Delusions Inventory 21 (PDI-21) in Spanish college students. The final sample was made up of 660 participants (29.5% men) with a mean age of 20.3 years (SD, 2.6 years). The results revealed that a high percentage of the sample reported some symptom of paranoia. Analysis of the internal structure of the PDI-21 by means of exploratory factor analysis based on the tetrachoric correlation matrix yielded an essentially unidimensional solution. Cronbach α for the total score was .91. Scores on the PDI-21 correlated in a statistically significant fashion with trait and state anxiety and negative affect. These results provide new evidence of the validity of the PDI-21 and endorse its use as a measurement instrument for assessing the extended psychosis phenotype in nonclinical population.

Patients with functional psychoses show similar visual backward masking deficits

Recent genetic, behavioral, and clinical studies suggest that functional psychoses (schizophrenia, bipolar disorder, schizoaffective disorder), previously thought to be distinct from each other, may belong to one continuum. The shine-through masking paradigm is a potential endophenotype of schizophrenia with high sensitivity and specificity for discriminating between patients, their clinically unaffected relatives, and healthy controls. Hence, if schizophrenia, bipolar disorder and schizoaffective disorder belong to one common disease, strong masking deficits are expected to occur in all three diseases whereas no masking deficits are expected for abstinent alcoholic or depressive patients. Indeed, we found masking to be much stronger in psychotic patients compared to controls and to depressive patients and abstinent alcoholics, who performed on similar levels.

Discovery of tetrahydropyridopyrimidine phosphodiesterase 10A inhibitors for the treatment of schizophrenia

We describe the discovery of potent and orally bioavailable tetrahydropyridopyrimidine inhibitors of phosphodiesterase 10A by systematic optimization of a novel HTS lead. Lead compound THPP-1 exhibits nanomolar potencies, excellent pharmacokinetic properties, and a clean off-target profile. It displays in vivo target engagement as measured by increased rat striatal cGMP levels upon oral dosing. It shows dose-dependent efficacy in a key pharmacodynamic assay predictive of antipsychotic activity, the psychostimulant-induced rat hyperlocomotion assay. Further, THPP-1 displays significantly fewer preclinical adverse events in assays measuring prolactin secretion, catalepsy, and weight gain, in contrast to the typical and atypical antipsychotics haloperidol and olanzapine.

Progressive muscle relaxation in persons with schizophrenia: a systematic review of randomized controlled trials

Objective:

The aim of this systematic review was to assess the effectiveness of progressive muscle relaxation on psychological distress and anxiety symptoms and on response/remission for people with schizophrenia.

Methods:

Randomized controlled trials were considered if they investigated progressive muscle relaxation in patients with schizophrenia. EMBASE, PsycINFO, PubMed, ISI Web of Science, CINAHL, PEDro and Cochrane Library were searched. The selection of studies, data extraction and quality assessment were performed independently by two reviewers.

Results:

Three randomized controlled trials involving 146 patients met the inclusion criteria. Progressive muscle relaxation can acutely reduce state anxiety and psychological distress and improve subjective well-being. No studies investigated the evidence for progressive muscle relaxation as an add-on treatment for general psychopathology and for positive or negative symptoms. Also, no studies assessed the value of progressive muscle relaxation in longer-term treatment and for relapse prevention. There were no data to draw any conclusions about progressive muscle relaxation in comparison with other treatment modalities. None of the studies encountered adverse events. Dose-response relationships could not be determined.

Conclusion:

Progressive muscle relaxation might be a useful add-on treatment to reduce state anxiety and psychological distress and improve subjective well-being in persons with schizophrenia.

The possible role of the Akt signaling pathway in schizophrenia

Serine/threonine protein kinase v-akt murine thymoma viral oncogene homolog (Akt) is one of the survival kinases with multiple biological functions in the brain and throughout the body. Schizophrenia is one of the most devastating psychiatric disorders. Accumulating evidence has indicated the involvement of the Akt signaling pathway in the pathogenesis of this disorder. Genetic linkage and association studies have identified Akt-1 as a candidate susceptibility gene related for schizophrenia. The level of Akt-1 protein and its kinase activity decreased significantly both in white blood cells from schizophrenic patients and in postmortem brain tissue of schizophrenic patients. Consistent with these findings, alterations in the upstream and downstream pathways of Akt have also been found in many psychiatric disorders. Furthermore, both typical and atypical antipsychotic drugs modify the Akt signaling pathway in a variety of conditions relative to schizophrenia. In addition as a survival kinase, Akt participates in neurodevelopment, synaptic plasticity, protein synthesis and neurotransmission in the central nervous system. It is thought that reduced activity of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway could at least partially explain the cognitive impairment, synaptic morphologic abnormality, neuronal atrophy and dysfunction of neurotransmitter signaling in schizophrenia. In addition, reduced levels of Akt may increase the effects of risk factors on neurodevelopment, attenuate the effects of growth factors on neurodevelopment and reduce the response of patients to antipsychotic agents. More recently, the role of Akt signaling in the functions of schizophrenia susceptibility genes such as disrupted-in-schizophrenia 1 (DISC-1), neuregulin-1 (NRG-1) and dysbindin-1 has been reported. Thus, Akt deficiency may create a context permissive for the expression of risk-gene effects in neuronal morphology and function. This paper reviews the role of Akt in the pathophysiology of schizophrenia and as a potential therapeutic strategy targeting Akt.

[The long-term treatment of schizophrenia]

The long-term treatment of schizophrenia is one of the most challenging tasks for practicing physicians. The most pronounced difficulty arises from the deficient compliance due to the lack of insight. Thus the treatment of schizophrenia requires a multimodal approach, which always includes psychosocial interventions beside the pharmacological treatment. The antipsychotic medication means the cornerstone in the pharmacological treatment of schizophrenia within which an increasing role of the long-acting second-generation injections can be detected. The outcome of schizophrenia can be modified by adequately organized management strategies, which in turn can lead to better quality of life and social functioning. If patients are provided with timely initiated effective medication and rehabilitation, then enduring remission can be a realistically achievable goal for the patients.

Leptin and interleukin-6 alter the function of mesolimbic dopamine neurons in a rodent model of prenatal inflammation

Maternal inflammation during critical stages of gestation is thought to underlie the link between prenatal infection and several neurodevelopmental psychiatric disorders in the offspring, including schizophrenia. Increased activity of mesolimbic dopamine (DA) neurons, a hallmark of psychosis, is found in offspring of rodents exposed to a prenatal inflammatory challenge but it is unclear how this effect is elicited. Using an experimental model of localized aseptic inflammation with turpentine oil (TURP) we sought to establish whether circulating interleukin-6 (IL-6) and leptin play a role in the effects of prenatal inflammation on DA neurons. Both mediators are involved in the systemic inflammatory response to immunogens, with IL-6 mediating the early phase, followed by leptin in the late phase of the response. Maternal treatment with TURP at gestational day (GD) 15 enhanced the locomotor response to the DA indirect agonist, amphetamine (AMPH), increased the expression of tyrosine hydroxylase (TH), an enzyme involved in DA synthesis, DA levels and the expression of the post-synaptic protein spinophilin in the nucleus accumbens (NAcc) in the adult offspring. All of these alterations were totally abolished by co-treating the pregnant dams with a neutralizing IL-6 antiserum. Neutralization of maternal leptin prevented the enhanced behavioral sensitization and elevation of DA and spinophilin in the NAcc but spared other changes regulated by IL-6, such as increased NAcc TH levels and acute locomotor response to AMPH. Our results provide novel evidence to suggest that prenatal surges in both maternal circulating IL-6 and leptin contribute to the appearance of sensitized DA function in the adult offspring.

Hypothesis review: are clathrin-mediated endocytosis and clathrin-dependent membrane and protein trafficking core pathophysiological processes in schizophrenia and bipolar disorder?

Clathrin-mediated endocytosis (CME) is the best-characterized mechanism governing cellular membrane and protein trafficking. In this hypothesis review, we integrate recent evidence implicating CME and related cellular trafficking mechanisms in the pathophysiology of psychotic disorders such as schizophrenia and bipolar disorder. The evidence includes proteomic and genomic findings implicating proteins and genes of the clathrin interactome. Additionally, several important candidate genes for schizophrenia, such as dysbindin, are involved in processes closely linked to CME and membrane trafficking. We discuss that key aspects of psychosis neuropathology such as synaptic dysfunction, white matter changes and aberrant neurodevelopment are all influenced by clathrin-dependent processes, and that other cellular trafficking mechanisms previously linked to psychoses interact with the clathrin interactome in important ways. Furthermore, many antipsychotic drugs have been shown to affect clathrin-interacting proteins. We propose that the targeted pharmacological manipulation of the clathrin interactome may offer fruitful opportunities for novel treatments of schizophrenia.

G-protein-coupled receptors in adult neurogenesis

The importance of adult neurogenesis has only recently been accepted, resulting in a completely new field of investigation within stem cell biology. The regulation and functional significance of adult neurogenesis is currently an area of highly active research. G-protein-coupled receptors (GPCRs) have emerged as potential modulators of adult neurogenesis. GPCRs represent a class of proteins with significant clinical importance, because approximately 30% of all modern therapeutic treatments target these receptors. GPCRs bind to a large class of neurotransmitters and neuromodulators such as norepinephrine, dopamine, and serotonin. Besides their typical role in cellular communication, GPCRs are expressed on adult neural stem cells and their progenitors that relay specific signals to regulate the neurogenic process. This review summarizes the field of adult neurogenesis and its methods and specifies the roles of various GPCRs and their signal transduction pathways that are involved in the regulation of adult neural stem cells and their progenitors. Current evidence supporting adult neurogenesis as a model for self-repair in neuropathologic conditions, adult neural stem cell therapeutic strategies, and potential avenues for GPCR-based therapeutics are also discussed.

Schizophrenia, culture and neuropsychology: sensory deficits, language impairments and social functioning in Chinese-speaking schizophrenia patients

BACKGROUND

While 20% of schizophrenia patients worldwide speak tonal languages (e.g. Mandarin), studies are limited to Western-language patients. Western-language patients show tonal deficits that are related to impaired emotional processing of speech. However, language processing is minimally affected. In contrast, in Mandarin, syllables are voiced in one of four tones, with word meaning varying accordingly. We hypothesized that Mandarin-speaking schizophrenia patients would show impairments in underlying basic auditory processing that, unlike in Western groups, would relate to deficits in word recognition and social outcomes.

METHOD

Altogether, 22 Mandarin-speaking schizophrenia patients and 44 matched healthy participants were recruited from New York City. The auditory tasks were: (1) tone matching; (2) distorted tunes; (3) Chinese word discrimination; (4) Chinese word identification. Social outcomes were measured by marital status, employment and most recent employment status.

RESULTS

Patients showed deficits in tone-matching, distorted tunes, word discrimination and word identification versus controls (all p<0.0001). Impairments in tone-matching across groups correlated with both word identification (p<0.0001) and discrimination (p<0.0001). On social outcomes, tonally impaired patients had 'lower-status' jobs overall when compared with tonally intact patients (p<0.005) and controls (p<0.0001).

CONCLUSIONS

Our study is the first to investigate an interaction between neuropsychology and language among Mandarin-speaking schizophrenia patients. As predicted, patients were highly impaired in both tone and auditory word processing, with these two measures significantly correlated. Tonally impaired patients showed significantly worse employment-status function than tonally intact patients, suggesting a link between sensory impairment and employment status outcome. While neuropsychological deficits appear similar cross-culturally, their consequences may be language- and culture-dependent.

Yoga in schizophrenia: a systematic review of randomised controlled trials

OBJECTIVE

The objective of this systematic review was to assess the effectiveness of yoga as a complementary treatment on general psychopathology, positive and negative symptoms and health-related quality of life (HRQL) for people with schizophrenia.

METHOD

Randomised controlled trials (RCTs) were considered whether they investigated a yoga intervention in patients with schizophrenia. The selection of studies, data extraction and quality assessment were performed independently by two reviewers.

RESULTS

Only three RCTs met the inclusion criteria. Lower Positive and Negative Syndrome Scale (PANSS) total scores and subscale scores for positive and negative symptoms were obtained after yoga compared with exercise or waiting list control conditions. In the same way, the physical, psychological, social and environmental HRQL as measured with the abbreviated version of the World Health Organization Quality of Life questionnaire (WHOQOL-BREF) increased more significantly after yoga than after exercise or waiting list control conditions. None of the RCTS encountered adverse events. Dose-response relationships could, however, not be determined.

CONCLUSION

Although the number of RCTs included in this review was limited, results indicated that yoga therapy can be an useful add-on treatment to reduce general psychopathology and positive and negative symptoms. In the same way, HRQL improved in those antipsychotic-stabilised patients with schizophrenia following yoga.