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Background: Neurocognitive impairment is a core feature of schizophrenia spectrum disorders (SSDs), and the relationship between cognition and symptoms in SSDs has been widely researched. Negative symptoms are related to a wide range of cognitive impairments; however, the aspects of negative symptoms that underpin this relationship have yet to be specified., Study Design: We used iterative Constrained Principal Component Analysis (iCPCA) to explore the relationship between 18 cognitive measures (including processing speed, attention, working, spatial and verbal memory and executive functions) and 46 symptoms in schizophrenia at the individual item level while minimizing the risk of Type I errors. ICPCA was conducted on a sample of SSD patients in the early stages of psychiatric treatment (n = 121) to determine the components of cognition overlapping with symptoms measured by the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS)., Results: We found that a verbal memory component was associated with items from SANS and SAPS related to impoverished and disorganized emotional communication, language, and thought. In contrast, a working memory component was associated with SANS items related to motor system impoverishment., Conclusions: The iCPCA allowed us to explore the associations between individual items, optimized to understand the overlap between symptoms and cognition. The specific symptoms linked to verbal and working memory impairments imply distinct brain networks, which further investigation may lead to our deeper understanding of the illness and the development of treatment methods., Competing Interests: Declaration of competing interest There are no financial or other conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Machine learning can be used to define subtypes of psychiatric conditions based on shared biological foundations of mental disorders. Here we analyzed cross-sectional brain images from 4,222 individuals with schizophrenia and 7038 healthy subjects pooled across 41 international cohorts from the ENIGMA, non-ENIGMA cohorts and public datasets. Using the Subtype and Stage Inference (SuStaIn) algorithm, we identify two distinct neurostructural subgroups by mapping the spatial and temporal 'trajectory' of gray matter change in schizophrenia. Subgroup 1 was characterized by an early cortical-predominant loss with enlarged striatum, whereas subgroup 2 displayed an early subcortical-predominant loss in the hippocampus, striatum and other subcortical regions. We confirmed the reproducibility of the two neurostructural subtypes across various sample sites, including Europe, North America and East Asia. This imaging-based taxonomy holds the potential to identify individuals with shared neurobiological attributes, thereby suggesting the viability of redefining existing disorder constructs based on biological factors., (© 2024. The Author(s).)

Objectives: Neurocognitive deficits in schizophrenia have a major impact on functioning; however, they remain poorly targeted by available treatment offerings. Cognitive remediation (CR) is effective in improving neurocognition and functioning. Despite clinical guidelines for schizophrenia recommending CR, it is still not readily available in clinical services and sizeable attrition rates are reported in clinical trials., Method: To elucidate the barriers and facilitators of CR access and engagement, we conducted a mixed methods qualitative-dominant study with 12 clinicians in Australia, in 2021, with 1 hr interviews and additional rating scales completed., Results: Thematic analysis highlighted four themes (cognitive symptoms, CR intervention, motivation and engagement in CR, and CR implementation), and 14 subthemes. Clinicians emphasized the broad impact of cognitive deficits and outlined pros and cons of different CR approaches. Several factors were suggested as impacting engagement, including motivation assessments/techniques, neurocognitive insight, illness, and demographic factors. Lack of routine implementation in Australia was unanimously espoused and partly explained by a need for cost-effectiveness analyses, remote and flexible delivery, and increasing service resource provision and staff training in CR., Conclusions: This study offers key insights into CR access, while recommending methods for optimizing CR implementation and dissemination to improve recovery outcomes of people diagnosed with schizophrenia. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Introduction: Hallucinations can be experienced across multiple sensory modalities, but psychiatric studies investigating the cognitive mechanisms of hallucinations have been somewhat restricted to the auditory domain. This study explored the cognitive profiles of individuals experiencing multisensory hallucinations (MH) in schizophrenia-spectrum disorders (SSD) and compared these to those experiencing unimodal auditory hallucinations (AH) or no hallucinations (NH)., Methods: Participants included SSD patients ( n  = 119) stratified by current hallucination status (NH, AH, MH) and nonclinical controls (NCs; n  = 113). Group performance was compared across several cognitive domains: speed of processing, attention, working memory, verbal learning, visual learning, reasoning and problem-solving, social cognition, and inhibition., Results: The clinical groups performed worse than NCs but differences between the clinical groups were not evident across most cognitive domains. Exploratory analyses revealed that the MH group was more impaired on the visual learning task compared to the NH (but not AH) group., Conclusions: Preliminary results suggest that impaired visual learning may be related to MH. This could be attributed to the presence of visual hallucinations (VH), or greater psychopathology, in this group. However, replication is needed, as well as the investigation of other potential cognitive mechanisms of MH.

Background: Auditory verbal hallucinations (AVH), or voice-hearing, can be a prominent symptom during fluctuating mood states in bipolar disorder (BD)., Aims: The current study aimed to: (i) compare AVH-related distress in BD relative to schizophrenia (SCZ), (ii) examine correlations between phenomenology and voice beliefs across each group, and (iii) explore how voice beliefs may uniquely contribute to distress in BD and SCZ., Method: Participants were recruited from two international sites in Australia (BD=31; SCZ=50) and the UK (BD=17). Basic demographic-clinical information was collected, and mood symptoms were assessed. To document AVH characteristics, a 4-factor model of the Psychotic Symptoms Rating Scale and the Beliefs about Voices Questionnaire-Revised were used. Statistical analyses consisted of group-wise comparisons, Pearson's correlations and multiple hierarchical regressions., Results: It was found that AVH-related distress was not significantly higher in BD than SCZ, but those with BD made significantly more internal attributions for their voices. In the BD group, AVH-related distress was significantly positively correlated with malevolence, omnipotence and resistance, However, only resistance, alongside mania and depressive symptoms, significantly contributed to AVH-related distress in BD., Discussion: Our findings have several clinical implications, including identification of voice resistance as a potential therapeutic target to prioritise in BD. Factoring in the influence of mood symptoms on AVH-related distress as well as adopting more acceptance-oriented therapies may also be of benefit.

Background: Schizophrenia and bipolar disorder are complex mental illnesses that are associated with cognitive deficits. There is considerable cognitive heterogeneity that exists within both disorders. Studies that cluster schizophrenia and bipolar patients into subgroups based on their cognitive profile increasingly demonstrate that, relative to healthy controls, there is a severely compromised subgroup and a relatively intact subgroup. There is emerging evidence that telomere shortening, a marker of cellular senescence, may be associated with cognitive impairments. The aim of this study was to explore the relationship between cognitive subgroups in bipolar-schizophrenia spectrum disorders and telomere length against a healthy control sample., Methods: Participants included a transdiagnostic group diagnosed with bipolar, schizophrenia or schizoaffective disorder ( n = 73) and healthy controls ( n = 113). Cognitive clusters within the transdiagnostic patient group, were determined using K-means cluster analysis based on current cognitive functioning (MATRICS Consensus Cognitive Battery scores). Telomere length was determined using quantitative PCRs genomic DNA extracted from whole blood. Emergent clusters were then compared to the healthy control group on telomere length., Results: Two clusters emerged within the patient group that were deemed to reflect a relatively intact cognitive group and a cognitively impaired subgroup. Telomere length was significantly shorter in the severely impaired cognitive subgroup compared to the healthy control group., Conclusions: This study replicates previous findings of transdiagnostic cognitive subgroups and associates shorter telomere length with the severely impaired cognitive subgroup. These findings support emerging literature associating cognitive impairments in psychiatric disorders to accelerated cellular aging as indexed by telomere length.

Individuals with schizophrenia spectrum disorders (SSD) and a history of experiencing auditory verbal hallucinations (AVH) exhibit poor pitch discrimination relative to those with an SSD but no AVH history. The present study extended this research, asking if a lifetime history, and the current presence, of AVH exacerbated the pitch discrimination challenges that are seen in SSD. Participants completed a pitch discrimination task, where the tones presented differed in pitch by either 2 %, 5 %, 10 %, 25 % or 50 %. Pitch discrimination accuracy, sensitivity, reaction time (RT) and intra-individual RT variability (IIV) were examined in individuals with SSD and AVHs (AVH+; n = 46), or without AVHs (AVH-; n = 31), and healthy controls (HC; n = 131). Secondary analyses split the AVH+ group into state (i.e., actively experiencing AVH; n = 32) and trait hallucinators (i.e., a history of, but not actively experiencing, AVH; n = 16). Relative to HC, significantly poorer accuracy and sensitivity was detected in individuals with SSD at 2 % and 5 % pitch deviants, and in hallucinators at 10 %; however, no significant differences in accuracy, sensitivity, RT nor IIV were found between AVH+ and AVH- groups. No differences between state and trait hallucinators were observed. A general SSD deficit drove the current findings. The findings may inform future research into the auditory processing capabilities of AVH+ individuals., Competing Interests: Declaration of competing interest The authors have no conflicts of interest to declare., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Objectives: At least one in four persons with bipolar disorder (BD) are estimated to have experienced auditory verbal hallucinations (AVH) or heard voices at some point. Yet few studies have investigated AVH in detail in this population. This preliminary study examined the phenomenology of AVH in BD to identify commonalities and differences relative to other psychiatric disorders where AVH are commonly reported., Method: Twenty-one participants diagnosed with BD were recruited across two international sites in the UK and Australia. All participants underwent a structured clinical interview to verify psychiatric diagnosis and completed standardised measures of symptomatology, including mood states. Phenomenological information of AVH was gathered using select questions from the comprehensive Mental Health Research Institute Unusual Perceptual Schedule (MUPS)., Results: AVH experienced by this BD sample were broadly similar in form and content to characterisations reported in the schizophrenia spectrum disorders (SSD) in prior literature, with some exceptions including frequency, duration and the changeability of tone and content., Conclusions: The study highlights possibly subtle differences in the experience of AVH in BD, including the potential influence of mood congruence as a pertinent clinical feature. Further research into these differences might inform adaptations to existing AVH interventions to ensure they are relevant for BD., (© 2023 The Authors. Psychology and Psychotherapy: Theory, Research and Practice published by John Wiley & Sons Ltd on behalf of The British Psychological Society.)

Depression is a common and debilitating mental illness associated with sadness and negativity and is often comorbid with other psychiatric conditions, such as schizophrenia. Depressive symptoms are presently primarily assessed through clinical interviews, however there are other behavioural indicators being investigated as more objective methods of depressive symptom assessment. The present study aimed to evaluate the utility of assessing depression using quantitative speech parameters by comparing speech between 23 schizophrenia/schizoaffective patients with clinically significant depressive symptoms (DP) 19 schizophrenia/schizoaffective patients without depressive symptoms (NDP) and 22 healthy controls with no psychiatric history (HC). Participant audio recordings were transcribed and analyzed to extract five types of speech variables: utterances, words, speaking rate, formulation errors and pauses. The results indicated that DP patients produced significantly more pauses within utterances, and had more utterances with pauses compared to NDP patients and HCs (p = <.05), who performed similarly to each other. Word, speaking rate and formulation errors variables were not significantly different between the patient groups (p > .05). The findings suggest that depressive symptoms may have a specific relationship to speech pauses, and support the potential future use of speech pause assessments as an alternative and objective depression rating and monitoring tool., Competing Interests: Declaration of Competing Interest The authors declare that there are no conflicts of interest., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Cognitive performance is usually impaired in those with serious mental illness (SMI). Exercise may improve cognitive functioning, but studies examining the effects of exercise in SMI indicate heterogenous findings. To estimate the effects of exercise on cognitive outcomes in people with SMI. Randomized controlled trials evaluating the acute or chronic effects of exercise on cognitive functioning in SMI were searched from inception to December 26th, 2022 on major electronic databases. Random effect meta-analyses were conducted to assess the effects of exercise on over the cognitive domains and Standardized Mean Differences (SMD) and 95% confidence intervals (CIs) were used as the effect size measure. Funnel plots and Egger's test of effect size and the Trim and Fill procedure applied if evidence of publication bias was noted. Methodological quality was assessed using RoB 2. A total of 15 chronic (1 acute), 936 participants (46.7% women). Exercise showed large effects on reasoning and problem solving; small effects on executive functioning. Per diagnosis, exercise showed moderate positive effects on executive functioning and large effects on processing speed in people with depression; large effects on reasoning and problem solving in people with schizophrenia. The present study indicates a large beneficial effect of chronic physical exercise on reasoning and problem solving and small effects on executive functioning in people with SMI., Competing Interests: Declaration of Competing Interest No conflict declared., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Despite a growing body of research, there is yet to be a cohesive synthesis of studies examining differences in brain morphology according to patterns of cognitive function among both schizophrenia-spectrum disorder (SSD) and bipolar disorder (BD) individuals. We aimed to provide a systematic overview of the morphological differences-inclusive of grey and white matter volume, cortical thickness, and cortical surface area-between cognitive subgroups of these disorders and healthy controls, and between cognitive subgroups themselves. An initial search of PubMed and Scopus databases resulted in 1486 articles of which 20 met inclusion criteria and were reviewed in detail. The findings of this review do not provide strong evidence that cognitive subgroups of SSD or BD map to unique patterns of brain morphology. There is preliminary evidence to suggest that reductions in cortical thickness may be more strongly associated with cognitive impairment, whilst volumetric deficits may be largely tied to the presence of disease., (© 2022. The Author(s).)

Objectives: Neurocognitive deficits are central in schizophrenia. Cognitive remediation has proven effective in alleviating these deficits, with medium effect sizes. However, sizeable attrition rates are reported, with the reasons still uncertain. Furthermore, cognitive remediation is not part of routine mental health care. We conducted a systematic review to investigate factors that influence access and engagement of cognitive remediation in schizophrenia., Methods: We systematically searched the PubMed, Web of Science, and PsycINFO databases for peer-reviewed articles including a cognitive remediation arm, access, and engagement data, and participants with schizophrenia spectrum disorders aged 17-65 years old. Duplicates and studies without a distinct cognitive remediation component, protocol papers, single case studies, case series, and reviews/meta-analyses were excluded., Results: We included 67 studies that reported data on access and engagement, and extracted quantitative and qualitative data. Access data were limited, with most interventions delivered on-site, to outpatients, and in middle- to high-income countries. We found a median dropout rate of 14.29%. Only a small number of studies explored differences between dropouts and completers ( n  = 5), and engagement factors ( n  = 13). Dropouts had higher negative symptomatology and baseline self-efficacy, and lower baseline neurocognitive functioning and intrinsic motivation compared to completers. The engagement was positively associated with intrinsic motivation, self-efficacy, perceived usefulness, educational level, premorbid intelligence quotient, baseline neurocognitive functioning, some neurocognitive outcomes, and therapeutic alliance; and negatively associated with subjective cognitive complaints. Qualitative results showed good acceptability of cognitive remediation, with some areas for improvement., Conclusions: Overall, access and engagement results are scarce and heterogeneous. Further investigations of cognitive remediation for inpatients, as well as remote delivery, are needed. Future clinical trials should systematically explore attrition and related factors. Determining influential factors of access and engagement will help improve the implementation and efficacy of cognitive remediation, and thus the recovery of people with schizophrenia.

Considerable cognitive heterogeneity is present within the schizophrenia spectrum disorder (SSD) population. Several subgroups characterised by more homogenous cognitive profiles have been identified. It is not yet clear however, whether these subgroups represent different points along a continuum of cognitive symptom severity, or whether they reflect unique profiles of the disorder. One way to determine this is by comparing subgroups on their non-cognitive characteristics. The aim of the present review was to systematically summarise our current understanding of the non-cognitive features of the cognitive subgroups of schizophrenia spectrum disorder (SSD). Thirty-five relevant studies were identified from January 1980 to March 2020. Cognitive subgroups were consistently compared on age, sex, education, age of illness onset, illness duration, positive, negative and disorganised symptoms, depression and psychosocial functioning. It was revealed that subgroups were consistently distinguished by education, negative symptom severity and degree of functional impairment; with subgroups characterised by worse cognitive functioning performing/rated worse on these characteristics. The lack of consistent subgroup differences for the majority of the non-cognitive characteristics provides partial support for the notion that cognitive subgrouping in SSD is not simply reflecting a rehash of previously identified clinical subtypes. However, as subgroups were consistently distinguished by three characteristics known to be associated with cognition, our understanding of the extent to which the cognitive subgrouping approach is representing separate subtypes versus subdivisions along a continuum of symptom severity is still not definitive., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background and Hypothesis: Clozapine is the most effective antipsychotic for treatment-resistant schizophrenia, yet a significant proportion of individuals on clozapine continue to experience disabling symptoms, despite being treated with an adequate dose. There is a need for adjunct treatments to augment clozapine, notably for negative and cognitive symptoms. One such potential agent is the glutathione precursor N-acetylcysteine (NAC)., Study Design: A randomized double-blind, multi-center, placebo-controlled trial for clozapine patients with enduring psychotic symptoms (n = 84) was undertaken to investigate the efficacy of adjunctive NAC (2 g daily) for negative symptoms, cognition and quality of life (QoL). Efficacy was assessed at 8, 24, and 52 weeks., Study Results: NAC did not significantly improve negative symptoms (P = .62), overall cognition (P = .71) or quality of life (Manchester quality of life: P = .11; Assessment of quality of life: P = .57) at any time point over a 1-year period of treatment. There were no differences in reported side effects between the groups (P = .26)., Conclusions: NAC did not significantly improve schizophrenia symptoms, cognition, or quality of life in treatment-resistant patients taking clozapine. This trial was registered with "Australian and New Zealand Clinical Trials" on the 30 May, 2016 (Registration Number: ACTRN12615001273572)., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center.)

Different regions of the cortex have been implicated in the pathophysiology of schizophrenia. Recently published data suggested there are many more changes in gene expression in the frontal pole (Brodmann's Area (BA) 10) compared to the dorsolateral prefrontal cortex (BA 9) and the anterior cingulate cortex (BA 33) from patients with schizophrenia. These data argued that the frontal pole is significantly affected by the pathophysiology of schizophrenia. The frontal pole is a region necessary for higher cognitive functions and is highly interconnected with many other brain regions. In this review we summarise the growing body of evidence to support the hypothesis that a dysfunctional frontal pole, due at least in part to its widespread effects on brain function, is making an important contribution to the pathophysiology of schizophrenia. We detail the many structural, cellular and molecular abnormalities in the frontal pole from people with schizophrenia and present findings that argue the symptoms of schizophrenia are closely linked to dysfunction in this critical brain region., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest., (Copyright © 2022. Published by Elsevier B.V.)

It is suggested studying phenotypes within the syndrome of schizophrenia will accelerate understanding the complex molecular pathology of the disorder. Supporting this hypothesis, we have identified a sub-group within schizophrenia with impaired working memory (WM) and have used Affymetrix™ Human Exon 1.0 ST Arrays to compare their blood RNA levels (n=16) to a group of with intact WM (n=18). Levels of 72 RNAs were higher in blood from patients with impaired WM, 11 of which have proven links to the maintenance of different aspects of working memory (cognition). Overall, changed gene expression in those with impaired WM could be linked to cognition through glutamatergic activity, olfaction, immunity, inflammation as well as energy and metabolism. Our data gives preliminary support to the hypotheses that there is a working memory deficit phenotype within the syndrome of schizophrenia with has a biological underpinning. In addition, our data raises the possibility that a larger study could show that the specific changes in gene expression we have identified could prove to be the biomarkers needed to develop a blood test to identify those with impaired WM; a significant step toward allowing the use of personalised medicine directed toward improving their impaired working memory., Competing Interests: Competing Interests The authors have no competing interests to report., (Copyright © 2022. Published by Elsevier B.V.)

Objective: Suicide is a major cause of death amongst individuals with schizophrenia spectrum disorders (SSD). Despite numerous risk factors being identified, accurate prediction of suicidality and provision of tailored and effective treatment is difficult. One factor that may warrant particular attention as a contributor to increased psychopathology and suicidality in SSD is disturbed sleep. Sleep disturbances have been reliably linked to greater levels of suicidal ideation and are highly prevalent amongst individuals with SSD. This study aimed to examine if reduced sleep duration and psychopathology are associated with increased suicidal ideation., Method: One-hundred and eighteen adults with chronic SSD living within the community participated in this cross-sectional study. Psychosis symptoms were assessed using the Positive and Negative Syndrome Scale. Items 4 and 10 from the Montgomery-Asperg Depression Rating Scale and Item 2 from the Calgary Depression Scale for Schizophrenia were used to assess reduced sleep duration, current suicidal ideation, and hopelessness, respectively. All measures were rated concurrently., Results: A hierarchical logistic regression revealed that greater acute sleep disturbances were associated with increased suicidal ideation and this relationship was found to be uniquely mediated by both positive symptom severity and hopelessness., Conclusion: These results suggest that individuals with SSD who exhibited disrupted or disordered sleep, positive symptoms and/or hopelessness should be routinely screened for suicidal thinking. Furthermore, interventions that effectively target sleep disruptions may provide much-needed action against suicidal ideation.HIGHLIGHTSReduced sleep found to be associated with increased suicidal ideationThis was uniquely mediated by both hopelessness and positive symptomsMore regular screening of sleep problems in schizophrenia is needed.

Hallucinations and delusions in borderline personality disorder (BPD) are understudied. The authors explore the phenomenology of multisensory hallucinations and delusions in individuals with BPD and compare them to those in individuals with schizophrenia spectrum disorders (SSD). Clinical psychopathology was also explored. Eighty-nine adults participated and were categorized into four groups: BPD with voices, BPD without voices, SSD with high BPD traits, and SSD with low BPD traits. Among individuals with BPD, 81% reported visual and tactile hallucinations, 75% reported olfactory hallucinations, and 94% experienced delusions. When comparing BPD with and without voices, there were no significant differences in nonpsychotic psychopathology. Slight differences were found when hallucinations in BPD were compared with hallucinations in SSD, but overall the experiences were similar across diagnoses. The BPD group also reported significantly higher rates of paranoia/suspiciousness and delusions of guilt than the SSD group. Multisensory hallucinations and delusions occur in BPD and should be explored when treating people with BPD.

Background: Earlier schizophrenia onset in men relative to women has been a consistent finding in the literature, but a nuanced understanding of underlying reasons remains elusive. Further consideration should be given to factors associated with sex differences in age of onset., Method: Participants with schizophrenia were derived from the 2010 Australian Survey of High Impact Psychosis (n = 857). The SHIP survey constituted a representative, population-based study of almost 1.5 million Australian adults seen at various mental health services, and assessed personal health information, psychiatric comorbidities as well as psychosis illness and treatment. Hierarchical clustering was employed to identify age of onset by sex. Within-sex comparisons on distal and proximal factors affecting age of onset were conducted., Results: Using modal age, two and three clusters were respectively found in men (early versus late onset) and women (early versus mid versus late onset). Early onset groups in both sexes had an increased family history of psychosis compared to older onset, but other risk factors were not consistent across the sexes. Less premorbid impairment was noted in females with middle to later onset schizophrenia., Conclusion: These findings further inform our understanding of the pathogenesis of schizophrenia. Added explorations of trends in older onset schizophrenia cohorts is especially important., (Crown Copyright © 2022. Published by Elsevier Ltd. All rights reserved.)

Sex differences in symptoms and executive control across schizophrenia spectrum disorders (SSD) are consistently reported. Similarly, these findings of sex differences are also observed in schizotypy, that is, schizophrenia-like features occurring in healthy individuals in the absence of a clinical diagnosis. This study aimed to examine the relationships between performance on three major domains of executive control: performance monitoring, response inhibition, and cognitive set-shifting, and schizotypy factor scores in both SSD patients and healthy controls (HCs), and whether sex moderated any relationships observed. A total of 111 (67 males and 44 females) patients with SSD and 258 (129 males and 129 females) HCs were included in this study. Schizotypal personality traits (in both SSD and HC) was assessed using the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE). Executive control performance was assessed using seven tasks. Stepwise linear regressions revealed that performance on cognitive set-shifting tasks was significantly associated with the introvertive anhedonia, cognitive disorganisation, and unusual experiences subscales of the O-LIFE. When sex was examined as a moderator, it was not a significant moderator of any of the relationships between cognitive set-shifting tasks and schizotypy factors. The results suggest that independent of sex, cognitive set-shifting ability is associated to an increased vulnerability to schizotypal personality traits, although performance monitoring and response inhibition did not., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Positive and negative symptoms are core aspects of schizophrenia and have been shown to influence patient quality of life (QOL). Previous studies have largely focused on current or state symptoms, with limited work on the contributions of trait symptoms to QOL. This study sought to examine the relationship between both state and trait symptoms and objective and subjective QOL. Fifty-three schizophrenia spectrum disorder patients and 47 healthy controls were recruited. State symptomatology was assessed using the Positive and Negative Syndrome Scale in the patients only. In all participants, trait symptoms were assessed using the Oxford-Liverpool Inventory of Feelings and Experiences, and QOL using Lehman's QOL Interview. Hierarchical linear regression analyses, controlling for depression and neurocognition, revealed that negative state symptoms were related to objective QOL within the patients, while negative trait symptoms were associated with both objective and subjective QOL in patients and healthy controls. No relationships were observed with positive state or trait symptoms and either QOL measure. The findings suggest a degree of complexity in the associations between symptoms and QOL, with primacy for negative symptoms at both state and trait levels. A greater appreciation of trait symptoms may help explain non-complementary QOL changes following symptom remission., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Speech disturbances are a recognised aspect of schizophrenia that may have potential utility as a diagnostic indicator. Recent advances in quantitative speech assessment methods have led to more reproducible and precise metrics making this possible. The current study sought firstly to characterise the speech profile of schizophrenia patients using quantitative speech measures, then examine the diagnostic utility of these measures and explore their relationship to symptoms., Methods: Speech recordings from 43 schizophrenia/schizoaffective disorder (SZ) patients and 46 healthy controls (HC) were obtained and transcribed. Cognitive and symptom measures were also administered., Results: Compared to HCs, SZ patients had higher incidences of aberrance across five types of quantitative speech variables: utterances, single words, time/speaking rate, turns and formulation errors, but not pauses. Based on two machine learning algorithms, 21 speech variables across the same five speech variable types (again not including pauses) were identified as significant classifiers for a schizophrenia diagnosis with 90-100% specificity and 80-90% sensitivity for both models. Selective relationships were also observed between these speech variables and only positive, disorganisation, excitement and formal thought disorder symptoms., Conclusions: The findings support pervasive speech impairments in schizophrenia patients relative to HCs, and the potential diagnostic utility of these speech disturbances. Continued work is needed to build the evidence base for quantitative speech assessment as a future objective diagnostic tool for schizophrenia. It holds the promise of improved diagnostic accuracy leading to increased treatment efficacy and better patient outcomes., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The nature of the relationship between cognition and brain morphology in schizophrenia-spectrum disorders (SSD) and bipolar disorder (BD) is uncertain. This review aimed to address this, by providing a comprehensive systematic investigation of links between several cognitive domains and brain volume, cortical thickness, and cortical surface area in SSD and BD patients across early and established illness stages. An initial search of PubMed and Scopus databases resulted in 1486 articles, of which 124 met inclusion criteria and were reviewed in detail. The majority of studies focused on SSD, while those of BD were scarce. Replicated evidence for specific regions associated with indices of cognition was minimal, however for several cognitive domains, the frontal and temporal regions were broadly implicated across both recent-onset and established SSD, and to a lesser extent BD. Collectively, the findings of this review emphasize the significance of both frontal and temporal regions for some domains of cognition in SSD, while highlighting the need for future BD-related studies on this topic., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objective: There is ongoing debate regarding the relationship between clinical symptoms and cognition in schizophrenia spectrum disorders (SSD). The present study aimed to explore the potential relationships between symptoms, with an emphasis on negative symptoms, and social and non-social cognition., Method: Hierarchical cluster analysis with k-means optimisation was conducted to characterise clinical subgroups using the Scale for the Assessment of Negative Symptoms and Scale for the Assessment of Positive Symptoms in n = 130 SSD participants. Emergent clusters were compared on the MATRICS Consensus Cognitive Battery, which measures non-social cognition and emotion management as well as demographic and clinical variables. Spearman's correlations were then used to investigate potential relationships between specific negative symptoms and emotion management and non-social cognition., Results: Four distinct clinical subgroups were identified: 1. high hallucinations, 2. mixed symptoms, 3. high negative symptoms, and 4. relatively asymptomatic. The high negative symptom subgroup was found to have significantly poorer emotion management than the high hallucination and relatively asymptomatic subgroups. No further differences between subgroups were observed. Correlation analyses revealed avolition-apathy and anhedonia-asociality were negatively correlated with emotion management, but not non-social cognition. Affective flattening and alogia were not associated with either emotion management or non-social cognition., Conclusions: The present study identified associations between negative symptoms and emotion management within social cognition, but no domains of non-social cognition. This relationship may be specific to motivation, anhedonia and apathy, but not expressive deficits. This suggests that targeted interventions for social cognition may also result in parallel improvement in some specific negative symptoms.

Individuals with schizophrenia spectrum disorders (SSD) experience frequent sleep disturbances in addition to enduring cognitive impairments. The purpose of the present review was to systematically summarise our current understanding of the association between sleep disturbances and cognition in SSD. Through this, it was aimed to identify features of disturbed sleep that are reliably associated with cognitive deficits in SSD and identify the gaps within the current literature that require future investigation. Eighteen relevant studies were identified following a two-stage screening process. Following a structured narrative synthesis of key study components, no clear and consistent pattern emerged. Considerable methodological variability was present amongst the reviewed studies. Although some broad consistencies were identified, such as associations between sleep spindle density and sleep-dependent memory consolidation, the overall pattern of results lacked a cohesive composition due to the diverse list of sleep parameters and cognitive domains investigated, as well as a lack of replication. Additional research is needed before more definitive remarks can be made regarding the influence of sleep disturbances on cognitive function in SSD., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Characterisation of brain morphological features common to cognitively similar individuals with bipolar disorder (BD) and schizophrenia spectrum disorders (SSD) may be key to understanding their shared neurobiological deficits. In the current study we examined whether three previously characterised cross-diagnostic cognitive subgroups differed among themselves and in comparison to healthy controls across measures of brain morphology., Method: T1-weighted structural magnetic resonance imaging scans were obtained for 143 individuals; 65 healthy controls and 78 patients (SSD, n = 40; BD I, n = 38) classified into three cross-diagnostic cognitive subgroups: Globally Impaired (n = 24), Selectively Impaired (n = 32), and Superior/Near-Normal (n = 22). Cognitive subgroups were compared to each other and healthy controls on three separate analyses investigating (1) global, (2) regional, and (3) vertex-wise comparisons of brain volume, thickness, and surface area., Results: No significant subgroup differences were evident in global measures of brain morphology. In region of interest analyses, the Selectively Impaired subgroup had greater right accumbens volume than those Superior/Near-Normal subgroup and healthy controls, and the Superior/Near-Normal subgroup had reduced volume of the left entorhinal region compared to all other groups. In vertex-wise comparisons, the Globally Impaired subgroup had greater right precentral volume than the Selectively Impaired subgroup, and thicker cortex in the postcentral region relative to the Superior/Near-Normal subgroup., Limitations: Exploration of medication effects was limited in our data., Conclusions: Although some differences were evident in this sample, generally cross-diagnostic cognitive subgroups of individuals with SSD and BD did not appear to be clearly distinguished by patterns in brain morphology., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: In people with schizophrenia, self-efficacy (i.e. the belief in one's capability to perform particular tasks/skills) is associated with and motivates performance of social, health and independent living behaviours. Less well known is whether self-efficacy is associated with subjective quality of life (sQoL) or whether psychopathology impacts this relationship., Aims: Measure whether greater self-efficacy is associated with greater community functioning and sQoL and whether emotional discomfort mediates this relationship., Method: Fifty-two community living people with schizophrenia completed measures of self-efficacy for everyday living and social situations, clinical symptoms, sQoL and community functioning., Results: Greater everyday living and social self-efficacy was significantly correlated with greater sQoL and community functioning and lower emotional discomfort ( p  < 0.05). Only social self-efficacy was correlated with negative symptoms. The relationship between both aspects of self-efficacy and sQoL was, however, mediated by emotional discomfort. Greater confidence in performing social and everyday living behaviours therefore indirectly impacted sQoL through reducing emotional distress., Conclusions: Holding negative capability self-beliefs may contribute to poorer outcome for people with schizophrenia. Intervention aimed at facilitating recovery should therefore provide opportunities to develop knowledge and skills required for success in desired life roles and the belief that tasks required for success can be performed.

Objective: Data from the 2010 Australian National Survey of High Impact Psychosis (SHIP) was used to examine (1) what variables influence age of onset (AOO) for males and females, and (2) whether influencing variables were different between the sexes., Method: Data from 622 schizophrenia patients in the SHIP sample was used. These included early life factors, encompassing family psychiatric history, childhood development, trauma and parental loss. Factors occurring within 12 months of diagnosis were also used, including drug/alcohol abuse and premorbid work and social adjustment. Based on the recognised differences in symptom profiles and AOO between the sexes, these factors were regressed separately for males and females., Results: Stepwise linear regressions showed that a family history of psychiatric disorders was significantly associated with earlier AOO in both sexes. Other variables differed between males and females. Specifically, for females, an earlier AOO was associated with poor premorbid social adjustment and the loss of a family member in childhood. Older AOO was associated with immigrant status. For males, a younger AOO was associated with unemployment at onset, poor premorbid work adjustment, parental divorce in childhood, and lifetime cannabis use. A higher premorbid IQ was associated with an older AOO., Conclusion: Familial predisposition to psychiatric illness is related to earlier AOO of schizophrenia independent of sex. Males appear to have more individual-based predictive factors while females seem to have more community/social-based influences. Future directions for research in schizophrenia are suggested., Competing Interests: Declaration of competing interest The author(s) declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Phenomenological comparisons of auditory verbal hallucinations (AVHs) in affective versus non-affective psychosis have not been adequately documented. The current study aimed to: a) comprehensively describe AVH phenomenology by diagnosis and mood state, b) investigate significant predictors of voice-related distress and functional impairment, and c) conduct qualitative thematic analysis of participants' experiences. Participants were diagnosed with: a) bipolar disorder (n = 31), b) major depressive disorder (n = 34), c) schizophrenia (n = 50), or d) schizoaffective disorder (n = 26). Current voice-hearers were also subdivided into prevailing mood states: a) euthymic (n = 23), b) depressed (n = 51), or c) mania-mixed (n = 12). An in-depth, semi-structured interview was conducted, accompanied by mixed-methods analyses. Of the 34 AVH characteristics, significant group differences across diagnoses were identified only for frequency, number of voices, form of address, perceived location, level of conviction, beliefs regarding origin, and functional interference. Random forests modelling (RFM) showed experienced distress and functional interference were best predicted by discrete AVH variables. Qualitative thematic analysis revealed first-order themes: a) content, b) form, c) function, and d) non-voice. There were more similarities than differences in the phenomenology of AVHs across diagnoses, yet significant predictors of voice-related distress and functional impairment differed across affective and non-affective psychosis. This has important nosological and therapeutic applications., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)

When measured from the perspective of a clinician, the severity of 'objective' thought disorder (TD) has been found to vary continuously between people with and without psychosis-related diagnoses, and has been linked with semantic and executive dysfunctions in people with psychosis. Measures of 'subjective' TD that are derived from a first-person perspective have also been produced, but their relationships with objective TD and cognition are unclear. The aims of the current study were: to determine whether responses on a self-report TD questionnaire correspond with responses to a self-report measure of schizotypal disorganization; and to explore the association between these self-reported subjective TD severities and cognitive performance. Data was collected from a sample of 33 people without psychiatric diagnoses and 38 people diagnosed with schizophrenia or schizoaffective disorder evincing mild symptomatology, and this data was pooled for analysis in accordance with the continuum model. Self-reported TD frequencies were associated with the endorsement of disorganized schizotypal experiences. Moreover, self-reported TD frequencies showed relationships with measures of semantic and executive functioning. Thus, at mild severities, self-reported TD shows continuous variation and is associated with altered cognitive function., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objective: There is accumulating evidence that adjunctive treatment with N -acetylcysteine may be effective for schizophrenia. This study aimed to conduct a comprehensive meta-analysis examining the efficacy of randomised control trials investigating N -acetylcysteine as an adjunct treatment for schizophrenia and the first to investigate cognition as an outcome., Methods: We systematically reviewed Medline, EmCare, PsycINFO, Embase, CINAHL Complete, China Knowledge Resource Integrated Database and the Cochrane Clinical Trials online registry for randomised control trials of N -acetylcysteine for schizophrenia. We undertook pairwise meta-analyses of N -acetylcysteine vs placebo for psychosis symptoms and cognition., Results: Seven studies, including n = 220 receiving N -acetylcysteine and n = 220 receiving placebo, met inclusion criteria for the pairwise meta-analyses. Positive and Negative Syndrome Scale negative and total scores were significantly improved in the N -acetylcysteine group after 24 weeks of treatment. The cognitive domain of working memory improved with N -acetylcysteine supplementation., Conclusion: Evidence supports the notion that N -acetylcysteine may be a useful adjunct to standard treatment for the improvement of schizophrenia symptoms, as well as the cognitive domain of working memory. Treatment effects were observed at the later time point (⩾24 weeks), suggesting that longer interventions are required for the success of N -acetylcysteine treatment.

Background: Cognitive heterogeneity in schizophrenia spectrum disorders (SSD) and bipolar disorder (BD) has been explored using clustering analyses. However, the resulting subgroups have not been cognitively validated beyond measures used as clustering variables themselves. We compared the emergent cross-diagnostic subgroups of SSD and BD patients on measures used to classify them, and also across a range of alternative cognitive measures assessing some of the same constructs., Method: Domain scores from the Matrics Consensus Cognitive Battery were used in a cross-diagnostic clustering analysis of 86 patients with SSD (n = 45) and BD (n = 41). The emergent subgroups were then compared to each other and healthy controls (n = 76) on these and alternative measures of these domains, as well as on premorbid IQ, global cognition and a proxy of cognitive decline., Results: A three-cluster solution was most appropriate, with subgroups labelled as Globally Impaired, Selectively Impaired, and Superior/Near-Normal relative to controls. With the exception of processing speed performance, the subgroups were generally differentiated on the cognitive domain scores used as clustering variables. Differences in cognitive performance among these subgroups were not always statistically significant when compared on the alternative cognitive measures. There was evidence of global cognitive impairment and putative cognitive decline in the two cognitively impaired subgroups., Limitations: For clustering analysis, sample size was relatively small., Conclusions: The overall pattern of findings tentatively suggest that emergent cross-diagnostic cognitive subgroups are not artefacts of the measures used to define them, but may represent the outcome of different cognitive trajectories., Competing Interests: Declaration of Competing Interest Over the last four years, Prof Pantelis has been on advisory boards for AstraZeneca, Janssen-Cilag, Lundbeck, and Servier; and he has received honoraria for talks presented at educational meetings organized by AstraZeneca, Eli Lilly, Janssen-Cilag, Lundbeck, Pfizer, and Shire. The other authors report no financial relationships with commercial interests., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The prevailing nosological classification of body dysmorphic disorder (BDD) encompasses an optional specifier "with absent insight/delusional beliefs" for patients who hold high conviction of the veracity of their disorder-specific beliefs. Yet limited research has examined the explicit nature of delusional beliefs in BDD. The current study therefore aimed to compare themes of delusional ideation in BDD relative to schizophrenia (SCZ) and healthy controls (HCs). Participants had a primary diagnosis of BDD (n = 44) or SCZ (n = 55), or were HCs (n = 55) with no personal or immediate family history of a diagnosable mental health disorder. Assessment of multidimensional delusional ideation was based on the Peters Delusional Inventory (PDI). Results showed that BDD and SCZ groups endorsed significantly more items, and had significantly elevated preoccupation and conviction than the HC group. Only the SCZ group exhibited significantly elevated distress relative to HC participants. In addition, BDD (akin to SCZ) participants were more likely to endorse somatic (appearance-related), control and thought alienation themes than the HC group. These findings suggest that delusional beliefs in BDD may not be strictly appearance-related, but rather span broader themes. This conveys therapeutic implications in terms of designing and administering targeted treatments aimed at delusional thinking in BDD., Competing Interests: Declaration of Competing Interest The author declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objectives: Schizophrenia is a debilitating psychiatric illness associated with positive and negative symptoms as well as significant impairments in cognition. Current antipsychotic medications do not alleviate these cognitive deficits, and more effective therapeutic options are required. Increased oxidative stress and altered antioxidant levels, including glutathione (GSH) have been observed both in individuals with cognitive impairment and in people with schizophrenia. A GSH precursor, the antioxidant N -acetylcysteine (NAC) has been investigated as a novel treatment for the cognitive symptoms of schizophrenia, and recent research suggests that NAC may be a promising adjunctive treatment option. However, the current literature lacks integration as to why NAC may effectively improve cognition in schizophrenia. The present theoretical synthesis aimed to address this gap by examining the processes by which NAC may improve cognitive function in schizophrenia. Methods: The schizophrenia literature was reviewed in three key domains: cognitive impairment, the relationship between oxidative stress and cognition, and the efficacy of NAC as a novel treatment. This led to a theoretical analysis of the neurobiological processes by which NAC may improve cognition in schizophrenia. Results: This theoretical review concluded that improved cognition may result from a combination of factors, including decreased oxidative stress, neuroprotection of cognitive networks and an increase in glutamatergic modulation of the N -methyl-d-aspartate receptor system. Whilst a number of mechanisms by which NAC may improve cognition and symptoms in schizophrenia have been proposed, there is still limited understanding of the specific metabolic pathways involved and how they interrelate and modify specific symptomology. Discussion: Exploration of how NAC treatment may act to improve cognitive function could guide clinical trials by investigation of the specific neurotransmitter systems and processes involved, allowing for targeted neurological outcome measures. Future research would benefit from the investigation of both in vivo cortical GSH concentration and peripheral plasma GSH in a population of individuals with chronic schizophrenia.

Background: People with schizophrenia frequently have cognitive dysfunction, which does not respond to pharmacological interventions. Varenicline has been identified as a potential treatment option for nicotinic receptor dysfunction with a potential to treat cognitive impairment in schizophrenia., Methods: We conducted a systematic review of Pubmed, Embase, Psycinfo, CINAHL and the Cochrane Schizophrenia Trial Registry for randomised controlled trials of varenicline in people with schizophrenia for cognitive dysfunction. We excluded trials among people with dementia. We then undertook a meta-analysis with the primary outcome of difference in change of cognitive measures between varenicline and placebo as well as secondary outcomes of difference in rates of adverse events. We conducted a sensitivity analysis on smoking status and study duration., Results: We included four papers in the meta-analysis (n = 339). Varenicline was not superior to placebo for overall cognition (SMD = -0.022, 95% CI -0.154-0.110; Z = -0.333; p = 0.739), attention (SMD = -0.047, 95% CI -0.199-0.104; Z = -0.613; p = 0.540), executive function (SMD = -0.060, 95% CI -0.469-0.348; Z =- 0.290; p = 0.772) or processing speed (SMD = 0.038, 95% CI -0.232-0.308; Z = 0.279; p = 0.780). There was no difference in psychotic symptoms, but varenicline was associated with higher rates of nausea. Sensitivity analyses for smoking status and study duration did not alter the results., Conclusion: Within the present literature, varenicline does not appear to be a useful target compound for improving cognitive impairment in schizophrenia. Based on these results, a trial would need over 2500 participants to be powered to show statistically significant findings.

The aim of the present review was to systematically summarise our current understanding of the structure of the cognitive heterogeneity that exists within schizophrenia spectrum disorder (SSD). Fifty-two relevant studies were identified from January 1980 to March 2019 that investigated cognitive subgroups within SSD. Twenty-five studies employed classification criteria based on current neuropsychological function, 14 studies employed various data-driven subgrouping methodologies and 13 studies investigated putative cognitive symptom trajectories. Despite considerable methodological variability, three distinct cognitive subgroups reliability emerged; a relatively intact cognitive subgroup characterised by high cognitive performance, an intermediate cognitive subgroup defined by mixed or moderate levels of cognitive function/dysfunction and a globally impaired subgroup characterised by severe cognitive deficits. Whilst preliminary evidence suggests that these subgroups may have further investigative relevance in and of themselves, additional research is required and discussed. A set of reporting guidelines are also presented to overcome the methodological inconsistencies identified in the reviewed literature., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Scant research attention has been devoted to the phenomenon of multimodal hallucinations, with majority of studies focusing on auditory hallucinations (AH) in psychosis. The current study aimed to explore the frequency and characteristics of these multisensory hallucinations in a primary AH cohort. It was concluded more than half of our sample reported comorbid hallucinations in one or more sensory modes. This conveys significant research and clinical implications, in terms of steps taken for adequate assessment and intervention., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objectives: The Wisconsin Card Sorting Test (WCST) is a complex measure of executive function that is frequently employed to investigate the schizophrenia spectrum. The successful completion of the task requires the interaction of multiple intact executive processes, including attention, inhibition, cognitive flexibility, and concept formation. Considerable cognitive heterogeneity exists among the schizophrenia spectrum population, with substantive evidence to support the existence of distinct cognitive phenotypes. The within-group performance heterogeneity of individuals with schizophrenia spectrum disorder (SSD) on the WCST has yet to be investigated. A data-driven cluster analysis was performed to characterise WCST performance heterogeneity., Methods: Hierarchical cluster analysis with k-means optimisation was employed to identify homogenous subgroups in a sample of 210 schizophrenia spectrum participants. Emergent clusters were then compared to each other and a group of 194 healthy controls (HC) on WCST performance and demographic/clinical variables., Results: Three clusters emerged and were validated via altered design iterations. Clusters were deemed to reflect a relatively intact patient subgroup, a moderately impaired patient subgroup, and a severely impaired patient subgroup., Conclusions: Considerable within-group heterogeneity exists on the WCST. Identification of subgroups of patients who exhibit homogenous performance on measures of executive functioning may assist in optimising cognitive interventions. Previous associations found using the WCST among schizophrenia spectrum participants should be reappraised. (JINS, 2019, 25, 750-760).

Objective: Cognitive remediation therapy is a moderately effective intervention for ameliorating cognitive deficits in individuals with schizophrenia-related disorders. With reports of considerable variability in individual response to cognitive remediation therapy, we need to better understand factors that influence cognitive remediation therapy efficacy to realise its potential. A systematic review was conducted to identify and evaluate predictors of cognitive outcome., Methods: An electronic database search was conducted identifying peer-reviewed articles examining predictors of cognitive response to cognitive remediation therapy., Results: A total of 40 articles accounting for 1681 cognitive remediation therapy participants were included; 81 distinct predictors of cognitive response were identified. Data synthesis and discussion focused on 20 predictors examined a minimum three times in different studies. Few of the examined predictors of cognitive outcome following cognitive remediation therapy were significant when examined through systematic review. A strong trend was found for baseline cognition, with reasoning and problem solving and working memory being strongly predictive of within-domain improvement. Training task progress was the most notable cross-domain predictor of cognitive outcome., Conclusion: It remains unclear why a large proportion of participants fail to realise cognitive benefit from cognitive remediation therapy. However, when considering only those variables where a majority of articles reported a statistically significant association with cognitive response to cognitive remediation therapy, three stand out: premorbid IQ, baseline cognition and training task progress. Each of these relates in some way to an individual's capacity or potential for change. There is a need to consolidate investigation of potential predictors of response to cognitive remediation therapy, strengthening the evidence base through replication and collaboration.

Individuals with schizophrenia who are homozygous at the c.267C > A (rs2067477) single nucleotide polymorphism within the muscarinic M1 receptor gene have been reported to perform less well on the Wisconsin Card Sorting Test (WCST). We investigated if rs2067477 genotype variation influenced WCST performance and non-executive cognition cross-diagnostically in a sample of 147 schizophrenia spectrum participants (SSD) and 294 healthy controls. We were unable to detect any significant differences in executive and non-executive cognitive performance across genotype. A broader genetic focus should be considered when investigating the association between the muscarinic system and cognition in SSD., (Crown Copyright © 2019. Published by Elsevier B.V. All rights reserved.)

Background: A prominent area of advancement in the psychological treatment for people with persisting psychosis has been the application of mindfulness-based therapies. Recent literature has recommended the investigation of focused mindfulness interventions for voices (auditory hallucinations) as a specific experience. To date, only mindfulness programs in group format have been examined., Aims: This non-randomized pilot study aimed to assess the acceptability, feasibility and potential outcomes of an individual mindfulness program for persistent voices on the negative impact of voices on the subjective experience of mental health and wellbeing, depression and voice-related distress and disruption. Also, it aimed to identify potential psychological and neurocognitive mechanisms of change., Method: A new 4-week individual Mindfulness Program for Voices (iMPV) was developed, and piloted with a group of 14 participants with a schizophrenia-spectrum disorder and persisting voices. Participants completed clinical and neurocognitive measures pre- and post-intervention and at 2-month follow-up., Results: Results revealed low attrition rates, high formal practice engagement levels and positive participant feedback. Pre-post outcomes suggested small to moderate effects for a reduction in the negative impact of voices on experience, depression and disruption. Large effects for changes in mindful responding and attentional switching were also identified., Conclusions: Our findings suggest that this novel treatment protocol is appropriate, engaging and safe for persistent voice hearers. Findings for mindful responding and attentional switching suggest these to be potential mechanisms of change for further investigation. Further RCTs are warranted to ascertain the feasibility and efficacy for focused mindfulness interventions for voices of individual format.

Objective: The personality characteristics and symptoms observed in schizophrenia are postulated to lie on a continuum, with non-clinical manifestations referred to as schizotypy. High schizotypy behaviours are argued to correspond with the three main clusters of symptoms in schizophrenia: positive, negative and cognitive/disorganised symptoms, yet there is limited empirical evidence to support this. This study aimed to investigate whether schizotypy dimensions significantly correlate with their respective schizophrenia symptomatology in the largest sample to date., Methods: A total of 361 adults (103 patients with schizophrenia/schizoaffective disorder and 258 healthy controls) were assessed for schizotypy using the Oxford-Liverpool Inventory of Feelings and Experiences. The MATRICS Consensus Cognitive Battery supplemented by the Stroop task and Wisconsin Card Sorting Test was administered to all participants to obtain objective measurements of cognition. Schizophrenia symptomatology was assessed using the Positive and Negative Syndrome Scale in patients only., Results: The results demonstrated significant correlations between the Oxford-Liverpool Inventory of Feelings and Experiences positive and negative subscales and their respective Positive and Negative Syndrome Scale subscales only, indicating that positive and negative schizotypy dimensions across patients and controls accurately reflect the respective schizophrenia symptomatology observed in patients. Cognitive performance did not correlate with cognitive/disorganised symptom dimensions of the Oxford-Liverpool Inventory of Feelings and Experiences or the Positive and Negative Syndrome Scale, indicating that cognitive impairment is an independent symptom dimension that requires objective cognitive testing., Conclusion: Collectively, the findings provide empirical evidence for the continuum theory and support the use of schizotypy as a model for investigating schizophrenia.

Delusions are a core feature of psychopathology while fantasy proneness (FP) is a trait that describes a predisposition towards fantastical thinking, vivid mental imagery and an overactive imagination. The relationship between FP and delusional experiences has not yet been examined in the literature. The current study hypothesised that FP would be significantly associated with and predict delusion severity as well as the associated delusional distress, preoccupation and conviction. Ninety-five patients with current psychosis (schizophrenia and bipolar I disorder) were assessed for overall delusional severity using the PANSS (clinician-rated) and the Peters Delusions Inventory (PDI; self-report). FP was assessed using the Creative Experiences Questionnaire (CEQ). Forty-six healthy control participants also completed the PDI and CEQ. Significant positive correlations were observed between FP and delusion severity in both groups; and distress, preoccupation and conviction in patients only. Linear regression analyses, controlling for manic and depressive symptoms, revealed that greater FP predicted higher levels of severity, distress, preoccupation, and conviction associated with delusions in patients, and higher severity only in healthy controls. The findings highlight the role of specific cognitive biases in delusional experiences, and empirically support models of unusual belief formation and maintenance., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Psychotic experiences are prevalent across a wide variety of psychiatric, neurological, and medical conditions. Yet current assessments are often designed for one disorder, or are limited in their examination of phenomenological features; this has hindered transdiagnostic research. This article describes an examination of the validity and reliability of the English version of a new assessment, the Questionnaire for Psychotic Experiences (QPE). This study aimed to use the QPE to examine hallucinations and delusions across a number of different conditions, and to ensure that the QPE had acceptable psychometric properties. An International Consortium on Hallucination Research working group, along with consumer groups, developed the 50-item QPE to assess the presence, severity, and phenomenology of hallucinations and delusions. Participants in the study who reported psychotic experiences included those with schizophrenia, schizoaffective disorder, bipolar affective disorder, and major depressive disorder, and those without a need for care (ie, nonclinical participants). There were 173 participants in total. Convergent and discriminant validity were assessed. Reliability was examined in terms of stability, equivalence, and internal consistency. The data confirmed that the QPE had good psychometric properties and could be put forward as an accepted measure of the transdiagnostic evaluation of psychotic experiences. Further validation is recommended with neurological and medical populations. Given its validity and reliability, comprehensive evaluation of psychotic phenomena, and relatively quick administration time, we propose that the QPE is a valuable instrument for both clinical and research settings.