Cognitive impairments in schizophrenia and schizoaffective disorder: relationship with clinical characteristics

Factors associated with cognitive dysfunction in treatment-responsive and -resistant schizophrenia: A pilot cross-sectional study

BACKGROUND

Cognitive dysfunction is a core feature of schizophrenia. Although treatment-resistant schizophrenia (TRS) exhibits wide-ranging neuropsychological deficits, factors defining cognitive prognosis in TRS are unclear. We aimed to clarify the association between cognitive dysfunction and factors, such as plasma concentrations of clozapine (CLZ), N-desmethylclozapine (NDMC), and homovanillic acid (HVA), due to differences in antipsychotic responses in patients with schizophrenia.

METHODS

This pilot cross-sectional study included 60 Japanese patients (35 with TRS and 25 with non-CLZ antipsychotic responders (AR)). Cognitive function was evaluated using the Brief Assessment of Cognition Short Form (BAC-SF). Plasma concentrations of HVA, CLZ, and NDMC were analyzed by high-performance liquid chromatography.

RESULTS

The cognitive performance of patients with AR was better than that of patients with TRS in all tasks. No significant cognitive differences were detected between the CLZ responders and non-responders. The severity of negative and extrapyramidal symptoms was found to be potentially negatively associated with BAC-SF composite and several subtest scores. In patients with TRS, chlorpromazine equivalents and the CLZ/NDMC ratio were identified as factors negatively associated with Digit Sequencing and the Symbol Coding subtest scores of the BAC-SF, respectively.

CONCLUSIONS

Our study suggests that patients with TRS experience worse cognitive dysfunction than those with AR, and CLZ responsiveness in TRS may be not associated with cognitive dysfunction. Additionally, higher chlorpromazine equivalents and the CLZ/NDMC ratio may be associated with severity of cognitive dysfunction in patients with TRS. Further studies are required to clarify the relationship between treatment response and cognitive dysfunction in schizophrenia.

EEG alpha reactivity on eyes opening discriminates patients with schizophrenia and schizoaffective disorder

OBJECTIVE

Alpha activity in the electroencephalogram (EEG) is typically dominant during rest with closed eyes but suppressed by visual stimulation. Previous research has shown that alpha-blockade is less pronounced in schizophrenia patients compared to healthy individuals, but no studies have examined it in schizoaffective disorder.

METHODS

A resting state EEG was used for the analysis of the alpha-reactivity between the eyes closed and the eyes opened conditions in overall (8 - 13 Hz), low (8 - 10 Hz) and high (10 - 13 Hz) alpha bands in three groups: schizophrenia patients (SC, n = 30), schizoaffective disorder (SA, n = 30), and healthy controls (HC, n = 36). All patients had their first psychotic episode and were receiving antipsychotic therapy.

RESULTS

A significant decrease in alpha power was noted across all subjects from the eyes-closed to eyes-open condition, spanning all regions. Alpha reactivity over the posterior regions was lower in SC compared to HC within overall and high alpha. SA showed a trend towards reduced alpha reactivity compared to HC, especially evident over the left posterior region within the overall alpha. Alpha reactivity was more pronounced over the middle and right posterior regions of SA as compared to SC, particularly in the high alpha. Alpha reactivity in SC and SA patients was associated with various negative symptoms.

CONCLUSIONS

Our findings imply distinct alterations in arousal mechanisms in SC and SA and their relation to negative symptomatology. Arousal is more preserved in SA.

SIGNIFICANCE

This study is the first to compare the EEG features of arousal in SC and SA.

Correlations between Negative Symptoms and Cognitive Deficits in Individuals at First Psychotic Episode or at High Risk of Psychosis: A Systematic Review

The present review aims to identify correlations between negative symptoms (NS) and deficits in neurocognition and social cognition in subjects with first-episode psychosis (FEP) and at-high-risk populations (HR). A systematic search of the literature published between 1 January 2005 and 31 December 2022 was conducted on PubMed, Scopus, and PsycInfo. Out of the 4599 records identified, a total of 32 studies met our inclusion/exclusion criteria. Data on a total of 3086 FEP and 1732 HR were collected. The available evidence shows that NS correlate with executive functioning and theory of mind deficits in FEP subjects, and with deficits in the processing speed, attention and vigilance, and working memory in HR subjects. Visual learning and memory do not correlate with NS in either FEP or HR subjects. More inconsistent findings were retrieved in relation to other cognitive domains in both samples. The available evidence is limited by sample and methodological heterogeneity across studies and was rated as poor or average quality for the majority of included studies in both FEP and CHR populations. Further research based on shared definitions of first-episode psychosis and at-risk states, as well as on more recent conceptualizations of negative symptoms and cognitive impairment, is highly needed.

A Digital System (YouXin) to Facilitate Self-Management by People With Psychosis in China: Protocol for a Nonrandomized Validity and Feasibility Study With a Mixed Methods Design

BACKGROUND

Psychosis is one of the most disabling mental health conditions and causes significant personal, social, and economic burden. Accurate and timely symptom monitoring is critical to offering prompt and time-sensitive clinical services. Digital health is a promising solution for the barriers encountered by conventional symptom monitoring approaches, including accessibility, the ecological validity of assessments, and recall bias. However, to date, there has been no digital health technology developed to support self-management for people with psychosis in China.

OBJECTIVE

We report the study protocol to evaluate the validity, feasibility, acceptability, usability, and safety of a symptom self-monitoring smartphone app (YouXin; Chinese name ) for people with psychosis in China.

METHODS

This is a nonrandomized validity and feasibility study with a mixed methods design. The study was approved by the University of Manchester and Beijing Anding Hospital Research Ethics Committee. YouXin is a smartphone app designed to facilitate symptom self-monitoring for people with psychosis. YouXin has 2 core functions: active monitoring of symptoms (ie, smartphone survey) and passive monitoring of behavioral activity (ie, passive data collection via embedded smartphone sensors). The development process of YouXin utilized a systematic coproduction approach. A series of coproduction consultation meetings was conducted by the principal researcher with service users and clinicians to maximize the usability and acceptability of the app for end users. Participants with psychosis aged 16 years to 65 years were recruited from Beijing Anding Hospital, Beijing, China. All participants were invited to use the YouXin app to self-monitor symptoms for 4 weeks. At the end of the 4-week follow-up, we invited participants to take part in a qualitative interview to explore the acceptability of the app and trial procedures postintervention.

RESULTS

Recruitment to the study was initiated in August 2022. Of the 47 participants who were approached for the study from August 2022 to October 2022, 41 participants agreed to take part in the study. We excluded 1 of the 41 participants for not meeting the inclusion criteria, leaving a total of 40 participants who began the study. As of December 2022, 40 participants had completed the study, and the recruitment was complete.

CONCLUSIONS

This study is the first to develop and test a symptom self-monitoring app specifically designed for people with psychosis in China. If the study shows the feasibility of YouXin, a potential future direction is to integrate the app into clinical workflows to facilitate digital mental health care for people with psychosis in China. This study will inform improvements to the app, trial procedures, and implementation strategies with this population. Moreover, the findings of this trial could lead to optimization of digital health technologies designed for people with psychosis in China.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/45170.

Comparable repetition blindness effect in patients with schizophrenia

BACKGROUND AND OBJECTIVES

Repetition blindness (RB) refers to the difficulty to report repetitions of stimuli visually presented in a rapid list. To date only two studies have examined RB in patients with schizophrenia and the results are not clear-cut. The current study was designed to employ a task with reduced memory load, more trials in each experimental condition, and more participants to obtain a more reliable RB effect.

METHODS

A 2x2x3x2 mixed factor repeated measure design was used, with stimulus repetition, lag, and presentation rate as within-subject factors, and group (patient or control) as a between-subject factor. A rapid serial visual presentation (RSVP) procedure was used. Twenty eight inpatients with schizophrenia and 28 healthy controls participated in the experiment.

RESULTS

The patient group showed significantly impaired performance when compared tothe control group in every experimental condition. Nevertheless, the patient group demonstrated similar RB effect as the control group. Furthermore, the overall RB effect observed in patients did not relate to their illness severity or psychotic symptoms. Neither was it related to their age or education.

LIMITATIONS

It was difficult to match the age and education of the control group to that of the inpatient group.

CONCLUSIONS

Patients with schizophrenia performed worse than healthy controls in each experimental condition. Both the control and patient group showed robust RB effect in the short lag with faster rates. In addition, RB effect seemed to be irrelevant to patients' illness severity and clinical symptoms.

Effects of antipsychotic and anticholinergic medications on cognition in chronic patients with schizophrenia

BACKGROUND

Patients with psychosis frequently use a variety of psychotropic medicines, many of which have anticholinergic effects that can impair cognition. Therefore, this study aimed to evaluate whether there is an association between medications used for neuropsychological disorders/symptoms and cognition in patients with schizophrenia, focusing on their anticholinergic load and antipsychotic doses.

STUDY DESIGN

A cross-sectional study between July 2019 and Mars 2020 at the Psychiatric Hospital of the Cross-Lebanon enrolled 120 inpatients diagnosed with schizophrenia. The total anticholinergic burden was calculated based on the Anticholinergic Drug Scale (ADS), and the chlorpromazine equivalent dose was calculated using the Andreasen method to assess the relative antipsychotic dose. Also, the objective cognition was assessed using the Brief Assessment of Cognition in Schizophrenia (BACS) tool.

STUDY RESULTS

A significantly higher BACS total score (r = -0.33, p < 0.001), higher verbal memory (r = -0.26, p = 0.004), higher working memory (r = -0.20, p = 0.03), higher motor speed (r = -0.36, p < 0.001), and higher attention and speed of information processing (r = -0.27, p = 0.003) were significantly associated with lower chlorpromazine equivalent dose. Higher ADS (Standardized Beta (SB) = -.22; p = .028), higher chlorpromazine equivalent dose (SB = -.30; p = .001), and taking mood stabilizer medications (SB = -.24; p = .004) were significantly associated with lower cognition.

CONCLUSION

This study confirms that the cognitive functions of chronic patients with schizophrenia may be affected by medications and their anticholinergic burden. More studies are needed to explain the role of cholinergic neurotransmission and general neurochemical mechanisms in the cognitive impairment of patients with schizophrenia.

Predictive Biomarkers for Antipsychotic Treatment Response in Early Phase of Schizophrenia: Multi-Omic Measures Linking Subcortical Covariant Network, Transcriptomic Signatures, and Peripheral Epigenetics

Background

Volumetric alterations of subcortical structures as predictors of antipsychotic treatment response have been previously corroborated, but less is known about whether their morphological covariance relates to treatment outcome and is driven by gene expression and epigenetic modifications.

Methods

Subcortical volumetric covariance was analyzed by using baseline T1-weighted magnetic resonance imaging (MRI) in 38 healthy controls and 38 drug-naïve first-episode schizophrenia patients. Patients were treated with 8-week risperidone monotherapy and divided into responder and non-responder groups according to the Remission in Schizophrenia Working Group (RSWG). We utilized partial least squares (PLS) regression to examine the spatial associations between gene expression of subcortical structures from a publicly available transcriptomic dataset and between-group variances of structural covariance. The peripheral DNA methylation (DNAm) status of a gene of interest (GOI), overlapping between genes detected in the PLS and 108 schizophrenia candidate gene loci previously reported, was examined in parallel with MRI scanning.

Results

In the psychotic symptom dimension, non-responders had a higher baseline structural covariance in the putamen-hippocampus-pallidum-accumbens pathway compared with responders. For disorganized symptoms, significant differences in baseline structural covariant connections were found in the putamen-hippocampus-pallidum-thalamus circuit between the two subgroups. The imaging variances related to psychotic symptom response were spatially related to the expression of genes enriched in neurobiological processes and dopaminergic pathways. The DNAm of GOI demonstrated significant associations with patients' improvement of psychotic symptoms.

Conclusion

Baseline subcortical structural covariance and peripheral DNAm may relate to antipsychotic treatment response. Phenotypic variations in subcortical connectome related to psychotic symptom response may be transcriptomically and epigenetically underlaid. This study defines a roadmap for future studies investigating multimodal imaging epigenetic biomarkers for treatment response in schizophrenia.

A meta-analysis comparing cognitive function across the mood/psychosis diagnostic spectrum

BACKGROUND

The nature and degree of cognitive impairments in schizoaffective disorder is not well established. The aim of this meta-analysis was to characterise cognitive functioning in schizoaffective disorder and compare it with cognition in schizophrenia and bipolar disorder. Schizoaffective disorder was considered both as a single category and as its two diagnostic subtypes, bipolar and depressive disorder.

METHODS

Following a thorough literature search (468 records identified), we included 31 studies with a total of 1685 participants with schizoaffective disorder, 3357 with schizophrenia and 1095 with bipolar disorder. Meta-analyses were conducted for seven cognitive variables comparing performance between participants with schizoaffective disorder and schizophrenia, and between schizoaffective disorder and bipolar disorder.

RESULTS

Participants with schizoaffective disorder performed worse than those with bipolar disorder (g = -0.30) and better than those with schizophrenia (g = 0.17). Meta-analyses of the subtypes of schizoaffective disorder showed cognitive impairments in participants with the depressive subtype are closer in severity to those seen in participants with schizophrenia (g = 0.08), whereas those with the bipolar subtype were more impaired than those with bipolar disorder (g = -0.23) and less impaired than those with schizophrenia (g = 0.29). Participants with the depressive subtype had worse performance than those with the bipolar subtype but this was not significant (g = 0.25, p = 0.05).

CONCLUSION

Cognitive impairments increase in severity from bipolar disorder to schizoaffective disorder to schizophrenia. Differences between the subtypes of schizoaffective disorder suggest combining the subtypes of schizoaffective disorder may obscure a study's results and hamper efforts to understand the relationship between this disorder and schizophrenia or bipolar disorder.

Preserved intention understanding during moral judgments in schizophrenia

INTRODUCTION

Although there is convincing evidence for socio-cognitive impairments in schizophrenia spectrum disorder (SSD), little evidence is found for deficient moral cognition. We investigated whether patients with SSD showed altered moral judgments in a story task where the protagonist either had a neutral or malicious intention towards another person. This paradigm examined whether SSD relates to altered moral cognition in general or specifically to impaired integration of prior information (such as beliefs) in moral judgments.

METHODS

23 patients and 32 healthy controls read vignettes created in a 2 x 2 design. The protagonist in each story either had a neutral or negative intention towards another person which, as a result, either died (negative outcome) or did not die (neutral outcome). Participants rated the moral permissibility of the protagonist's action. Standard null hypothesis significance testing and equivalent Bayes analyses are reported.

RESULTS

Schizophrenia patients did not differ significantly in permissibility ratings from healthy controls. This finding was supported by the Bayes analyses which favoured the null hypothesis. Task performance was not related to symptom severity or medication.

CONCLUSIONS

The current findings do not support the notion that moral judgments are deficient in schizophrenia. Furthermore, the current study shows that patients do not have observable difficulties in integrating the protagonist's belief in the rating of the moral permissibility of the action-outcome.

A Pilot Study of Cognitive Impairment in Longstanding Electroconvulsive Therapy-treated Schizophrenia Patients Versus Controls

BACKGROUND

Electroconvulsive therapy (ECT), though reliable and effective, is controversial due to its media portrayal as a treatment with severe side effects. Electroconvulsive therapy is mainly given to patients suffering from affective disorders and treatment-resistant schizophrenia. Although past research assessed the amount and duration of memory loss due to ECT, little is known about its influence on cognition for patients suffering from schizophrenia, whose cognitive decline is an inherent part of their illness. We aimed to test whether maintenance ECT causes cognitive decline among elderly schizophrenia patients.

METHODS

Twenty elderly (age >65 years) patients suffering from schizophrenia and schizoaffective disorder who received maintenance ECT were matched with 20 controls suffering from the same illnesses that have never been treated with ECT. The match was based on age, sex, and illness duration. The participants were evaluated using the Montreal Cognitive Assessment for cognitive decline and a Positive and Negative Syndrome Scale (PANSS) for illness severity.

RESULTS

A lower score in the abstraction subscale was found in the maintenance ECT population (P = 0.002), without significant differences in the total Montreal Cognitive Assessment and the delayed-recall subscale scores. In the treatment group, a correlation was found between an impairment in naming and positive symptoms in the PANSS score (r = -0.45) and between abstraction impairment and negative symptoms (r = -0.56) and total PANSS score (r = -0.497).

CONCLUSIONS

Maintenance ECT does not worsen existing global cognitive deficits or delayed recall in elderly schizophrenia patients. The abstraction impairment was possibly due to the higher disease burden of the patients referred to ECT.

Visual N80 latency as a marker of neuropsychological performance in schizophrenia: Evidence for bottom-up cognitive models

OBJECTIVE

Cognitive deficits and visual impairment in the magnocellular (M) pathway, have been independently reported in schizophrenia. The current study examined the association between neuropsychological (NPS) performance and visual evoked potentials (VEPs: N80/P1 to M- and P(parvocellular)-biased visual stimuli) in schizophrenia and healthy controls.

METHODS

NPS performance and VEPs were measured in n = 44 patients and n = 34 matched controls. Standardized NPS-scores were combined into Domains and a PCA (Principal Component Analysis) generated Composite. Group differences were assessed via (M)ANOVAs, association between NPS and VEP parameters via PCA, Pearson's coefficient and bootstrapping. Logistic regression was employed to assess classification power.

RESULTS

Patients showed general cognitive impairment, whereas group differences for VEP-parameters were non-significant. In patients, N80 latency across conditions loaded onto one factor with cognitive composite, showed significant negative correlations of medium effect sizes with NPS performance for M/P mixed stimuli and classified low and high performance with 70% accuracy.

CONCLUSION

The study provides no evidence for early visual pathway impairment but suggests a heightened association between early visual processing and cognitive performance in schizophrenia.

SIGNIFICANCE

Our results lend support to bottom-up models of cognitive function in schizophrenia and implicate visual N80 latency as a potential biomarker of cognitive deficits in schizophrenia.

Dose-dependent effects of antipsychotics on efficacy and adverse effects in schizophrenia

BACKGROUND

Antipsychotics are a cornerstone of pharmacological treatment of schizophrenia. Improved understanding of the dose-response relationship of antipsychotics in terms of efficacy, adverse effects, and mortality can help to optimize the pharmacological treatment of schizophrenia.

METHODS

This narrative literature review summarizes current evidence on the relationship of antipsychotic dose with efficacy, adverse effects, and mortality in patients with schizophrenia.

RESULTS

The efficacy of antipsychotics generally appeared to be highly dose-dependent in the acute phase of schizophrenia, with each antipsychotic having a specific dose-response curve. The presence or absence of dose-dependency and its extent varied according to the type of adverse effect. Parkinsonism, hyperprolactinemia, weight gain, and neurocognitive impairment appeared to be dose-related. The following adverse effects might be at least somewhat dose-dependent: akathisia, tardive dyskinesia, osteoporosis, sexual dysfunction, diabetes mellitus, myocardial infarction, stroke, thromboembolism, QT interval prolongation, anticholinergic adverse effects, somnolence, pneumonia, hip fracture, and neuroleptic malignant syndrome. In contrast, the relationships of antipsychotic dose with dyslipidemia, hypotension, seizure, sialorrhea, and neutropenia and agranulocytosis remained unclear due to mixed findings and/or limited data. Although a higher lifetime cumulative antipsychotic dose might contribute to higher mortality, it is still difficult to conclude whether mortality increases in a dose-dependent manner.

CONCLUSION

These findings could help clinicians to optimize antipsychotic treatment in patients with schizophrenia by balancing risks and benefits in clinical practice. However, further investigations with larger sample sizes and more robust study designs that focus on each antipsychotic agent are needed.

Metacognitive Beliefs, Cognitive Functioning, Psychiatric Symptoms and Empathy in People with Schizophrenia

BACKGROUND

People with schizophrenia often exhibit deficits in empathy, which plays a major role in social cognition and interpersonal relationship. However, little work has investigated potential factors that influence empathy in schizophrenia. The study aimed to investigate the relationship among metacognition, psychiatric symptoms, cognitive functioning and empathy in patients diagnosed with schizophrenia.

METHODS

Forty-eight people with schizophrenia were enrolled in the study group. All subjects participated in the metacognitions questionnaire-30 (MCQ-30), brief psychiatric rating scale (BPRS), neurocognitive functioning, interpersonal reactivity index (IRI), and the pictorial empathy test (PET).

RESULTS

Stepwise regression analysis revealed that cognitive self-consciousness (domain of metacognitions questionnaire-30) accounted for 37% of the variance in perspective taking scores (domain of interpersonal reactivity index). Resistance (subscale of brief psychiatric rating scale) and positive beliefs about worry (domain of metacognitions questionnaire-30) accounted for 34% of the variance in fantasy (domain of interpersonal reactivity index). Activation (subscale of brief psychiatric rating scale) was a significant predictor for empathic concern (domain of interpersonal reactivity index). Resistance, cognitive confidence (domain of metacognitions questionnaire-30), intellectual processes and inhibitory control (go-no-go task) accounted for 38% of the variance in personal distress. Negative symptoms (subscale of brief psychiatric rating scale) and cognitive self-consciousness were significant predictors for the pictorial empathy test.

CONCLUSION

The study was aimed to examine self-perception of metacognitive beliefs and empathy. More research is needed to explore the association between metacognitive beliefs, cognitive functioning and psychiatric symptoms on empathy in people with schizophrenia.

A cognitive model of diminished expression in schizophrenia: The interface of metacognition, cognitive symptoms and language disturbances

The resistance of negative symptoms to pharmacologic treatment has spurred interest in understanding the psychological factors that contribute to their formation and persistence. However, little is understood about the psychological processes that reinforce and sustain the negative symptoms domain of diminished expression. Prior research has shown that higher levels of diminished expression relate to deficits in metacognitive capacity. We propose a more complex model in which diminished expression occurs when impairments in metacognitive self-reflectivity, alterations in higher-order language structure, and cognitive symptoms interact and thus interfere with persons' ability to understand and express emotions in ways others can recognize. Individuals with schizophrenia-spectrum disorders (N = 201) provided personal narratives detailing their life story and reflections about their mental illness. Self-reflectivity was measured with the Metacognition Assessment Scale-Abbreviated, and situation models were extracted from participants' personal narratives via Coh-Metrix 3.0, an automated program that calculates language indices. Diminished expression and cognitive symptoms were measured with the Positive and Negative Syndrome Scale. Structural equation models (SEM) examined whether self-reflectivity mediated the impact of cognitive symptoms and situation models on diminished expression. Results of the SEM revealed that self-reflectivity partially mediated the impact of situation models on diminished expression (β = -.073, p = .008, ±95% CI [-0.126, -0.019]). and fully mediated the influence of cognitive symptoms in diminished expression (β = 0.099, p = .001, ±95% CI [0.038, 0.160]). In conclusion, results suggest that self-reflectivity, linguistic cohesion, and cognitive symptoms may be useful targets for intervention in efforts to treat diminished expression in psychosis.

Improving social functioning in community-dwelling patients with schizophrenia: a randomized controlled computer cognitive remediation therapy trial with six months follow-up

Computerized cognitive remediation therapy (CCRT) has been found to generally improve cognition among patients with schizophrenia, but its effect on functioning has not been extensively studied. This study addressed this gap in the literature by investigating the effect of CCRT and its long-term efficacy among community-dwelling patients with schizophrenia. 157 Chinese patients with schizophrenia were recruited from communities and randomized to CCRT (n = 78) or treatment as usual (TAU; n = 79) groups for 12 weeks with 4-5 sessions per week. Neurocognition, functioning, and symptoms of participants were assessed at baseline, after treatment, and at the 6 month follow-up. The CCRT group showed significantly greater improvements than the TAU group regarding the MATRICS Consensus Cognitive Battery (MCCB) total score and social cognition score. Significant cognitive benefits for functioning were observed (Personal and Social Performance scale, PSP). Moreover, improvement of the MCCB total score mediated a positive effect on functional capacity (UCSD Performance-based Skills Assessment, UPSA), and mediated decreases in negative symptoms across both groups. CCRT improved social functioning and general cognitive functioning among community-dwelling patients with schizophrenia. These improvements persisted for 6 months after treatment. CCRT also led to improvements in functioning and symptom severity by modulating cognitive functioning.

Disparate effects of first and second generation antipsychotics on cognition in schizophrenia - Findings from the randomized NeSSy trial

Cognitive impairment represents a core feature of schizophrenia. Uncertainty about demonstrable benefits of available antipsychotics on cognition remains an important clinical question relevant to patients' quality of life. The aim of our multi-center, randomized, double-blind "Neuroleptic Strategy Study" (NeSSy) was to compare the effectiveness of selected antipsychotics, conventionally classified as second- (SGAs) (haloperidol, flupentixol) and first generation antipsychotics (FGAs) (aripiprazole, olanzapine, quetiapine), on quality of life in schizophrenia. The effects on cognitive deficits represented a secondary outcome. We used an innovative double randomization for assignment of treatment group, and followed the patients with a neurocognitive test-battery upon six and 24 weeks of treatment. Psychopathology and quality of life were assessed using CGI, PANSS and SF-36. Assessment of cognitive performance was conducted in 114 of the 136 randomized patients. The SGA group (N = 62) showed beneficial effects of small to moderate effect size on cognition during the initial six weeks of treatment (executive functions, verbal fluency) and at 24 weeks (executive functions, working memory). In contrast, the FGA group (N = 52) showed moderately improved executive function, but a decline in verbal fluency at six weeks, with significant declines of moderate to large effect size in executive function, verbal learning and memory, and verbal fluency at 24 weeks. Our study indicates that SGAs present an advantage over FGAs regarding cognitive function during a medium-term treatment for schizophrenia. The results further emphasize a distinction between progression to detrimental effects of FGAs with prolonged treatment in contrast to more persistent cognitive benefits with SGA treatment.

Differential diagnosis of schizophrenia and schizoaffective disorder from normal subjects using virtual reality

Dysfunction of allocentric and egocentric memories is one of the core features of psychiatric disorders. There are a few navigational studies on these memories in schizophrenia and bipolar disorders, but studies in schizoaffective disorder are lacking. Here, we aim to explore allocentric and egocentric navigation deficits in these subjects using our advanced recently developed virtual reality navigation task (VRNT). Twenty patients with schizophrenia and 20 with schizoaffective disorder were compared with 20 normal volunteer subjects on VRNTs consisting of a virtual neighbourhood (allocentric memory) and a virtual maze (egocentric memory). Compared with schizoaffective disorder and control subjects, patients with schizophrenia had the worst performance on both virtual neighbourhood and virtual maze tasks. The allocentric memory in both patients with schizophrenia and those with schizoaffective disorder was more impaired than the egocentric memory (p ˂ 0.001). However, the patients with schizoaffective disorder performed better in egocentric memory than those with schizophrenia, as they had fewer errors in the virtual maze. It was concluded that allocentric memory is more impaired than egocentric in both schizoaffective disorder and schizophrenia patients, whereas patients with schizoaffective disorder performed better in egocentric memory than patients with schizophrenia. It was also concluded that allocentric memory deficits can help differentiate patients with schizophrenia and schizoaffective disorder from healthy participants, whereas egocentric memory deficits can be used to distinguish them from each other.

The continuing story of schizophrenia and schizoaffective disorder: One condition or two?

Although schizophrenia and schizoaffective disorder remain separable in diagnostic systems, the validity of the distinction is uncertain. This study asked whether schizophrenia and schizoaffective disorder are distinguishable on selected cognitive, social cognitive and structural social brain measures. Outpatients with a diagnosis of schizophrenia (n = 44) or schizoaffective disorder (n = 29) and non-psychiatric control participants (n = 62) were studied. Patients were assessed clinically (Positive and Negative Syndrome Scale) and all participants were administered a battery of cognitive (MATRICS Consensus Cognitive Battery; Wechsler Abbreviated Scale of Intelligence, Wide Range Achievement Reading) and social cognitive (Reading the Mind in the Eyes, Mayer-Salovey-Caruso Emotional Intelligence Test; MSCEIT) tasks. In addition, participants underwent structural magnetic resonance imaging (MRI) to yield cortical thickness data for 42 regions associated with the social brain network. Results showed no significant differences between patient groups on 17/18 cognitive/social cognitive and social brain cortical thickness measures. In contrast, schizophrenia and schizoaffective disorder patients differed from controls on 16/18 and 11/18 measures respectively. Schizoaffective disorder patients outperformed schizophrenia patients on an emotion regulation task (MSCEIT). Schizophrenia and schizoaffective disorder are largely indistinguishable on key cognitive, social cognitive and neural measures. The continuing separation of these syndromes in diagnostic systems and disease models requires is questionable and requires further attention.

Self-perception of mental illness, and subjective and objective cognitive functioning in people with schizophrenia

Background: People with schizophrenia may have a negative self-perception of mental illness. However, the relationship between the self-perception of illness and subjective and objective cognitive functioning remains unclear. Method: Thirty-seven people with schizophrenia were enrolled in the study group. All subjects completed self-reported self-perception of mental illness questionnaires (Birchwood Insight Scale [BIS], Internalized Stigma of Mental Illness [ISMI]), subjective cognitive functioning (Scale to Investigate Cognition in Schizophrenia [SSTICS]) and objective cognitive functioning (Luria Nebraska Neuropsychological Battery [LNNB]). Results: Spearman's rank analysis showed that awareness of illness (domain of insight) was positively associated with most domains of SSTICS and ISMI. Total insight was positively correlated with alienation (domain of ISMI).  Need for treatment (domain of insight) was negatively correlated with stigma resistance (domain of ISMI). Awareness of symptoms (domain of insight) and total insight were negatively associated with receptive speech and arithmetic (LNNB subtest), respectively. ISMI was positively correlated with most domains of SSTICS, but not with LNNB. The group with good insight had higher scores in attention (domain of SSTICS) and total SSTICS and alienation, stereotype endorsement, social withdrawal (domains of ISMI) and total ISMI than the group with poor insight. The group with mild to moderate internalized stigma had higher scores in explicit memory, attention, language, praxia (domains of SSTICS) and total SSTICS than the group with no internalized stigma. Conclusion: We identified that awareness of illness (domain of insight), internalized stigma were significantly associated with most domains of SSTICS, but not with LNNB. Total insight and awareness of symptoms (domain of insight) were significantly associated with receptive speech and arithmetic (LNNB subtest), respectively. Schizophrenia with higher insight or more internalized stigma reported more subjective cognitive impairment. Future studies with larger samples involving follow up are necessary to verify our findings and extend the applicability.

Antidopaminergic medication in healthy subjects provokes subjective and objective mental impairments tightly correlated with perturbation of biogenic monoamine metabolism and prolactin secretion

OBJECTIVES

Off-label prescription of antipsychotics to patients without psychotic symptoms has become a routine matter for many psychiatrists and also some general practitioners. Nonetheless, little is known about the possibly detrimental effects of antidopaminergic medications on general psychopathology, subjective mental state, or a possible association with physiological parameters in nonpsychotic individuals.

METHODS

In this randomized, single-blinded study, groups of healthy volunteers (n=18) received low doses of reserpine, aripiprazole, haloperidol, or placebo on 7 successive days. Relevant physiological parameters (plasma prolactin, concentrations of catecholamine metabolites in plasma, and 24-hour urine) and each subject's mental state (Positive and Negative Syndrome Scale, Hamilton Rating Scale for Depression, visual analogue scale, Beck Depression Inventory II) were assessed at the start and end of the trial.

RESULTS

Of the three active treatments, only reserpine caused a significant increase in some plasma- and urine-catecholamine metabolites, but all three medications evoked objective and subjective changes in general psychopathology scores, which correlated with individual increases in plasma homovanillic acid concentrations. Both objective and subjective impairments were significantly more pronounced in the subgroup with greatest increase of plasma prolactin. Subjects experiencing the most pronounced side effects under haloperidol, which compelled them to drop out, showed significantly higher prolactin concentration increases than those who tolerated haloperidol well.

CONCLUSION

We found consistent associations between altered markers of dopamine transmission and several objective and subjective mental impairments in healthy volunteers after 1 week's treatment with antidopaminergic medications. These findings should draw attention to a more intensive risk-benefit evaluation in cases of off-label prescription of antipsychotic medications.

Characteristics and Service Use of Older Adults with Schizoaffective Disorder Versus Older Adults with Schizophrenia and Bipolar Disorder

OBJECTIVE

The purpose of this study was to determine if schizoaffective disorder in older adults is differentiated from schizophrenia and bipolar disorder with respect to community functioning, cognitive functioning, psychiatric symptoms, and service use.

DESIGN

Secondary analysis of baseline data collected from the Helping Older People Experience Success psychosocial skills training and health management study.

SETTING

Three community mental health centers in New Hampshire and Massachusetts.

PARTICIPANTS

Adults over the age of 50 (N = 139, mean age: 59.7 years, SD: 7.4 years) with persistent functional impairment and a diagnosis of schizoaffective disorder (N = 52), schizophrenia (N = 51), or bipolar disorder (N = 36).

MEASUREMENTS

Health status (36-Item Short Form Health Survey [SF-36]), performance-based community living skills (UCSD Performance-Based Skills Assessment), neuropsychological functioning (Delis-Kaplan Executive Functioning subtests), psychiatric symptoms (Brief Psychiatric Rating Scale, Center for Epidemiologic Studies Depression Scale, Scale for the Assessment of Negative Symptoms), medical severity (Charlson comorbidity index), and acute service use.

RESULTS

Older adults with schizoaffective disorder had depressive symptoms of similar severity to bipolar disorder, and thought disorder symptoms of similar severity to schizophrenia. Schizoaffective disorder compared with schizophrenia was associated with better community functioning, but poorer subjective physical and mental health functioning as measured by the SF-36. Older adults with schizoaffective disorder had greater acute hospitalization compared with adults with schizophrenia, though their use of acute care services was comparable to individuals with bipolar disorder.

CONCLUSIONS

Findings from this study suggest that schizoaffective disorder in older adults occupies a distinct profile from either schizophrenia or bipolar disorder with respect to community functional status, symptom profile, and acute services utilization.

Lifetime use of psychiatric medications and cognition at 43years of age in schizophrenia in the Northern Finland Birth Cohort 1966

BACKGROUND

Higher lifetime antipsychotic exposure has been associated with poorer cognition in schizophrenia. The cognitive effects of adjunctive psychiatric medications and lifetime trends of antipsychotic use remain largely unclear. We aimed to study how lifetime and current benzodiazepine and antidepressant medications, lifetime trends of antipsychotic use and antipsychotic polypharmacy are associated with cognitive performance in midlife schizophrenia.

METHODS

Sixty participants with DSM-IV schizophrenia from the Northern Finland Birth Cohort 1966 were examined at 43years of age with an extensive cognitive test battery. Cumulative lifetime and current use of psychiatric medications were collected from medical records and interviews. The associations between medication and principal component analysis-based cognitive composite score were analysed using linear regression.

RESULTS

Lifetime cumulative DDD years of benzodiazepine and antidepressant medications were not significantly associated with global cognition. Being without antipsychotic medication (for minimum 11months) before the cognitive examination was associated with better cognitive performance (P=0.007) and higher lifetime cumulative DDD years of antipsychotics with poorer cognition (P=0.020), when adjusted for gender, onset age and lifetime hospital treatment days. Other lifetime trends of antipsychotic use, such as a long antipsychotic-free period earlier in the treatment history, and antipsychotic polypharmacy, were not significantly associated with cognition.

CONCLUSIONS

Based on these naturalistic data, low exposure to adjunctive benzodiazepine and antidepressant medications does not seem to affect cognition nor explain the possible negative effects of high dose long-term antipsychotic medication on cognition in schizophrenia.

Lifetime antipsychotic medication and cognitive performance in schizophrenia at age 43 years in a general population birth cohort

This naturalistic study analysed the association between cumulative lifetime antipsychotic dose and cognition in schizophrenia after an average of 16.5 years of illness. Sixty participants with schizophrenia and 191 controls from the Northern Finland Birth Cohort 1966 were assessed at age 43 years with a neurocognitive test battery. Cumulative lifetime antipsychotic dose-years were collected from medical records and interviews. The association between antipsychotic dose-years and a cognitive composite score based on principal component analysis was analysed using linear regression. Higher lifetime antipsychotic dose-years were significantly associated with poorer cognitive composite score, when adjusted for gender, onset age and lifetime hospital treatment days. The effects of typical and atypical antipsychotics did not differ. This is the first report of an association between cumulative lifetime antipsychotic dose and global cognition in midlife schizophrenia. Based on these data, higher lifetime antipsychotic dose-years may be associated with poorer cognitive performance at age 43 years. Potential biases related to the naturalistic design may partly explain the results; nonetheless, it is possible that large antipsychotic doses harm cognition in schizophrenia in the long-term.

Self concepts, health locus of control and cognitive functioning associated with health-promoting lifestyles in schizophrenia

PURPOSE

The study aimed to investigate the relationship among self concepts, health locus of control, cognitive functioning and health-promoting lifestyles in patients diagnosed with schizophrenia. We examined health-promoting lifestyles through self-efficacy, self-esteem, health locus of control and neurocognitive factors.

METHOD

Fifty-six people with schizophrenia were enrolled in the study group. All subjects participated in the self-esteem (Rosenberg Self-Esteem Scale), self-efficacy (General Self-Efficacy Scale), health locus of control (The Multidimensional Health Locus of Control Scales), health-promoting lifestyles (Health Promotion Life-style Profile-II) and a series of neurocognitive measures.

FINDINGS

Stepwise regression analysis revealed that self-efficacy, internal health locus of control and attentional set-shifting accounted for 42% of the variance in total health-promoting lifestyles scores. Self-efficacy, self-esteem, internal and powerful others health locus of control and attentional set-shifting were significant predictors for domains of health-promoting lifestyles, respectively.

CONCLUSION

Study findings can help mental health professionals maintain and improve health-promoting behaviors through a better understanding of self-esteem, self-efficacy, health locus of control and neurocognitive functioning among people with schizophrenia.

The effects of arousal on apical amplification and conscious state

Neocortical pyramidal cells can integrate two classes of input separately and use one to modulate response to the other. Their tuft dendrites are electrotonically separated from basal dendrites and soma by the apical dendrite, and apical hyperpolarization-activated currents (Ih) further isolate subthreshold integration of tuft inputs. When apical depolarization exceeds a threshold, however, it can enhance response to the basal inputs that specify the cell's selective sensitivity. This process is referred to as apical amplification (AA). We review evidence suggesting that, by regulating Ih in the apical compartments, adrenergic arousal controls the coupling between apical and somatic integration zones thus modifying cognitive capabilities closely associated with consciousness. Evidence relating AA to schizophrenia, sleep, and anesthesia is reviewed, and we assess theories that emphasize the relevance of AA to consciousness. Implications for theories of neocortical computation that emphasize context-sensitive modulation are summarized. We conclude that the findings concerning AA and its regulation by arousal offer a new perspective on states of consciousness, the function and evolution of neocortex, and psychopathology. Many issues worthy of closer examination arise.

Neuropsychological and neuroimaging underpinnings of schizoaffective disorder: a systematic review

OBJECTIVES

The neurobiological basis and nosological status of schizoaffective disorder remains elusive and controversial. This study provides a systematic review of neurocognitive and neuroimaging findings in the disorder.

METHODS

A comprehensive literature search was conducted via PubMed, ScienceDirect, Scopus and Web of Knowledge (from 1949 to 31st March 2015) using the keyword 'schizoaffective disorder' and any of the following terms: 'neuropsychology', 'cognition', 'structural neuroimaging', 'functional neuroimaging', 'multimodal', 'DTI' and 'VBM'. Only studies that explicitly examined a well defined sample, or subsample, of patients with schizoaffective disorder were included.

RESULTS

Twenty-two of 43 neuropsychological and 19 of 51 neuroimaging articles fulfilled inclusion criteria. We found a general trend towards schizophrenia and schizoaffective disorder being related to worse cognitive performance than bipolar disorder. Grey matter volume loss in schizoaffective disorder is also more comparable to schizophrenia than to bipolar disorder which seems consistent across further neuroimaging techniques.

CONCLUSIONS

Neurocognitive and neuroimaging abnormalities in schizoaffective disorder resemble more schizophrenia than bipolar disorder. This is suggestive for schizoaffective disorder being a subtype of schizophrenia or being part of the continuum spectrum model of psychosis, with schizoaffective disorder being more skewed towards schizophrenia than bipolar disorder.

Cognitive remediation for older community-dwelling individuals with schizophrenia: a pilot and feasibility study

OBJECTIVE

Cognitive deficits are among the strongest predictors of function in individuals with schizophrenia. This relationship continues to be strong as these individuals grow older into their eight decade. Cognitive remediation (CR) improves cognition in individuals with schizophrenia. This study aims at assessing the feasibility and potential effect of CR in patients with schizophrenia 60 years of age or older.

METHODS

We adapted a CR protocol involving restorative and strategy-based methods over four cohorts of older outpatients with schizophrenia to target cognitive deficits associated with aging and schizophrenia. CR was provided in eight, 2-h weekly didactic sessions and online at-home exercises. Computerized drill and practice exercises were used with bridging to activities of daily life. Computer exercise selection and difficulty level parameters optimized adherence. Progression individually determined difficulty levels. We modified computer laboratory ergonomics to accommodate mobility needs. Participants were assessed at baseline and end-of-study using clinical and cognitive assessments.

RESULTS

Twenty-two participants enrolled: 18 (mean [SD] age: 69.8 [5.3]) completed CR. Mean (SD) global cognition T score from the Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery was 27.7 (10) at baseline and 28.8 (9.7) at the completion of the study. These means are over 2 SD below the norms. The change in global cognition was not statistically significant (paired t(17) = -1.18, p = 0.25).

CONCLUSIONS

Our pilot study suggests that CR is well tolerated by most older outpatients with schizophrenia. Future studies need to assess whether increasing the frequency or the number of CR sessions leads to significant improvement in cognition.

Application of the Audio Recorded Cognitive Screen and its relation to functioning in schizophrenia

OBJECTIVE

This study investigated the ability of the Audio Recorded Cognitive Screen (ARCS) to detect cognitive deficit in individuals with schizophrenia, relative to the Mini Mental State Examination (MMSE) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), and explored the associations between the ARCS and functional outcomes. We hypothesised that the ARCS would be able to better discriminate between individuals with schizophrenia and healthy controls than the MMSE, and that ARCS performance would be correlated with measures of social and vocational functioning.

METHODS

The participants were 19 community-dwelling individuals with schizophrenia or schizoaffective disorder and 19 healthy controls recruited from the Australian Schizophrenia Research Bank (ASRB). Participants completed the ARCS, MMSE, and self-report measures of social and vocational functioning. Clinical and diagnostic data stored by the ASRB were also utilised.

RESULTS

The schizophrenia group performed worse than the control group on the ARCS, with memory, t(36)=2.49, p=0.02, 95% CI [-1.84, -18.79] and fluency, t(36)=2.40, p=0.02, 95% CI [-1.87, -22.24] domains being the main discriminating measures. The RBANS also discriminated between the two groups, and ARCS and RBANS total scores were moderately to strongly correlated. There was no difference between the two groups on the MMSE after controlling for demographic variables. ARCS performance was associated with employment status [χ2(1)=7.16, p=0.007].

CONCLUSION

The ARCS may be sensitive to the cognitive deficits in outpatients with schizophrenia and an indicator of functional outcomes in this population.

Lifetime use of antipsychotic medication and its relation to change of verbal learning and memory in midlife schizophrenia - An observational 9-year follow-up study

BACKGROUND

The association between the course of cognition and long-term antipsychotic medication in schizophrenia remains unclear. We analysed the association between cumulative lifetime antipsychotic medication dose and change of verbal learning and memory during a 9-year follow-up.

METHOD

Forty schizophrenia subjects and 73 controls from the Northern Finland Birth Cohort 1966 were assessed by California Verbal Learning Test (CVLT) at the ages of 34 and 43 years. Data on the lifetime antipsychotic doses in chlorpromazine equivalents were collected. The association between antipsychotic dose-years and baseline performance and change in CVLT was analysed, controlling for baseline performance, gender, age of onset and severity of illness.

RESULTS

Higher antipsychotic dose-years by baseline were significantly associated with poorer baseline performance in several dimensions of verbal learning and memory, and with a larger decrease in short-delay free recall during the follow-up (p=0.031). Higher antipsychotic dose-years during the follow-up were associated with a larger decrease of immediate free recall of trials 1-5 during the follow-up (p=0.039). Compared to controls, decline was greater in some CVLT variables among those using high-doses, but not among those using low-doses.

CONCLUSION

This is the first report of an association between cumulative lifetime antipsychotic use and change in cognition in a long-term naturalistic follow-up. The use of high doses of antipsychotics may be associated with a decrease in verbal learning and memory in schizophrenia years after illness onset. The results do not support the view that antipsychotics in general prevent cognitive decline or promote cognitive recovery in schizophrenia.

Differential cognitive performances between schizophrenic responders and non-responders to antipsychotics: correlation with course of the illness, psychopathology, attitude to the treatment and antipsychotics doses

Multiple lines of evidence demonstrate that schizophrenia patients may perform worse than normal controls in several cognitive tasks. However, little is known on putative differences in cognitive functioning between schizophrenia patients responding to antipsychotics and those resistant to the treatment. In this cross-sectional study, 63 subjects (41 schizophrenia and schizoaffective patients and 22 age and sex-matched controls) were enrolled. Patients were divided in resistant (TRS, n=19) and non-resistant to pharmacological treatment (non-TRS, n=22) according to the American Psychiatric Association (APA) criteria for treatment resistance. The Brief Assessment of Cognition in Schizophrenia (BACS) was administered to patients and controls. The following rating scales were administered to schizophrenia patients: the Positive and Negative Syndrome Scale (PANSS), the Drug Attitude Inventory (DAI) and the Subjective Well-being under Neuroleptics (SWN). Statistically significant differences among non-TRS patients, TRS ones, and controls were detected at the BACS. TRS patients performed significantly worse than non-TRS ones on Verbal Memory task, exhibited higher PANSS total and subscales scores and were prescribed higher antipsychotic doses. Poorer performances at the BACS significantly correlated with more severe negative symptoms in TRS but not in non-TRS patients. These results may suggest that TRS patients suffer from a form of the disease with prominent cognitive impairment possibly related to negative symptoms.

Lifetime cannabis use and cognition in patients with schizophrenia spectrum disorders and their unaffected siblings

The relationship between cannabis and cognitive performance is controversial. While both acute administration and long-term cannabis use impair cognitive performance in healthy subjects, several studies have shown improved cognitive outcomes in patients with schizophrenia spectrum disorders who use cannabis. The aim of this study was to determine the relationship between lifetime cannabis use, as assessed longitudinally over 10 years of follow-up in a sample of 42 patients and 35 of their unaffected siblings, and current cognitive performance. Forty-two healthy control subjects were assessed at follow-up with the same instruments. Stepwise linear regression revealed a negative effect of longitudinal cannabis use on performance in a social cognition task in the patient group. In the sibling group, lifetime cannabis use had a negative effect on processing speed and declarative memory performance. In the control group, cannabis use per se did not predict cognitive performance; however, when adding lifetime tobacco use to the model, we found a negative association between lifetime cannabis and tobacco use and processing speed and social cognition performance. Moreover, a lower IQ associated with current cannabis use predicted worse attentional performance in the control group. The differential pattern of associations between cannabis use and cognitive performance in patients compared with siblings and controls can be explained by the negative impact of illness on cognition.

The global cognitive impairment in schizophrenia: consistent over decades and around the world

OBJECTIVE

Schizophrenia results in cognitive impairments as well as positive, negative, and disorganized symptomatology. The present study examines the extent to which these cognitive deficits are generalized across domains, potential moderator variables, and whether the pattern of cognitive findings reported in schizophrenia has remained consistent over time and across cultural and geographic variation.

METHOD

Relevant publications from 2006 to 2011 were identified through keyword searches in PubMed and an examination of reference lists. Studies were included if they (1) compared the cognitive performance of adult schizophrenia patients and healthy controls, (2) based schizophrenia diagnoses on contemporary diagnostic criteria, (3) reported information sufficient to permit effect size calculation, (4) were reported in English, and (5) reported data for neuropsychological tests falling into at least 3 distinct cognitive domains. A set of 100 non-overlapping studies was identified, and effect sizes (Hedge's g) were calculated for each cognitive variable.

RESULTS

Consistent with earlier analyses, patients with schizophrenia scored significantly lower than controls across all cognitive tests and domains (grand mean effect size, g=-1.03). Patients showed somewhat larger impairments in the domains of processing speed (g=-1.25) and episodic memory (g=-1.23). Our results also showed few inconsistencies when grouped by geographic region.

CONCLUSIONS

The present study extends findings from 1980 to 2006 of a substantial, generalized cognitive impairment in schizophrenia, demonstrating that this finding has remained robust over time despite changes in assessment instruments and alterations in diagnostic criteria, and that it manifests similarly in different regions of the world despite linguistic and cultural differences.

Cognitive functioning correlates of self-esteem and health locus of control in schizophrenia

AIM

The study aimed to investigate the relationship among sociodemographic factors, neurocognitive factors, self-esteem, and health locus of control in patients diagnosed with schizophrenia. We examined the self-esteem, internal health locus of control, and external health locus of control through sociodemographic and neurocognitive factors.

METHODS

Forty-six schizophrenic patients and 31 healthy residents from the community or hospital were recruited as the control group. All subjects participated in the self-esteem questionnaire, health locus of control questionnaire, and a series of neuropychological measures.

RESULTS

Multiple regression analysis revealed that inhibition of attention and external health locus of control were predictors for self-esteem (r=-0.30, P<0.05; r=0.41, P<0.01); inhibition of attention and external health locus of control were contributors for internal health locus of control (r=-0.43, P<0.01; r=0.61, P<0.001); and education was related to external health locus of control (r=-0.31, P<0.05).

CONCLUSION

The current study integrated background characteristics and cognitive function to better understand the impact of self-esteem and health locus of control in schizophrenia. The findings indicated that inhibition of attention, external health locus of control, and education contributed to self-esteem, internal health locus of control and external health locus of control. However, the overall predicted variance accounted for by these predictors was small; thus, further research is necessary to examine imperative variables related with self-esteem and health locus of control in schizophrenia.

The dynamics of DNA methylation in schizophrenia and related psychiatric disorders

Major psychiatric disorders such as schizophrenia (SZ) and bipolar disorder (BP) with psychosis (BP+) express a complex symptomatology characterized by positive symptoms, negative symptoms, and cognitive impairment. Postmortem studies of human SZ and BP+ brains show considerable alterations in the transcriptome of a variety of cortical structures, including multiple mRNAs that are downregulated in both inhibitory GABAergic and excitatory pyramidal neurons compared with non-psychiatric subjects (NPS). Several reports show increased expression of DNA methyltransferases in telencephalic GABAergic neurons. Accumulating evidence suggests a critical role for altered DNA methylation processes in the pathogenesis of SZ and related psychiatric disorders. The establishment and maintenance of CpG site methylation is essential during central nervous system differentiation and this methylation has been implicated in synaptic plasticity, learning, and memory. Atypical hypermethylation of candidate gene promoters expressed in GABAergic neurons is associated with transcriptional downregulation of the corresponding mRNAs, including glutamic acid decarboxylase 67 (GAD67) and reelin (RELN). Recent reports indicate that the methylation status of promoter proximal CpG dinucleotides is in a dynamic balance between DNA methylation and DNA hydroxymethylation. Hydroxymethylation and subsequent DNA demethylation is more complex and involves additional proteins downstream of 5-hydroxymethylcytosine, including members of the base excision repair (BER) pathway. Recent advances in our understanding of altered CpG methylation, hydroxymethylation, and active DNA demethylation provide a framework for the identification of new targets, which may be exploited for the pharmacological intervention of the psychosis associated with SZ and possibly BP+.