Neuropsychological function and dysfunction in schizophrenia and psychotic affective disorders

Predictive value of premorbid IQ, negative symptoms, and age for cognitive and social functions in Japanese patients with schizophrenia: A study using the Japanese version of the Brief Assessment of Cognition in Schizophrenia

Enduring cognitive impairment in patients with schizophrenia represents a global health burden. The Japanese-language version of the Brief Assessment of Cognition in Schizophrenia (BACS) and the Japanese Adult Reading Test were administered to 288 patients with chronic schizophrenia and 308 unrelated healthy control subjects. The Japanese version of self-reported Social Functioning Scale (SFS) was administered to a subpopulation of 157 patients with schizophrenia. In patients with schizophrenia, premorbid IQ and age were significantly related to most of the BACS subdomains, composite score, and intra-individual variability of BACS subdomains, whereas negative symptoms were significantly related to all BACS indices. Dosages of the first-generation antipsychotics had a significant negative impact on Tower of London task and intra-individual variability of BACS subdomains. The relationship of symbol coding with age was significantly lower in patients than in healthy control subjects. Multiple regression analysis revealed that negative symptoms were significantly negatively related to the total SFS scale, whereas better performance of token motor task was associated with higher total SFS. The present study revealed the role of premorbid IQ, age, and negative symptoms in predicting cognitive performance, and the significant correlation of negative symptoms and token motor task with social function in patients with schizophrenia.

Systematic review of randomized controlled trials of candidate treatments for cognitive impairment in depression and methodological challenges in the field

Cognitive impairment is a core feature of Major Depressive Disorder (MDD) but treatments targeting cognition are lacking. Numerous pre-clinical and clinical studies have investigated potential cognition treatments, but overall the evidence is conflicting. We conducted a systematic search following the PRISMA guidelines on PubMed and PsychInfo to evaluate the extant evidence and methodological challenges in randomized controlled trials (RCTs) of biological, psychological and behavioural candidate treatments targeting cognition in MDD. Inclusion criteria were RCTs with a placebo control assessing potential pro-cognitive effects of candidate treatments in MDD. Two independent authors reviewed the studies and assessed their risk of bias with the Cochrane Collaboration׳s Risk of Bias tool. Twenty-eight eligible studies (24 biological and four psychological or behavioural studies) were identified. Cognition was the primary treatment target in ten (36%) trials and an additional treatment outcome together with mood symptoms in 18 (64%) trials. The risk of bias was high or unclear in 93% of trials due to potential selective outcome reporting or 'pseudospecificity' (unspecific cognitive improvement due to reduced depression severity), and/or insufficient details on how the allocation sequence was generated or how blinding was maintained. Several promising treatments were identified, including vortioxetine, erythropoietin, transcranial direct current stimulation and cognitive remediation. However, several common methodological challenges may impede advances in the field. In particular, future trials should select one cognitive composite score as primary outcome, screen for cognitive impairment before inclusion of participants and address 'pseudospecificity' issues. Together, these strategies may improve the success of future cognition trials in MDD.

Discrete neurocognitive subgroups in fully or partially remitted bipolar disorder: Associations with functional abilities

BACKGROUND

Neurocognitive impairment in remitted patients with bipolar disorder contributes to functional disabilities. However, the pattern and impact of these deficits are unclear.

METHODS

We pooled data from 193 fully or partially remitted patients with bipolar disorder and 110 healthy controls. Hierarchical cluster analysis was conducted to determine whether there are discrete neurocognitive subgroups in bipolar disorder. The pattern of the cognitive deficits and the characteristics of patients in these neurocognitive subgroups were examined with analyses of covariance and least significance difference pairwise comparison.

RESULTS

Three discrete neurocognitive subgroups were detected: one that was cognitively intact (46.1%), one that was selectively impaired with deficits in processing speed (32.6%), and one that was globally impaired across verbal learning, working memory, and executive skills (21.2%). The globally and selectively impaired subgroups were characterized by greater perceived stress and subjective cognitive complaints, poorer work and social adjustment, and reduced quality of life compared to patients who were cognitively intact.

LIMITATIONS

The study design was cross-sectional which limits inferences regarding the causality of the findings.

CONCLUSION

Globally and selectively impaired bipolar disorder patients displayed more functional disabilities than those who were cognitively intact. The present findings highlight a clinical need to systematically screen for cognitive dysfunction in remitted bipolar disorder and to target residual cognitive dysfunction in future treatment strategies.

Auditory Vigilance and Working Memory in Youth at Familial Risk for Schizophrenia or Affective Psychosis in the Harvard Adolescent Family High Risk Study

BACKGROUND

The degree of overlap between schizophrenia (SCZ) and affective psychosis (AFF) has been a recurring question since Kraepelin's subdivision of the major psychoses. Studying nonpsychotic relatives allows a comparison of disorder-associated phenotypes, without potential confounds that can obscure distinctive features of the disorder. Because attention and working memory have been proposed as potential endophenotypes for SCZ and AFF, we compared these cognitive features in individuals at familial high-risk (FHR) for the disorders.

METHODS

Young, unmedicated, first-degree relatives (ages, 13-25 years) at FHR-SCZ (n=41) and FHR-AFF (n=24) and community controls (CCs, n=54) were tested using attention and working memory versions of the Auditory Continuous Performance Test. To determine if schizotypal traits or current psychopathology accounted for cognitive deficits, we evaluated psychosis proneness using three Chapman Scales, Revised Physical Anhedonia, Perceptual Aberration, and Magical Ideation, and assessed psychopathology using the Hopkins Symptom Checklist -90 Revised.

RESULTS

Compared to controls, the FHR-AFF sample was significantly impaired in auditory vigilance, while the FHR-SCZ sample was significantly worse in working memory. Both FHR groups showed significantly higher levels of physical anhedonia and some psychopathological dimensions than controls. Adjusting for physical anhedonia, phobic anxiety, depression, psychoticism, and obsessive-compulsive symptoms eliminated the FHR-AFF vigilance effects but not the working memory deficits in FHR-SCZ.

CONCLUSIONS

The working memory deficit in FHR-SZ was the more robust of the cognitive impairments after accounting for psychopathological confounds and is supported as an endophenotype. Examination of larger samples of people at familial risk for different psychoses remains necessary to confirm these findings and to clarify the role of vigilance in FHR-AFF. (JINS, 2016, 22, 1026-1037).

Impact of psychotic symptoms on cognitive functioning in child and adolescent psychiatric inpatients with severe mood disorders

Despite established differences in cognitive functioning of adults with mood disorder-related psychosis and those with non-affective psychotic disorders, there is limited evidence of the impact of psychotic symptoms on the cognitive functioning of children and adolescents with mood disorders. This study investigates IQ, working memory, and processing speed scores in 80 child and adolescent inpatients discharged from an intermediate care state psychiatric hospital, using a retrospective chart review. Associations between diagnosis based on DSM-IV criteria (7 with Major Depression- MDD; 43 with Bipolar Disorders-BD, and 30 with Mood Disorders Not Otherwise Specified-NOS), presence of current psychotic features, and cognitive functioning (WISC-IV IQ, Coding, Symbol Search, and Digit Span) were investigated using Multivariate Analyses of Variance. No differences were found in cognitive functioning between patients with MDD and BD, or between those with severe Mood Disorders (MDD or BD) and those with NOS, when controlling for age, gender, and presence of psychotic features. However, patients with severe mood disorders and psychotic features showed lower IQs and greater working memory deficits than those without psychotic features or NOS. Results are discussed in terms of treatment planning for children and adolescents at risk for developing psychotic symptoms and severe mood disorders.

Cognitive enhancement treatments for bipolar disorder: A systematic review and methodological recommendations

Cognitive dysfunction is an emerging treatment target in bipolar disorder (BD). Several trials have assessed the efficacy of novel pharmacological and psychological treatments on cognition in BD but the findings are contradictory and unclear. A systematic search following the PRISMA guidelines was conducted on PubMed and PsychInfo. Eligible articles reported randomized, controlled or open-label trials investigating pharmacological or psychological treatments targeting cognitive dysfunction in BD. The quality of the identified randomized controlled trials (RCTs) was evaluated with the Cochrane Collaboration's Risk of Bias tool. We identified 19 eligible studies of which 13 were RCTs and six were open-label or non-randomized studies. The findings regarding efficacy on cognition were overall disappointing or preliminary, possibly due to several methodological challenges. For the RCTs, the risk of bias was high in nine cases, unclear in one case and low in three cases. Key reasons for the high risk of bias were lack of details on the randomization process, suboptimal handling of missing data and lack of a priori priority between cognition outcomes. Other challenges were the lack of consensus on whether and how to screen for cognitive impairment and on how to assess efficacy on cognition. In conclusion, methodological problems are likely to impede the success rates of cognition trials in BD. We recommend adherence to the CONSORT guidelines for RCTs, screening for cognitive impairment before inclusion of trial participants and selection of one primary cognition outcome. Future implementation of a 'neurocircuitry-based' biomarker model to evaluate neural target engagement is warranted.

Transdiagnostic neural markers of emotion-cognition interaction in psychotic disorders

Deficits in working memory (WM) and emotion processing are prominent impairments in psychotic disorders, and have been linked to reduced quality of life and real-world functioning. Translation of knowledge regarding the neural circuitry implementing these deficits into improved diagnosis and targeted treatments has been slow, possibly because of categorical definitions of disorders. Using the dimensional Research Domain Criteria (RDoC) framework, we investigated the clinical and practical utility of transdiagnostic behavioral and neural measures of emotion-related WM disruption across psychotic disorders. Behavioral and functional MRI data were recorded while 53 participants with psychotic disorders and 29 participants with no history of psychosis performed a modified n-back task with fear and neutral distractors. Hierarchical regression analyses showed that psychotic symptoms entered after diagnosis accounted for unique variance in fear versus neutral accuracy and activation in the ventrolateral, dorsolateral, and dorsomedial prefrontal cortex, but diagnostic group entered after psychotic symptoms did not. These results remained even after controlling for negative symptoms, disorganized symptoms, and dysphoria. Finally, worse accuracy and greater prefrontal activity were associated with poorer social functioning and unemployment across diagnostic groups. Present results support the transdiagnostic nature of behavioral and neuroimaging measures of emotion-related WM disruption as they relate to psychotic symptoms, irrespective of diagnosis. They also provide support for the practical utility of these markers in explaining real-world functioning. Overall, these results elucidate key aspects of the RDoC construct of WM maintenance by clarifying its transdiagnostic importance and clinical utility in psychotic disorders. (PsycINFO Database Record

Diagnosis and neurocognitive profiles in first-episode non-affective psychosis patients

This study explored whether there are distinguishable neurocognitive profiles in diagnostic subgroups of first-episode non-affective psychosis (FEP) patients. Four hundred and eighty-seven individuals with diagnoses of non-affective psychosis disorders were evaluated 6 months after first contact with psychiatric services. Individuals with schizophrenia (n = 257), schizophreniform (n = 141), brief psychotic disorder (n = 54), and psychosis not otherwise specified (n = 35) were compared on baseline neuropsychological variables using analyses of variance and covariance with potential clinical, premorbid, and sociodemographic confounders. The brief psychotic disorder subgroup was the least impaired on global cognitive function, in particular when compared to the schizophrenia subgroup, and specifically on executive function, processing speed, and motor dexterity domains. However, with the exception of the processing speed domain, profile differences could be explained by sex, age, psychotic and negative symptoms, years of education, and premorbid IQ. These results suggest processing speed as a diagnostic marker for brief psychotic disorder in FEP patients. Further, there are quantitative and qualitative differences across the schizophrenia spectrum disorders subgroups, indicating different profiles with varying degrees of deficit.

Maternal T. gondii, offspring bipolar disorder and neurocognition

Prenatal exposure to maternal Toxoplasma gondii (T. gondii) IgG antibody titer has been associated previously with an increased risk of offspring schizophrenia (SZ) and cognitive impairment. We examined maternal T. gondii, offspring bipolar disorder (BP) and childhood cognition using a population-based birth cohort. Maternal sera, drawn in the third trimester, were analyzed for T. gondii IgG antibody titer, and offspring cognition at ages 5 and 9-11 was measured with the Peabody Picture Vocabulary Test (PPVT) and the Raven Matrices (Raven). Raw scores were standardized and the ages combined. Potential cases with BP from the cohort were identified by database linkages. This protocol identified 85 cases who were matched 1:2 to controls. Maternal T. gondii IgG was not associated with the risk of BP in offspring. Neither moderate [HR=1.43 (CI: 0.49, 4.17)] nor high IgG titer [HR=1.6 [CI: 0.74, 3.48)] were associated with offspring BP. Associations were not observed between maternal T. gondii and BP with psychotic features or BP type 1. In addition, maternal T. gondii was not associated with childhood cognition. Our study suggests that T. gondii may be specific to SZ among major psychotic disorders, though further studies with larger sample sizes are required.

The Use of the Addiction Severity Index Psychiatric Composite Scores to Predict Psychiatric Inpatient Admissions

The high prevalence of co-occurring mental health and substance use disorders indicates a need for integrated behavioral health treatment that addresses both types of disorder simultaneously. One component of this integrated treatment is the use of an assessment process that can concurrently identify the presence of each class of disorder. The Addiction Severity Index (ASI) has been extensively used and researched in the field of substance use disorders for over 30 years. The ASI has seven sections, including a section on substance use disorders and a section on psychiatric symptoms, making it a potential candidate for a co-occurring screen during intake. The following study utilized a receiver operating characteristic curve analysis to determine an optimal cutoff score on the ASI psychiatric composite score to identify which individuals seeking substance use disorder treatment were admitted to the Milwaukee County Behavioral Health Division's psychiatric hospital in the year subsequent to their ASI administration. Of the 19,320 individuals who completed an initial ASI in our system, 343 had an inpatient admission. The receiver operating characteristic curve was statistically significant, with an area under the curve of 0.75. A cutoff of 0.27 had a sensitivity of 0.77 and a specificity of 0.61, such that over 60% (11,963/19,320) of the sample was excluded. These results suggest that the ASI psychiatric composite score may be a useful initial screen to identify those with potential mental health problems/needs in a behavioral health system attempting to integrate addiction and mental health services.

Positive schizotypy and negative schizotypy are associated with differential patterns of episodic memory impairment

Cognitive impairment is a hallmark of schizophrenia; however, studies have not comprehensively examined such impairments in non-clinically ascertained schizotypic young adults. The present study employed a series of measures to assess episodic memory in high positive schizotypy, high negative schizotypy, and comparison groups (each group n = 25). Consistent with diminished cognitive functioning seen in negative symptom schizophrenia, the negative schizotypy group exhibited deficits on free recall, recognition, and source memory tasks. The positive schizotypy group did not demonstrate deficits on the above mentioned tasks. However, in contrast to the other groups, the positive schizotypy group showed an unexpected set-size effect on the cued-recall task. Set-size effect, which refers to the finding that words that have smaller networks of associates tend to have a memory advantage, is usually found in associative-cuing, but not cued-recall, tasks. The finding for the positive schizotypy group is consistent with heightened spreading activation and reduced executive control suggested to underlie psychotic symptoms. The findings support a multidimensional model of schizotypy and schizophrenia, and suggest that positive and negative schizotypy involve differential patterns of cognitive impairment.

Re-conceptualizing ASD Within a Dimensional Framework: Positive, Negative, and Cognitive Feature Clusters

Introduction of the National Institute of Mental Health's Research Domain Criteria and revision of diagnostic classification for Autism Spectrum Disorder in the latest diagnostic manual call for a new way of conceptualizing heterogeneous ASD features. We propose a novel conceptualization of ASD, borrowing from the schizophrenia literature in clustering ASD features along positive, negative, and cognitive dimensions. We argue that this dimensional conceptualization can offer improved ability to classify, diagnose, and treat, to apply and predict response to treatment, and to explore underlying neural and genetic alterations that may contribute to particular feature clusters. We suggest the proposed conceptualization can advance the field in a manner that may prove clinically and biologically useful for understanding and addressing heterogeneity within ASD.

Liability indicators aggregate many years before transition to illness in offspring descending from kindreds affected by schizophrenia or bipolar disorder

OBJECTIVES

Offspring born to patients with affective and non-affective psychoses display indicators of brain dysfunctions that affected parents carry. Such indicators may help understand the risk trajectory.

METHODS

We followed up the clinical/developmental trajectories of 84 young offspring born to affected parents descending from the Quebec kindreds affected by schizophrenia or bipolar disorder. We longitudinally characterized childhood trajectories using 5 established risk indicators: cognitive impairments, psychotic-like experiences, non-psychotic DSM diagnosis and episodes of poor functioning, trauma and drug use.

RESULTS

Overall, offspring individually presented a high rate of risk indicators with 39% having 3 or more indicators. Thirty-three offspring progressed to an axis 1 DSM-IV disorder, 15 of whom transitioned to a major affective or non-affective disorder. The relative risks for each risk indicator were low in these vulnerable offspring (RR = 1.92 to 2.99). Remarkably, transitioners accumulated more risk indicators in childhood-adolescence than non-transitioners (Wilcoxon rank test; Z = 2.64, p = 0.008). Heterogeneity in the risk trajectories was observed. Outcome was not specific to parent's diagnosis.

CONCLUSION

Young offspring descending from kindreds affected by major psychoses would accumulate risk indicators many years before transition. A clustering of risk factors has also been observed in children at risk of metabolic-cardiovascular disorders and influences practice guidelines in this field. Our findings may be significant for the primary care surveillance of millions of children born to affected parents in the G7 nations. Future longitudinal risk research of children at genetic risk should explore concurrently several intrinsic and environmental risk modalities to increase predictivity.

Executive dysfunction and cognitive subgroups in a large sample of euthymic patients with bipolar disorder

Bipolar disorder (BP), at the group level, is associated with significant but modest cognitive deficits, including executive dysfunction. Among executive functions, response inhibition deficits have been suggested to be particularly relevant to BP. However, BP is associated with significant heterogeneity in neurocognitive performance and level of functioning. Very few studies have investigated neurocognitive subgroups in BP with data-driven methods rather than arbitrarily defined criteria. Other than having relatively small sample sizes, previous studies have not taken into consideration the neurocognitive variability in healthy subjects. Five-hundred-fifty-six euthymic patients with BP and 416 healthy controls were assessed using a battery of cognitive tests and clinical measures. Neurocognitive subgroups were investigated using latent class analysis, based on executive functions. Four neurocognitive subgroups, including a good performance cluster, two moderately low-performance groups, which differ in response inhibition and reasoning abilities, and a severe impairment cluster were found. In comparison to healthy controls, BP patients were overrepresented in severe impairment cluster (27% vs 5.3%) and underrepresented in good performance cluster. BP patients with lower educational attainment and older age were significantly more likely to be members of cognitively impaired subgroups. Antipsychotic use was less common in good performance cluster. These results suggest that there is a considerable overlap of cognitive functions between BP and healthy controls. Neurocognitive differences between BP and healthy controls are driven by a subgroup of patients who have severe and global, rather than selective, cognitive deficits.

Areas of controversy in neuroprogression in bipolar disorder

OBJECTIVE

We aimed to review clinical features and biological underpinnings related to neuroprogression in bipolar disorder (BD). Also, we discussed areas of controversy and future research in the field.

METHOD

We systematically reviewed the extant literature pertaining to neuroprogression and BD by searching PubMed and EMBASE for articles published up to March 2016.

RESULTS

A total of 114 studies were included. Neuroimaging and clinical evidence from cross-sectional and longitudinal studies show that a subset of patients with BD presents a neuroprogressive course with brain changes and unfavorable outcomes. Risk factors associated with these unfavorable outcomes are number of mood episodes, early trauma, and psychiatric and clinical comorbidity.

CONCLUSION

Illness trajectories are largely variable, and illness progression is not a general rule in BD. The number of manic episodes seems to be the clinical marker more robustly associated with neuroprogression in BD. However, the majority of the evidence came from cross-sectional studies that are prone to bias. Longitudinal studies may help to identify signatures of neuroprogression and integrate findings from the field of neuroimaging, neurocognition, and biomarkers.

Psychotic disorders in DSM-5 and ICD-11

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) was published by the American Psychiatric Association (APA) in 2013, and the Work Group on the Classification of Psychotic disorders (WGPD), installed by the World Health Organization (WHO), is expected to publish the new chapter about schizophrenia and other primary psychotic disorders in 2017. We reviewed the available literature to summarize the major changes, innovations, and developments of both manuals. If available and possible, we outline the theoretical background behind these changes. Due to the fact that the development of ICD-11 has not yet been completed, the details about ICD-11 are still proposals under ongoing revision. In this ongoing process, they may be revised and therefore have to be seen as proposals. DSM-5 has eliminated schizophrenia subtypes and replaced them with a dimensional approach based on symptom assessments. ICD-11 will most likely go in a similar direction, as both manuals are planned to be more harmonized, although some differences will remain in details and the conceptual orientation. Next to these modifications, ICD-11 will provide a transsectional diagnostic criterion for schizoaffective disorders and a reorganization of acute and transient psychotic and delusional disorders. In this manuscript, we will compare the 2 classification systems.

A confirmatory factor analysis of the MATRICS consensus cognitive battery in severe mental illness

BACKGROUND

A recent factor analysis of Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB) data in a sample of schizophrenia-spectrum patients described a three factor model representing processing speed, attention/working memory, and learning; the social cognition measure was excluded from the analysis. The current analyses sought to replicate a three factor structure of the MCCB in a larger, more diagnostically diverse sample of participants.

METHODS

Confirmatory factor analyses were performed to evaluate the factor structure of the MCCB in 300 outpatients with severe mental illness (54.3% schizophrenia-spectrum diagnoses) who were participants in three studies of cognitive remediation. Exploratory analyses were conducted to evaluate the concurrent prediction of symptoms from MCCB factor scores.

RESULTS

The three factor structure of the MCCB demonstrated stronger model fit (χ(2)=14.53, p=0.75, SRMR=0.02, RMSEA=0.0, CFI=1.00, NNFI=1.01) than the unifactoral structure. Poorer cognitive performance across all three MCCB factors was significantly correlated with more severe overall and disorganization symptoms from the PANSS and BPRS, and less severe affective symptoms (e.g., depression, anxiety) in the overall sample.

CONCLUSIONS

A three factor structure of the MCCB-composed of processing speed, attention/working memory, and learning-was replicated in a heterogeneous sample of persons with severe mental illness. Cognitive performance on the MCCB factors is associated with clinical symptoms.

Validation of the cognitively normal range and below normal range subtypes in chronically hospitalized patients with schizophrenia

Background

Many studies have found a substantial minority of patients whose performance puts them within the normal range of neuropsychological functioning. Recently, a study has seen the delineation of two neurocognitive subtypes of schizophrenia –‘cognitively normal range’ (CNR) and ‘below normal range’ (BNR) – based on neurocognitive performance across multiple domains.

Methods

The participants were from two studies that collected neurocognitive, psychopathology and social function data between 2008 and 2015. In total the complete data from one hundred and thirty one patients of Han Chinese ethnicity with schizophrenia were collected on 21 neurocognitive indexes (assessing the domains of processing speed, attention, working memory, verbal memory, visual memory, reasoning and problem solving and IQ). Fifty-five patients of the one hundred and thirty one participants received additional ratings on their psychopathology and social functions. An exploratory graphic analysis was conducted on the neurocognitive measures for the entire sample. Difference analyses were also performed according to the aims of the study using the Independent t test, Chi-square test, and Cohen's d effect size.

Results

Analyses revealed the existence of two patients subtypes. The post hoc tests showed that there were significant differences on all of their neurocognitive measures and on most of the psychopathology and social functions between the two subtypes. These two subtypes could be referred to as the CNR subtype and the BNR subtype respectively.

Conclusions

There are neurocognitive subtypes of schizophrenia with differential illness characteristics comparable with the CNR and the BNR in patients of Han Chinese ethnicity with schizophrenia.

Disconnection Between Amygdala and Medial Prefrontal Cortex in Psychotic Disorders

Distracting emotional information impairs attention more in schizophrenia (SCZ) than in never-psychotic individuals. However, it is unclear whether this impairment and its neural circuitry is indicative generally of psychosis, or specifically of SCZ, and whether it is even more specific to certain SCZ symptoms (eg, deficit syndrome). It is also unclear if this abnormality contributes to impaired behavioral performance and real-world functioning. Functional imaging data were recorded while individuals with SCZ, bipolar disorder with psychosis (BDP) and no history of psychotic disorders (CON) attended to identity of faces while ignoring their emotional expressions. We examined group differences in functional connectivity between amygdala, involved in emotional evaluation, and sub-regions of medial prefrontal cortex (MPFC), involved in emotion regulation and cognitive control. Additionally, we examined correlation of this connectivity with deficit syndrome and real-world functioning. Behaviorally, SCZ showed the worst accuracy when matching the identity of emotional vs neutral faces. Neurally, SCZ showed lower amygdala-MPFC connectivity than BDP and CON. BPD did not differ from CON, neurally or behaviorally. In patients, reduced amygdala-MPFC connectivity during emotional distractors was related to worse emotional vs neutral accuracy, greater deficit syndrome severity, and unemployment. Thus, reduced amygdala-MPFC functional connectivity during emotional distractors reflects a deficit that is specific to SCZ. This reduction in connectivity is associated with worse clinical and real-world functioning. Overall, these findings provide support for the specificity and clinical utility of amygdala-MPFC functional connectivity as a potential neural marker of SCZ.

Predictors of neurocognitive impairment at 2years after a first-episode major depressive disorder

BACKGROUND

Neurocognitive impairment is a contributor to major depressive disorder (MDD). However, MDD patients show great variability in the level and course of deficits. The present longitudinal study was to identify predictors of neurocognitive impairment in first-episode MDD patients.

METHODS

Neurocognitive performance was analyzed in a cohort of 100 patients at 2years after a first-episode MDD. Subgroups, deficit type vs. non-deficit type, were compared on baseline clinical, neuropsychological, premorbid and sociodemographic characteristics. The analysis was performed using the multivariate logistic regression to obtain a model for neurocognitive impairment determination. The predicted probabilities of multivariate logistic regression were analyzed using receiver operating characteristic (ROC) curve.

RESULTS

Fifty-two percent of MDD participants presented general neurocognitive impairment. The regression analyses demonstrated that clinical and sociodemographic characteristics were not predictive variables. A model composed of processing speed, executive function, and attention, dexterity correctly classified 85.8% of the MDD patients with deficit type. ROC curve indicated that the changes of these three cognitions could identify MDD with deficit type from MDD with non-deficit type. In addition, ROC curve also indicated that processing speed and executive function could identify MDD from CN subjects. Finally, processing speed performance was negatively correlated with Hamilton Depression Scale scores in both MDD with deficit and non-deficit type.

CONCLUSION

The present study provides novel insights on frequency and neurocognitive profile of subtypes of patients showing impairment. Our results suggest that processing speed impairment is a trait dimension of the disorder related to specific cognitive dysfunctions and the severity of depression.

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.

Biological aspects and candidate biomarkers for psychotic bipolar disorder: A systematic review

AIM

We carried out a systematic review of the available literature about potential biomarkers of psychotic bipolar disorder (BD-P), a specific subset presenting worse outcome and greater risk of relapse than non-psychotic bipolar disorder (BD-NP).

METHODS

We searched the main psychiatric databases (PubMed, ISI Web of Knowledge, PsychInfo). Only original articles with the main topic of BD-P compared to schizophrenia/BD-NP/healthy controls (HC) written in English from 1994 to 2015 were included.

RESULTS

BD-P patients presented higher kynurenic acid levels in the cerebrospinal fluid, elevated anti- S accharomyces cerevisiae antibodies levels, and lower serum levels of dehydroepiandrosterone sulfate and progesterone than BD-NP/HC. Event-related potentials abnormalities have been identified in BD-P with respect to BD-NP. BD-P patients also presented bigger ventricles but similar hippocampal volumes compared to BD-NP/HC. Although the results are contrasting, some cognitive deficits seemed to be related to the psychotic dimension of bipolar affective disorder, such as impairment in verbal/logical memory, working memory, verbal and semantic fluency and executive functioning. Finally, polymorphisms of genes, such as NRG1, 5HTTLPR (s), COMT, DAOA and some chromosome regions (16p12 and 13q), were positively associated with BD-P.

CONCLUSION

Data about the identification of specific biomarkers for BD-P are promising, but most of them have not yet been replicated. They could lead the clinicians to an early diagnosis and proper treatment, thus ameliorating outcome of BD-P and reducing the biological changes associated with a long duration of illness. Further studies with bigger samples are needed to detect more specific biological markers of the psychotic dimension of bipolar affective disorder.

Cognitive variability in bipolar II disorder: who is cognitively impaired and who is preserved

OBJECTIVES

Although it is well established that euthymic patients with bipolar disorder can have cognitive impairment, substantial heterogeneity exists and little is known about the extent and severity of impairment within the bipolar II disorder subtype. Therefore, the main aim of this study was to analyze cognitive variability in a sample of patients with bipolar II disorder.

METHODS

The neuropsychological performance of 116 subjects, including 64 euthymic patients with bipolar II disorder and 52 healthy control subjects, was examined and compared by means of a comprehensive neurocognitive battery. Neurocognitive data were analyzed using a cluster analysis to examine whether there were specific groups based on neurocognitive patterns. Subsequently, subjects from each cluster were compared on demographic, clinical, and functional variables.

RESULTS

A three-cluster solution was identified with an intact neurocognitive group (n = 29, 48.3%), an intermediate or selectively impaired group (n = 24, 40.0%), and a globally impaired group (n = 7, 11.6%). Among the three clusters, statistically significant differences were observed in premorbid intelligence quotient (p = 0.002), global functional outcome (p = 0.021), and leisure activities (p = 0.001), with patients in the globally impaired cluster showing the lowest attainments. No differences in other clinical characteristics were found among the groups.

CONCLUSIONS

These results confirm that neurocognitive variability is also present among patients with bipolar II disorder. Approximately one-half of the patients with bipolar II disorder were cognitively impaired, and among them 12% were severely and globally impaired. The identification of different cognitive profiles may help to develop cognitive remediation programs specifically tailored for each cognitive profile.

High educational performance is a distinctive feature of bipolar disorder: a study on cognition in bipolar disorder, schizophrenia patients, relatives and controls

BACKGROUND

Schizophrenia is associated with lower intelligence and poor educational performance relative to the general population. This is, to a lesser degree, also found in first-degree relatives of schizophrenia patients. It is unclear whether bipolar disorder I (BD-I) patients and their relatives have similar lower intellectual and educational performance as that observed in schizophrenia.

METHOD

This cross-sectional study investigated intelligence and educational performance in two outpatient samples [494 BD-I patients, 952 schizophrenia spectrum (SCZ) patients], 2231 relatives of BD-I and SCZ patients, 1104 healthy controls and 100 control siblings. Mixed-effects and regression models were used to compare groups on intelligence and educational performance.

RESULTS

BD-I patients were more likely to have completed the highest level of education (odds ratio 1.88, 95% confidence interval 1.66-2.70) despite having a lower IQ compared to controls (β = -9.09, S.E. = 1.27, p < 0.001). In contrast, SCZ patients showed both a lower IQ (β = -15.31, S.E. = 0.86, p < 0.001) and lower educational levels compared to controls. Siblings of both patient groups had significantly lower IQ than control siblings, but did not differ on educational performance. IQ scores did not differ between BD-I parents and SCZ parents, but BD-I parents had completed higher educational levels.

CONCLUSIONS

Although BD-I patients had a lower IQ than controls, they were more likely to have completed the highest level of education. This contrasts with SCZ patients, who showed both intellectual and educational deficits compared to healthy controls. Since relatives of BD-I patients did not demonstrate superior educational performance, our data suggest that high educational performance may be a distinctive feature of bipolar disorder patients.

Characteristics and heterogeneity of schizoaffective disorder compared with unipolar depression and schizophrenia - a systematic literature review and meta-analysis

BACKGROUND

Comparisons of illness characteristics between patients with schizoaffective disorder (SAD) patients and unipolar depression (UD) are rare, even though UD is one of the most important differential diagnoses of SAD. Also, the variability of illness characteristics (heterogeneity) has not been compared. We compared illness characteristics and their heterogeneity among SAD, UD, and - as another important differential diagnosis - schizophrenia (S).

METHODS

In order to reduce sampling bias we systematically searched for studies simultaneously comparing samples of patients with SAD, UD, and S. Using random effects and Mantel-Haenszel models we estimated and compared demographic, illness course and psychopathology parameters, using pooled standard deviations as a measurement of heterogeneity.

RESULTS

Out of 155 articles found by an earlier meta-analysis, 765 screened in Medline, 2738 screened in EMBASE, and 855 screened in PsycINFO we selected 24 studies, covering 3714 patients diagnosed according to RDC, DSM-III, DSM-IIIR, DSM-IV, or ICD-10. In almost all key characteristics, samples with schizoaffective disorders fell between unipolar depression and schizophrenia, with a tendency towards schizophrenia. On average, UD patients were significantly older at illness onset (33.0 years, SAD: 25.2, S: 23.4), more often women (59% vs. 57% vs. 39%) and more often married (53% vs. 39% vs. 27%). Their psychopathology was also less severe, as measured by BPRS, GAS, and HAMD. In demographic and clinical variables heterogeneity was roughly 5% larger in UD than in SAD, and samples of patients with schizophrenia had the lowest pooled heterogeneity. A similar picture emerged in a sensitivity analysis with coefficient of variation as the measurement of heterogeneity.

LIMITATIONS

Relative to bipolar disorder there are fewer studies including unipolar patients. No studies based on DSM-5 could be included.

CONCLUSIONS

Regarding unipolar affective disorder this study confirms what we have shown for bipolar disorders in earlier studies: schizoaffective disorder falls between schizophrenia and affective disorders, and there are relevant quantitative differences in key illness characteristics, which supports the validity of the schizoaffective disorder concept. Contrary to our expectations heterogeneity is not larger in SAD than in UD and not substantially higher than in S. Lower reliability of the diagnosis of SAD therefore cannot be ascribed to higher variability of illness characteristics in SAD.

Cognitive Deficits as a Mediator of Poor Occupational Function in Remitted Major Depressive Disorder Patients

Cognitive deficits in major depressive disorder (MDD) patients have been described in numerous studies. However, few reports have aimed to describe cognitive deficits in the remitted state of MDD and the mediational effect of cognitive deficits on occupational outcome. The aim of the current review is to synthesize the literature on the mediating and moderating effects of specific domains of cognition on occupational impairment among people with remitted MDD. In addition, predictors of cognitive deficits found to be vocationally important will be examined. Upon examination of the extant literature, attention, executive function and verbal memory are areas of consistent impairment in remitted MDD patients. Cognitive domains shown to have considerable impact on vocational functioning include deficits in memory, attention, learning and executive function. Factors that adversely affect cognitive function related to occupational accommodation include higher age, late age at onset, residual depressive symptoms, history of melancholic/psychotic depression, and physical/psychiatric comorbidity, whereas higher levels of education showed a protective effect against cognitive deficit. Cognitive deficits are a principal mediator of occupational impairment in remitted MDD patients. Therapeutic interventions specifically targeting cognitive deficits in MDD are needed, even in the remitted state, to improve functional recovery, especially in patients who have a higher risk of cognitive deficit.

Unitary construct of generalized cognitive ability underlying BACS performance across psychotic disorders and in their first-degree relatives

Despite robust evidence of neurocognitive dysfunction in psychotic patients, the degree of similarity in cognitive architecture across psychotic disorders and among their respective first-degree relatives is not well delineated. The present study examined the latent factor structure of the Brief Assessment of Cognition in Schizophrenia (BACS) neuropsychological battery. Analyses were conducted on 783 psychosis spectrum probands (schizophrenia, schizoaffective, psychotic bipolar), 887 of their first-degree relatives, and 396 non-psychiatric controls from the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP) consortium. Exploratory factor analysis of BACS subtest scores indicated a single-factor solution that was similar across all groups and provided the best overall data fit in confirmatory analyses. Correlations between the standard BACS composite score and the sum of subscale scores weighted by their loadings on this unitary factor were very high in all groups (r≥.99). Thus, the BACS assesses a similar unitary cognitive construct in probands with different psychotic disorders, in their first-degree relatives, and in healthy controls, and this factor is well measured by the test's standard composite score.

The effect of daily small text message reminders for medicine compliance amongst young people connected with the outpatient department for child and adolescent psychiatry. A controlled and randomized investigation

BACKGROUND

Many patients with psychiatric illnesses have difficulty maintaining medication over time. Many take their medicine irregularly and studies show that it is the most vulnerable patients who have the greatest problems adhering to treatment. Often only 50% are still under medical treatment after 6 months.

AIM

In this study we investigated whether text message reminders could improve medicine compliance amongst vulnerable young people with psychiatric disorders who were being treated in the outpatient department for child and adolescent psychiatry and who either are under or were to commence medicinal treatment.

METHODS

This study was conducted as a randomized controlled trial including all non-acute referrals to an outpatient department for adolescent psychiatry within a group aged 15-20 years starting medical treatment. The patients were followed until the end of their treatment, for a minimum of 3 months. To enhance medicine compliance, text messages were sent daily to one group. No message was sent to the other group.

RESULTS

Compliance was not associated with text message intervention in any of the drug interventions. The effect size was calculated to 0.3013, which is low and therefore indicates a weak association between text message and compliance. The power in this study was calculated to 0.3539, which is also low and therefore the likelihood of finding significant association is low.

CONCLUSION

This study does not show increased medicine compliance from the text message intervention group. The conclusion of this study is that it is essential that significant resources are spent preparing and testing a text message strategy.

Effects of functional remediation on neurocognitively impaired bipolar patients: enhancement of verbal memory

BACKGROUND

Functional remediation is a novel intervention with demonstrated efficacy at improving functional outcome in euthymic bipolar patients. However, in a previous trial no significant changes in neurocognitive measures were detected. The objective of the present analysis was to test the efficacy of this therapy in the enhancement of neuropsychological functions in a subgroup of neurocognitively impaired bipolar patients.

METHOD

A total of 188 out of 239 DSM-IV euthymic bipolar patients performing below two standard deviations from the mean of normative data in any neurocognitive test were included in this subanalysis. Repeated-measures analyses of variance were conducted to assess the impact of the treatment arms [functional remediation, psychoeducation, or treatment as usual (TAU)] on participants' neurocognitive and functional outcomes in the subgroup of neurocognitively impaired patients.

RESULTS

Patients receiving functional remediation (n = 56) showed an improvement on delayed free recall when compared with the TAU (n = 63) and psychoeducation (n = 69) groups as shown by the group × time interaction at 6-month follow-up [F 2,158 = 3.37, degrees of freedom (df) = 2, p = 0.037]. However, Tukey post-hoc analyses revealed that functional remediation was only superior when compared with TAU (p = 0.04), but not with psychoeducation (p = 0.10). Finally, the patients in the functional remediation group also benefited from the treatment in terms of functional outcome (F 2,158 = 4.26, df = 2, p = 0.016).

CONCLUSIONS

Functional remediation is effective at improving verbal memory and psychosocial functioning in a sample of neurocognitively impaired bipolar patients at 6-month follow-up. Neurocognitive enhancement may be one of the active ingredients of this novel intervention, and, specifically, verbal memory appears to be the most sensitive function that improves with functional remediation.

Brain Structure in Neuropsychologically Defined Subgroups of Schizophrenia and Psychotic Bipolar Disorder

BACKGROUND

Neuropsychological impairment is heterogeneous in psychosis. The association of intracranial volume (ICV) and total brain volume (TBV) with cognition suggests brain structure abnormalities in psychosis will covary with the severity of cognitive impairment. We tested the following hypotheses: (1) brain structure abnormalities will be more extensive in neuropsychologically impaired psychosis patients; (2) psychosis patients with premorbid cognitive limitations will show evidence of hypoplasia (ie, smaller ICV); and (3) psychosis patients with evidence of cognitive decline will demonstrate atrophy (ie, smaller TBV, but normal ICV).

METHODS

One hundred thirty-one individuals with psychosis and 97 healthy subjects underwent structural magnetic resonance imaging and neuropsychological testing. Patients were divided into neuropsychologically normal and impaired groups. Impaired patients were further subdivided into deteriorated and compromised groups if estimated premorbid intellect was average or below average, respectively. ICV and TBV were compared across groups. Localized brain volumes were qualitatively examined using voxel-based morphometry.

RESULTS

Compared to healthy subjects, neuropsychologically impaired patients exhibited smaller TBV, reduced grey matter volume in frontal, temporal, and subcortical brain regions, and widespread white matter volume loss. Neuropsychologically compromised patients had smaller ICV relative to healthy subjects, and neuropsychologically normal and deteriorated patient groups, but relatively normal TBV. Deteriorated patients exhibited smaller TBV compared to healthy subjects, but relatively normal ICV. Unexpectedly, TBV, adjusted for ICV, was reduced in neuropsychologically normal patients.

CONCLUSIONS

Patients with long-standing cognitive limitations exhibit evidence of early cerebral hypoplasia, whereas neuropsychologically normal and deteriorated patients show evidence of brain tissue loss consistent with progression or later cerebral dysmaturation.

Exploring cognitive heterogeneity in first-episode psychosis: What cluster analysis can reveal

Variable outcomes in first-episode psychosis (FEP) are partly attributable to heterogeneity in cognitive functioning. To aid identification of those likely to have poorer or better outcomes, we examined whether purported cognitive profiles identified through use of cluster analysis in chronic schizophrenia were evident in FEP. We also aimed to assess whether there was a relationship between cognitive profile and factors independent of the solution, providing external validation that the cognitive profiles represented distinct subgroups. Ward's method hierarchical cluster analysis, verified by a k-means cluster solution, was performed using data obtained from a cognitive test battery administered to 128 participants aged 15-25 years. Four cognitive profiles were identified. A continuity element was evident; participants in cluster four were more cognitively impaired compared to participants in cluster three, who appeared more cognitively intact. Clusters one and two were distinguishable across measures of attention and working memory and visual recognition memory, most likely reflecting sample specific patterns of deficit. Participants in cluster four had significantly lower premorbid and current IQ and higher negative symptoms compared to participants in cluster three. The distinct levels and patterns of cognition found in chronic schizophrenia cohorts are also evident across diagnostic categories in FEP.

Longitudinal relations between symptoms, neurocognition, and self-concept in schizophrenia

Objective: Cognitive models suggest that the self-concept of persons with psychosis can be fundamentally affected. Self-concepts were found to be related to different symptom domains when measured concurrently. Longitudinal investigations to disentangle the possible causal associations are rare.

Method: We examined a sample of 160 people with a diagnosis of schizophrenia who took part in a psychotherapy study. All participants had the DSM-IV diagnosis of a schizophrenia and pronounced negative symptoms. Neurocognition, symptoms, and self-concepts were assessed at two time points 12 months apart. Structural equation modeling was used to test whether symptoms influence self-concepts (scar-model) or self-concepts affect symptoms (vulnerability model).

Results: Negative symptoms correlated concurrently with self-concepts. Neurocognitive deficits are associated with more negative self-concepts 12 months later. Interpersonal self-concepts were found to be relevant for paranoia.

Conclusion: The findings implicate that if deficits in neurocognition are present, fostering a positive self-concept should be an issue in therapy. Negative interpersonal self-concept indicates an increased risk for paranoid delusions in the course of 1 year. New aspects for cognitive models in schizophrenia and clinical implications are discussed.

Regressing to Prior Response Preference After Set Switching Implicates Striatal Dysfunction Across Psychotic Disorders: Findings From the B-SNIP Study

Difficulty switching behavioral response sets is established in psychotic disorders. In rodent models, prefrontal lesions cause difficulty initially switching to new response sets (perseverative errors) while striatal lesions cause difficulty suppressing responses to previous choice preferences (regressive errors). Studies of psychotic disorders have not previously assessed these 2 error types. Bipolar and Schizophrenia Network on Intermediate Phenotypes (B-SNIP) participants included probands with schizophrenia (N = 212), psychotic bipolar (N = 192), and schizoaffective disorder (N = 131), their first-degree relatives (N = 267,226,165 respectively), and healthy controls (N = 258). Participants completed the Penn Conditional Exclusion Test (PCET) to assess cognitive set switching and the Brief Assessment of Cognition in Schizophrenia (BACS) to assess generalized neuropsychological dysfunction. All proband groups displayed elevated rates of perseverative and regressive errors compared to controls. After correcting for generalized cognitive deficits to identify specific deficits in set shifting and maintenance, there were no significant group differences for perseverative errors, while the increased rate of regressive errors remained significant. Level of regressive errors was similar across proband groups with minimal correlations with antipsychotic medication dose, clinical ratings, and demographic characteristics. Relatives of schizophrenia patients showed increased rates of regressive errors, but familiality of this trait was significant only in bipolar pedigrees. Regressive errors were partially independent of generalized cognitive deficits, suggesting a potentially informative and specific cognitive deficit across psychotic disorders. Preclinical data indicate that this deficit could be related to altered function in a neural system that may include the dorsal striatum or other elements of frontostriatal systems.

Toward the identification of neurocognitive subtypes in euthymic patients with bipolar disorder

BACKGROUND

Cross-sectional and meta-analytic studies showed that patients with bipolar disorder (BD) had neurocognitive impairments even during periods of euthymia. The aim of this study was to estimate the prevalence of BD patients with and without clinically significant cognitive impairments, as well as to analyze clinical and functional variables in these subgroups.

METHODS

Hundred patients with BD and 40 healthy controls were assessed with an extensive neurocognitive assessment. Soft (some cognitive domain with a performance below 1.5 SD of the mean) and hard (at least two domains with values below 2 SD of the mean) criteria were utilized to define clinically significant cognitive impairments.

RESULTS

Using both soft and hard criteria, the prevalence of clinically significant cognitive impairments was higher in people with BD than in healthy controls. 70% of patients only showed failures of small effect (d=0.21-0.35) in 2 measures of executive functions. Moreover, 30% of patients were indistinguishable from healthy subjects in terms of both neurocognitive and psychosocial functioning. On the contrary, 30% of the sample showed more severe cognitive deficits than those usually reported in literature and had the worst psychosocial functioning.

CONCLUSIONS

The fact that cognitive impairments are very heterogeneous among euthymic patients with BD could contribute to understanding differences in functional outcome. Theoretical and practical implications of these findings are discussed.

Premorbid adjustment and clinical correlates of cognitive impairment in first-episode psychosis. The PEPsCog Study

BACKGROUND

The extent to which socio-demographic, clinical, and premorbid adjustment variables contribute to cognitive deficits in first-episode schizophrenia spectrum disorders remains to be ascertained.

AIMS

To examine the pattern and magnitude of cognitive impairment in first-episode psychosis patients, the profile of impairment across psychosis subtypes and the associations with premorbid adjustment.

METHODS

226 first-episode psychosis patients and 225 healthy controls were assessed in the PEPsCog study, as part of the PEPs study.

RESULTS

Patients showed slight to moderate cognitive impairment, verbal memory being the domain most impaired compared to controls. Broad affective spectrum patients had better premorbid IQ and outperformed the schizophrenia and other psychosis groups in executive function, and had better global cognitive function than the schizophrenia group. Adolescent premorbid adjustment together with age, gender, parental socio-economic status, and mean daily antipsychotic doses were the factors that best explained patients' cognitive performance. General and adolescent premorbid adjustment, age and parental socio-economic status were the best predictors of cognitive performance in controls.

CONCLUSIONS

Poorer premorbid adjustment together with socio-demographic factors and higher daily antipsychotic doses were related to a generalized cognitive impairment and to a lower premorbid intellectual reserve, suggesting that neurodevelopmental impairment was present before illness onset.

Comparison of cognitive deficits among drug-naive patients with schizophrenia and major depressive disorder

BACKGROUND

Cognitive deficits have been well-established among patients with severe mental illness. The aim of this study was to clarify the patterns of cognitive deficits in drug-naive patients with schizophrenia and non-psychotic major depressive disorder (MDD) as compared with controls.

METHODS

Thirty drug-naïve participants with schizophrenia, 30 counterparts with non-psychotic MDD, and 30 age-, sex-, and education years-matched healthy controls were recruited. Neuropsychological tests, including the Wisconsin Card Test (WCST), the Continuous Performance Test (CPT) and the Finger Tapping Test (FTT), were administered.

RESULTS

Patients with schizophrenia performed more poorly than the patients with MDD and the normal controls in the WCST. The patients with schizophrenia and the patients with MDD both performed more poorly than the normal controls in the CPT. The patients with MDD also performed more poorly than the normal controls in the FTT.

LIMITATIONS

The age of onset of MDD in this study was younger than in previous reports. The cross-sectional design, small sample sizes, and limited numbers of neuropsychological domains in this study are all obstacles to making a clear causal conclusion.

CONCLUSIONS

These results revealed a distinct pattern of neurocognitive dysfunction among drug-naive patients with schizophrenia and MDD, which may imply different underlying neurobiological mechanisms in schizophrenia and MDD.

Predictors of schizophrenia spectrum disorders in early-onset first episodes of psychosis: a support vector machine model

Identifying early-onset schizophrenia spectrum disorders (SSD) at a very early stage remains challenging. To assess the diagnostic predictive value of multiple types of data at the emergence of early-onset first-episode psychosis (FEP), various support vector machine (SVM) classifiers were developed. The data were from a 2-year, prospective, longitudinal study of 81 patients (age 9-17 years) with early-onset FEP and a stable diagnosis during follow-up and 42 age- and sex-matched healthy controls (HC). The input was different combinations of baseline clinical, neuropsychological, magnetic resonance imaging brain volumetric and biochemical data, and the output was the diagnosis at follow-up (SSD vs. non-SSD, SSD vs. HC, and non-SSD vs. HC). Enhanced recursive feature elimination was performed for the SSD vs. non-SSD classifier to select and rank the input variables with the highest predictive value for a diagnostic outcome of SSD. After validation with a test set and considering all baseline variables together, the SSD vs. non-SSD, SSD vs. HC and non-SSD vs. HC classifiers achieved an accuracy of 0.81, 0.99 and 0.99, respectively. Regarding the SSD vs. non-SSD classifier, a combination of baseline clinical variables (severity of negative, disorganized symptoms and hallucinations or poor insight) and neuropsychological variables (impaired attention, motor coordination, and global cognition) showed the highest predictive value for a diagnostic outcome of SSD. Neuroimaging and biochemical variables at baseline did not add to the predictive value. Thus, comprehensive clinical/cognitive assessment remains the most reliable approach for differential diagnosis during early-onset FEP. SVMs may constitute promising multivariate tools in the search for predictors of diagnostic outcome in FEP.

Neurocognitive functioning in the premorbid stage and in the first episode of bipolar disorder: a systematic review

It is well known that patients with bipolar disorder (BD) have cognitive impairments even during periods of euthymia. However, to date it remains unclear the moment when these deficits onset. Therefore, the aim of this study was to review the evidence focusing on the cognitive status of patients with BD in their premorbid stage and in their first episode. An extensive search was conducted through the online databases Pubmed/PsychInfo, covering the period between 1980 and 2014. A total of 23 studies were selected for the review (nine studies explored premorbid stage of people who lately develop BD and 14 examined first-episodes in bipolar patients). There is evidence that general intelligence is not impaired in the premorbid stage. Impairments in verbal memory, attention, and executive functions tend to be present during and after the first episode. Preliminary evidence suggests that these deficits in specific cognitive domains might precede the onset of illness.

Oxytocin and social cognition in affective and psychotic disorders

Impairments in social cognition are now recognized as core illness features in psychotic and affective disorders. Despite the significant disability caused by social cognitive abnormalities, treatments for this symptom dimension are lacking. Here, we describe the evidence demonstrating abnormalities in social cognition in schizophrenia, major depressive disorder, and bipolar disorder, as well as the neurobiology of social cognition including the role of oxytocin. We then review clinical trials of oxytocin administration in psychotic and affective disorders and the impact of this agent on social cognition. To date, several studies have demonstrated that oxytocin may improve social cognition in schizophrenia; too few studies have been conducted in affective disorders to determine the effect of oxytocin on social cognition in these disorders. Future work is needed to clarify which aspects of social cognition may be improved with oxytocin treatment in psychotic and affective disorders.

A comparison of schizophrenia, schizoaffective disorder, and bipolar disorder: Results from the Second Australian national psychosis survey

INTRODUCTION

It remains uncertain whether schizoaffective disorder (SAD) is a discrete diagnostic entity, is a variant of either a psychotic mood disorder such as bipolar disorder (BDP) or schizophrenia (SCZ), or exists on a spectral continuum between these disorders. The present study examined whether SCZ, SAD, and BDP differed qualitatively on demographic and clinical variables based on a large Australian dataset.

METHODS

This study examined data from the Australian Survey of High Impact Psychosis (SHIP), in which 1469 of the 1825 participants in who had an ICD-10 diagnosis of SCZ (n=857), SAD (n=293), and BDP (n=319) were assessed across a broad range of variables.

RESULTS

When compared to patients with SCZ, those with SAD reported more current delusional and thought disorder symptoms, a greater number of lifetime depression, mania, and positive symptoms, and fewer negative symptoms. Relative to the BPD group, the SAD group were younger, endorsed more current positive, delusional, and thought disorder symptoms, fewer lifetime mania symptoms, more lifetime psychotic, hallucination, and delusional symptoms, and recorded lower premorbid IQ scores. Compared to patients with BPD, those with SCZ were significantly younger, endorsed more current psychotic and hallucination symptoms, fewer lifetime depression and mania symptoms, more lifetime psychotic, hallucination, and delusional symptoms, reported more negative symptoms and had lower premorbid IQ and psychosocial functioning scores.

LIMITATIONS

Validated psychometric measures of psychotic or mood symptoms were not used.

CONCLUSION

This pattern of results is consistent with the conceptualisation of a spectrum of disorders, ranging from BDP at one end, to SAD in the middle, and SCZ at the other end.

Evidence for cognitive subgroups in bipolar disorder and the influence of subclinical depression and sleep disturbances

Recent research in bipolar disorder (BD) points to the relevance and persistence of cognitive deficits even in euthymia. Up to now, the mechanisms behind why some bipolar patients (BP) do not reach their former level of cognitive performance and psychosocial functioning while others remit completely, are not understood. In this study we aimed to identify a "cognitive deficit" vs. "non-deficit" subgroup within BD by using an extensive neuropsychological test battery. The test performance of 70 euthymic outpatients (BD-I and II, recruited as a sample of convenience from our bipolar disorder programme) was compared to 70 matched, healthy controls (HC). Furthermore, we investigated the association between demographic/clinical variables and the cognitive performance of BP. As expected, our sample of euthymic BP performed significantly worse than HC in psychomotor speed, divided attention, working memory, verbal memory, word fluency and problem solving. However, 41.4% of the patients did not have any neurocognitive deficits at all, and whether or not a patient belonged to the non-deficit group was not influenced by disease severity. Instead, our results demonstrate that patients suffering from persistent sleep disturbances and sub-threshold depressive symptomatology show more severe cognitive dysfunctions. In addition, antipsychotic treatment and comorbid anxiety disorder were associated with cognitive deficits. In sum, these results suggest that a major part of cognitive impairment is due to current symptomatology, especially sleep disorder and sub-syndromal depression. Rigorous treatment of these symptoms thus might well improve cognitive deficits and, as a consequence, overall functioning in BD.

Telencephalic neurocircuitry and synaptic plasticity in rodent spatial learning and memory

Spatial learning and memory in rodents represent close equivalents of human episodic declarative memory, which is especially sensitive to cerebral aging, neurodegeneration, and various neuropsychiatric disorders. Many tests and protocols are available for use in laboratory rodents, but Morris water maze and radial-arm maze remain the most widely used as well as the most valid and reliable spatial tests. Telencephalic neurocircuitry that plays functional roles in spatial learning and memory includes hippocampus, dorsal striatum and medial prefrontal cortex. Prefrontal-hippocampal circuitry comprises the major associative system in the rodent brain, and is critical for navigation in physical space, whereas interconnections between prefrontal cortex and dorsal striatum are probably more important for motivational or goal-directed aspects of spatial learning. Two major forms of synaptic plasticity, namely long-term potentiation, a lasting increase in synaptic strength between simultaneously activated neurons, and long-term depression, a decrease in synaptic strength, have been found to occur in hippocampus, dorsal striatum and medial prefrontal cortex. These and other phenomena of synaptic plasticity are probably crucial for the involvement of telencephalic neurocircuitry in spatial learning and memory. They also seem to play a role in the pathophysiology of two brain pathologies with episodic declarative memory impairments as core symptoms, namely Alzheimer's disease and schizophrenia. Further research emphasis on rodent telencephalic neurocircuitry could be relevant to more valid and reliable preclinical research on these most devastating brain disorders. This article is part of a Special Issue entitled SI: Brain and Memory.

Lower glutamic acid decarboxylase 65-kDa isoform messenger RNA and protein levels in the prefrontal cortex in schizoaffective disorder but not schizophrenia

BACKGROUND

Altered gamma-aminobutyric acid (GABA) signaling in the prefrontal cortex (PFC) has been associated with cognitive dysfunction in patients with schizophrenia and schizoaffective disorder. Levels of the GABA-synthesizing enzyme glutamic acid decarboxylase 67-kDa isoform (GAD67) in the PFC have been consistently reported to be lower in patients with these disorders, but the status of the second GABA-synthesizing enzyme, glutamic acid decarboxylase 65-kDa isoform (GAD65), remains unclear.

METHODS

GAD65 messenger RNA (mRNA) levels were quantified in PFC area 9 by quantitative polymerase chain reaction from 62 subjects with schizophrenia or schizoaffective disorder and 62 matched healthy comparison subjects. In a subset of subject pairs, GAD65 relative protein levels were quantified by confocal immunofluorescence microscopy.

RESULTS

Mean GAD65 mRNA levels were 13.6% lower in subjects with schizoaffective disorder but did not differ in subjects with schizophrenia relative to their matched healthy comparison subjects. In the subjects with schizoaffective disorder, mean GAD65 protein levels were 19.4% lower and were correlated with GAD65 mRNA levels. Lower GAD65 mRNA and protein levels within subjects with schizoaffective disorder were not attributable to factors commonly comorbid with the diagnosis.

CONCLUSIONS

In concert with previous studies, these findings suggest that schizoaffective disorder is associated with lower levels of both GAD65 and GAD67 mRNA and protein in the PFC, whereas subjects with schizophrenia have lower mean levels of only GAD67 mRNA and protein. Because cognitive function is generally better preserved in patients with schizoaffective disorder relative to patients with schizophrenia, these findings may support an interpretation that GAD65 downregulation provides a homeostatic response complementary to GAD67 downregulation that serves to reduce inhibition in the face of lower PFC network activity.

Early-course unmedicated schizophrenia patients exhibit elevated prefrontal connectivity associated with longitudinal change

Strong evidence implicates prefrontal cortex (PFC) as a major source of functional impairment in severe mental illness such as schizophrenia. Numerous schizophrenia studies report deficits in PFC structure, activation, and functional connectivity in patients with chronic illness, suggesting that deficient PFC functional connectivity occurs in this disorder. However, the PFC functional connectivity patterns during illness onset and its longitudinal progression remain uncharacterized. Emerging evidence suggests that early-course schizophrenia involves increased PFC glutamate, which might elevate PFC functional connectivity. To test this hypothesis, we examined 129 non-medicated, human subjects diagnosed with early-course schizophrenia and 106 matched healthy human subjects using both whole-brain data-driven and hypothesis-driven PFC analyses of resting-state fMRI. We identified increased PFC connectivity in early-course patients, predictive of symptoms and diagnostic classification, but less evidence for "hypoconnectivity." At the whole-brain level, we observed "hyperconnectivity" around areas centered on the default system, with modest overlap with PFC-specific effects. The PFC hyperconnectivity normalized for a subset of the sample followed longitudinally (n = 25), which also predicted immediate symptom improvement. Biologically informed computational modeling implicates altered overall connection strength in schizophrenia. The initial hyperconnectivity, which may decrease longitudinally, could have prognostic and therapeutic implications.

The neurocognitive functioning in bipolar disorder: a systematic review of data

BACKGROUND

During the last decades, there have been many different opinions concerning the neurocognitive function in Bipolar disorder (BD). The aim of the current study was to perform a systematic review of the literature and to synthesize the data in a comprehensive picture of the neurocognitive dysfunction in BD.

METHODS

Papers were located with searches in PubMed/MEDLINE, through June 1st 2015. The review followed a modified version of the recommendations of the Preferred Items for Reporting of Systematic Reviews and Meta-Analyses statement.

RESULTS

The initial search returned 110,403 papers. After the deletion of duplicates, 11,771 papers remained for further evaluation. Eventually, 250 were included in the analysis.

CONCLUSION

The current review supports the presence of a neurocognitive deficit in BD, in almost all neurocognitive domains. This deficit is qualitative similar to that observed in schizophrenia but it is less severe. There are no differences between BD subtypes. Its origin is unclear. It seems it is an enduring component and represents a core primary characteristic of the illness, rather than being secondary to the mood state or medication. This core deficit is confounded (either increased or attenuated) by the disease phase, specific personal characteristics of the patients (age, gender, education, etc.), current symptomatology and its treatment (especially psychotic features) and long-term course and long-term exposure to medication, psychiatric and somatic comorbidity and alcohol and/or substance abuse.