Neuropsychological function and dysfunction in schizophrenia and psychotic affective disorders

Effects of childhood trauma on left inferior frontal gyrus function during response inhibition across psychotic disorders

BACKGROUND

Childhood trauma is a risk factor for psychosis. Deficits in response inhibition are common to psychosis and trauma-exposed populations, and associated brain functions may be affected by trauma exposure in psychotic disorders. We aimed to identify the influence of trauma-exposure on brain activation and functional connectivity during a response inhibition task.

METHODS

We used functional magnetic resonance imaging to examine brain function within regions-of-interest [left and right inferior frontal gyrus (IFG), right dorsolateral prefrontal cortex, right supplementary motor area, right inferior parietal lobule and dorsal anterior cingulate cortex], during the performance of a Go/No-Go Flanker task, in 112 clinical cases with psychotic disorders and 53 healthy controls (HCs). Among the participants, 71 clinical cases and 21 HCs reported significant levels of childhood trauma exposure, while 41 clinical cases and 32 HCs did not.

RESULTS

In the absence of effects on response inhibition performance, childhood trauma exposure was associated with increased activation in the left IFG, and increased connectivity between the left IFG seed region and the cerebellum and calcarine sulcus, in both cases and healthy individuals. There was no main effect of psychosis, and no trauma-by-psychosis interaction for any other region-of-interest. Within the clinical sample, the effects of trauma-exposure on the left IFG activation were mediated by symptom severity.

CONCLUSIONS

Trauma-related increases in activation of the left IFG were not associated with performance differences, or dependent on clinical diagnostic status; increased IFG functionality may represent a compensatory (overactivation) mechanism required to exert adequate inhibitory control of the motor response.

Predicting suicidal behaviour after first episode of non-affective psychosis: The role of neurocognitive functioning

BACKGROUND

Suicide has been recognised as one of the major causes of premature death in psychosis. However, predicting suicidal behaviour (SB) is still challenging in the clinical setting and the association of neurocognition with SB in psychosis remains poorly understood. This study aimed to investigate the role of neurocognitive performance as predictor of SB. Also, we sought to explore differences in the evolution of clinical and neurocognitive functioning between participants with/without history of suicide attempts (SA) over follow-up period.

METHODS

The sample of the study is composed by 517 patients. Sociodemographic, clinical, functional and neurocognitive measures were evaluated at baseline as well as 1-year and 3 years after first episode of psychosis. Bivariate and multivariate analyses explored the influence of these variables as putative baseline predictors of SB. Repeated measures analyses of variance tested differences in clinical and neurocognitive outcomes at 1- and 3-year follow-up.

RESULTS

Global cognitive functioning (GCF) (OR = 1.83, 95% CI = 1.25-2.67) and severe depressive symptoms (OR = 1.17, 95% CI = 1.07-1.28) predicted SB. Longitudinal analyses revealed that patients with SB at follow-up presented with higher levels of remission in terms of positive psychotic symptoms and depression. In addition, those with a history of SB had worse GCF and visual memory than those without such antecedents.

CONCLUSIONS

GCF was found to be the most robust predictor of SB along with severe depressive symptomatology. Hence, poorer cognitive performance in FEP appears to emerge as a risk factor for suicidal behaviour from early stages of the illness and a comprehensive neurocognitive assessment may contribute to risk assessment.

Cognitive and functional deficits in people with schizophrenia: Evidence for accelerated or exaggerated aging?

Cognitive and functional deficits are commonly seen in people with schizophrenia. The profile of these impairments has a resemblance to the cognitive changes seen in healthy aging. In specific, many of the cognitive ability domains that change the most with aging in healthy people are the most salient of these deficits seen in people with schizophrenia, including prominent deficits in processing speed, working memory, and episodic memory. Functional deficits seen in schizophrenia are also similar to those seen in healthy aging. There is a relationship between multiple psychotic relapses and treatment resistance and longitudinal cognitive and functional changes in schizophrenia, with this relationship starting early in the course of illness. Cognitive performance in people with schizophrenia may be consistent with accelerated or premature aging. People with schizophrenia perform similarly to healthy people who are 3 or more decades older on indices of both cognition and their everyday functional skills. Some people with schizophrenia show exaggerated cognitive changes as well. Cognitive and functional performance worsens at the outset of the illness in schizophrenia compared to premorbid functioning, meaning that these deficits are not due to development disabilities. There are multiple medical and substance abuse comorbidities in schizophrenia and although these comorbidities affect cognitive functioning, they are not completely responsible for age-related changes.

Targeting recovery in first episode psychosis: The importance of neurocognition and premorbid adjustment in a 3-year longitudinal study

INTRODUCTION

Recovery in psychotic disorders remains a major challenge across mental health. Identifying predictors of recovery in first psychotic episodes is a priority in order to increase knowledge on underlying mechanisms of the illness and to obtain objective severity markers at initial phases. In this study we gathered sociodemographic, clinical and cognitive data to explore predictive variables of recovery after three years follow-up in a sample of 399 patients with a first episode of psychosis (FEP).

MATERIAL AND METHOD

This is a longitudinal study including patients with a FEP. A dichotomic variable of recovery was created according to symptomatic and functional outcome after 3years follow-up. Significant variables in univariate analysis were entered into a binary logistic regression to obtain a multivariate prediction model of recovery.

RESULTS

The predictive model was statistically significant and classified an overall of 76% of patients correctly, specifically 86.7% of patients that would not recover and 55% of the patients that would recover. From all the variables that where significantly different between recovered and not recovered patients, only speed of processing, executive functions and premorbid adjustment were found to be significant predictors of recovery.

DISCUSSION

This study provides evidence that the degree of basal impairment in cognitive functions related to the Prefrontal Cortex and a worst premorbid adaptation predict in a significant way which patients are less likely to recover three years after a FEP.

Examining cognition across the bipolar/schizophrenia diagnostic spectrum

BACKGROUND

Cognitive impairments are well-established features of schizophrenia, but there is ongoing debate about the nature and degree of cognitive impairment in patients with schizoaffective disorder and bipolar disorder. We hypothesized that there is a spectrum of increasing impairment from bipolar disorder to schizoaffective disorder bipolar type, to schizoaffective disorder depressive type and schizophrenia.

METHODS

We compared performance on the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery between participants with schizophrenia (n = 558), schizoaffective disorder depressive type (n = 112), schizoaffective disorder type (n = 76), bipolar disorder (n = 78) and healthy participants (n = 103) using analysis of covariance with post hoc comparisons. We conducted an ordinal logistic regression to examine whether cognitive impairments followed the hypothesized spectrum from bipolar disorder (least severe) to schizophrenia (most severe). In addition to categorical diagnoses, we addressed the influence of symptom domains, examining the association between cognition and mania, depression and psychosis.

RESULTS

Cognitive impairments increased in severity from bipolar disorder to schizoaffective disorder bipolar type, to schizophrenia and schizoaffective disorder depressive type. Participants with schizophrenia and schizoaffective disorder depressive type showed equivalent performance (d = 0.07, p = 0.90). The results of the ordinal logistic regression were consistent with a spectrum of deficits from bipolar disorder to schizoaffective disorder bipolar type, to schizophrenia/schizoaffective disorder depressive type (odds ratio = 1.98, p < 0.001). In analyses of the associations between symptom dimensions and cognition, higher scores on the psychosis dimension were associated with poorer performance (B = 0.015, standard error = 0.002, p < 0.001).

LIMITATIONS

There were fewer participants with schizoaffective disorder and bipolar disorder than schizophrenia. Despite this, our analyses were robust to differences in group sizes, and we were able to detect differences between groups.

CONCLUSION

Cognitive impairments represent a symptom dimension that cuts across traditional diagnostic boundaries.

Widespread Volumetric Reductions in Schizophrenia and Schizoaffective Patients Displaying Compromised Cognitive Abilities

OBJECTIVE

Progress toward understanding brain mechanisms in psychosis is hampered by failures to account for within-group heterogeneity that exists across neuropsychological domains. We recently identified distinct cognitive subgroups that might assist in identifying more biologically meaningful subtypes of psychosis. In the present study, we examined whether underlying structural brain abnormalities differentiate these cognitively derived subgroups.

METHOD

1.5T T1 weighted structural scans were acquired for 168 healthy controls and 220 patients with schizophrenia/schizoaffective disorder. Based on previous work, 47 patients were categorized as being cognitively compromised (impaired premorbid and current IQ), 100 as cognitively deteriorated (normal premorbid IQ, impaired current IQ), and 73 as putatively cognitively preserved (premorbid and current IQ within 1 SD of controls). Global, subcortical and cortical volume, thickness, and surface area measures were compared among groups.

RESULTS

Whole cortex, subcortical, and regional volume and thickness reductions were evident in all subgroups compared to controls, with the largest effect sizes in the compromised group. This subgroup also showed abnormalities in regions not seen in the other patient groups, including smaller left superior and middle frontal areas, left anterior and inferior temporal areas and right lateral medial and inferior frontal, occipital lobe and superior temporal areas.

CONCLUSIONS

This pattern of more prominent brain structural abnormalities in the group with the most marked cognitive impairments-both currently and putatively prior to illness onset, is consistent with the concept of schizophrenia as a progressive neurodevelopmental disorder. In this group, neurodevelopmental and neurodegenerative factors may be important for cognitive function.

Cognitive deficit in patients with paranoid schizophrenia: Its clinical and laboratory correlates

The aim of this study was to search for correlates of cognitive impairment in patients with paranoid schizophrenia among clinical, demographic, anamnestic and biochemical markers (NSE, S100B protein, BDNF, hs-CRP). Patients with paranoid schizophrenia (n=125) were examined using the Brief Assessment of Cognitive Function in Schizophrenia, the Rey-Osterrieth Complex Figure task, and a number of clinical scales including the Positive and Negative Syndrome Scale. The majority of patients demonstrated cognitive impairment. The type of impairment was highly heterogeneous and individual. Relationships were found between the degree of executive functioning and family history of mental illness; working memory and age of onset of schizophrenia; and visual memory and psychopathological symptomatology. Negative and affective symptoms were not significantly associated with cognitive functioning. Treatment with first generation antipsychotics was associated with a more frequent impairment of motor skills, and concomitant anticholinergic drugs, with reduced accuracy. Use of second-generation antipsychotics only was associated with better accuracy, working memory and speech fluency. Among the patients, 21.4% had signs of a systemic inflammatory response, indicating a possible role of inflammatory response in the development of schizophrenia. CRP, S100B and NSE levels reflected features of the course of illness and therapeutic response. Patients with lower concentrations of BDNF were characterized by lower processing speeds.

Psychosis as a risk factor for suicidal thoughts and behaviors: a meta-analysis of longitudinal studies

BACKGROUND

Research has long noted higher prevalence rates of suicidal thoughts and behaviors among individuals with psychotic symptoms. Major theories have proposed several explanations to account for this association. Given the differences in the literature regarding the operationalization of psychosis and sample characteristics, a quantitative review is needed to determine to what extent and how psychosis confers risk for suicidality.

METHODS

We searched PsycInfo, PubMed, and GoogleScholar for studies published before 1 January 2016. To be included in the analysis, studies must have used at least one psychosis-related factor to longitudinally predict suicide ideation, attempt, or death. The initial search yielded 2541 studies. Fifty studies were retained for analysis, yielding 128 statistical tests.

RESULTS

Suicide death was the most commonly studied outcome (43.0%), followed by attempt (39.1%) and ideation (18.0%). The median follow-up length was 7.5 years. Overall, psychosis significantly conferred risk across three outcomes, with weighted mean ORs of 1.70 (1.39-2.08) for ideation, 1.36 (1.25-1.48) for attempt, and 1.40 (1.14-1.72) for death. Detailed analyses indicated that positive symptoms consistently conferred risk across outcomes; negative symptoms were not significantly associated with ideation, and were protective against death. Some small moderator effects were detected for sample characteristics.

CONCLUSIONS

Psychosis is a significant risk factor for suicide ideation, attempt, and death. The finding that positive symptoms increased suicide risk and negative symptoms seemed to decrease risk sheds light on the potential mechanisms for the association between psychosis and suicidality. We note several limitations of the literature and offer suggestions for future directions.

Meta-analysis of neurocognition in young psychosis patients with current cannabis use

OBJECTIVE

Adult psychosis patients (i.e. over the age of 25 years) who are also lifetime cannabis users (CANN±) appear to exhibit superior cognition compared to never-using patients (CANN-). The objective of this meta-analysis was to evaluate the cognitive differences between CANN- and patients who currently use cannabis (CANN+) (i.e. during the CANN± patients' cannabis-using stage). Specifically, focusing on young patients under the age of 25 years, the typical stage of both psychosis- and cannabis-onset.

METHOD

Of the 308 studies identified through database searches and secondary referencing, 14 compared neurocognition of CANN+ and CANN- in young people with psychotic disorders (mean age between 15 and 45 years). Effect sizes were extracted using neurocognitive test performance between CANN+ and CANN- and random effects modelling was conducted on pooled ES and moderator analyses.

RESULTS

CANN+ performed worse on several cognitive domains (i.e. premorbid IQ, current IQ, verbal learning, verbal working memory, motor inhibition) compared to CANN-. The association between age and performance in CANN+ cognition was varied, with older age predictive of worse performance in processing speed, sustained attention, verbal memory, and better performance in verbal learning and very fluency. Of note, CANN+ outperformed CANN- in tests of conceptual set-shifting.

CONCLUSION

These results are consistent with previous findings indicating that CANN+ demonstrate poorer neurocognition than CANN-; and that this is exacerbated with increasing age. Our findings demonstrate significant cognitive differences between patients with CANN+ versus CANN- even at early-onset psychosis, which could suggest a different underlying mechanism towards psychosis for cannabis users.

Relationship of executive functioning deficits to N-acetyl aspartate (NAA) and gamma-aminobutyric acid (GABA) in youth with bipolar disorder

BACKGROUND

Although cognitive deficits in bipolar disorder (BD) have been repeatedly observed, our understanding of these impairments at a mechanistic level remains limited. Few studies that investigated cognitive impairments in bipolar illness have examined the association with brain biochemistry. This pilot study utilized proton magnetic resonance spectroscopy (¹H-MRS) to evaluate the relationship between neurocognitive performance and brain metabolites in youth with BD.

METHODS

Thirty participants, twenty depressed BD participants and ten healthy comparison participants, ages 13-21, completed mood and executive function measures. ¹H-MRS data were also acquired from the anterior cingulate cortex (ACC) using two-dimensional (2D) J-resolved ¹H-MRS sequence. Proton metabolites including N-acetyl aspartate (NAA) and gamma-aminobutyric acid (GABA) were quantified for both groups.

RESULTS

Participants with BD performed significantly lower on executive functioning measures than comparison participants. There were significant positive correlations between Wisconsin Card Sorting Test (WCST) performance and NAA (p < .001) and GABA (p < .01) in the ACC in bipolar youth, such that as WCST performance increased, both NAA and GABA levels increased.

LIMITATIONS

Small sample size and lack of control for medications.

CONCLUSIONS

These findings build on previous observations of biochemical alterations associated with BD and indicate that executive functioning deficits in bipolar youth are correlated with NAA and GABA. These results suggest that cognitive deficits occur early in the course of illness and may reflect risk factors associated with altered neurochemistry. Further investigation of the relationship between brain metabolites and cognition in BD may lead to important information for developing novel, targeted interventions.

Neurocognitive subtypes in patients with bipolar disorder and their unaffected siblings

BACKGROUND

Our previous work revealed substantial heterogeneity in the cognitive profile of bipolar disorder (BD) due to the presence of three underlying cognitive subgroups characterized as: globally impaired, selectively impaired, or cognitively intact. In an effort to determine whether these subgroups are differentially related to genetic risk for the illness, we investigated whether cognitive deficits were more pronounced in unaffected siblings (UAS) of BD probands within identified clusters.

METHODS

Cluster analysis was used to identify cognitive clusters in BD (N = 60). UAS (N = 49) were classified into groups according to their proband sibling's cluster assignment; comparisons were made across all clusters and healthy controls (HCs; N = 71).

RESULTS

Three cognitive clusters in BD emerged: a globally impaired (36.7%), a selectively impaired (30%), and a cognitively intact cluster (33.3%). UAS showed a qualitatively similar pattern to their BD siblings; UAS of the globally impaired BD cluster showed verbal memory and general cognitive impairments relative to HCs. In contrast, UAS of the other two clusters did not differ from HCs.

CONCLUSIONS

This study corroborates findings from prior work regarding the presence of cognitive heterogeneity in BD. UAS of subjects in the globally impaired BD cluster presented with a qualitatively similar cognitive profile to their siblings and performed worse than all other BD clusters and UAS groups. This suggests that inherited risk factors may be contributing to cognitive deficits more notably in one subgroup of patients with BD, pointing toward differential causes of cognitive deficits in discrete subgroups of patients with the disorder.

Cognitive impairment in schizophrenia and depression: A comparison of stability and course

Cognitive deficits are clinically relevant features in schizophrenia and depression, yet little comparative data on changes in both disorders is available. This study compares cognitive performance of inpatients with schizophrenia (N = 52) and unipolar major depression (N = 67) during psychiatric treatment, assessing performance twice: after admission to hospital (acute) and prior to discharge (postacute) on average seven weeks later. A group of healthy controls was tested at comparable intervals. Data was analyzed using a multivariate linear model. Patients with schizophrenia and depression showed significantly impaired performance compared to healthy controls. On follow-up both patient groups showed improved performance. Contrary to expectation, patients with schizophrenia showed greater improvement in verbal memory, visual memory, and psychomotor speed than depressive patients. Verbal fluency presented as a possible candidate to differentiate between both disorders. Similar profiles of generalized cognitive deficits were observed in both patient-groups on acute and postacute assessment, which might indicate trait-like deficits with persistent functional implications in both disorders. Findings do not support assumptions of greater cognitive impairment in schizophrenia compared to depression. A distinction of the disorders on the grounds of cognitive functioning seems to be less specific than presumed.

Assessing Executive Dysfunction in Neurodegenerative Disorders: A Critical Review of Brief Neuropsychological Tools

Executive function (EF) has been defined as a multifaceted construct that involves a variety of high-level cognitive abilities such as planning, working memory, mental flexibility, and inhibition. Being able to identify deficits in EF is important for the diagnosis and monitoring of several neurodegenerative disorders, and thus their assessment is a topic of much debate. In particular, there has been a growing interest in the development of neuropsychological screening tools that can potentially provide a reliable quick measure of EF. In this review, we critically discuss the four screening tools of EF currently available in the literature: Executive Interview-25 (EXIT 25), Frontal Assessment Battery (FAB), INECO Frontal Screening (IFS), and FRONTIER Executive Screen (FES). We first describe their features, and then evaluate their psychometric properties, the existing evidence on their neural correlates, and the empirical work that has been conducted in clinical populations. We conclude that the four screening tools generally present appropriate psychometric properties, and are sensitive to impairments in EF in several neurodegenerative conditions. However, more research will be needed mostly with respect to normative data and neural correlates, and to determine the extent to which these tools add specific information to the one provided by global cognition screening tests. More research directly comparing the available tools with each other will also be important to establish in which conditions each of them can be most useful.

Neurocognitive Graphs of First-Episode Schizophrenia and Major Depression Based on Cognitive Features

Neurocognitive deficits are frequently observed in patients with schizophrenia and major depressive disorder (MDD). The relations between cognitive features may be represented by neurocognitive graphs based on cognitive features, modeled as Gaussian Markov random fields. However, it is unclear whether it is possible to differentiate between phenotypic patterns associated with the differential diagnosis of schizophrenia and depression using this neurocognitive graph approach. In this study, we enrolled 215 first-episode patients with schizophrenia (FES), 125 with MDD, and 237 demographically-matched healthy controls (HCs). The cognitive performance of all participants was evaluated using a battery of neurocognitive tests. The graphical LASSO model was trained with a one-vs-one scenario to learn the conditional independent structure of neurocognitive features of each group. Participants in the holdout dataset were classified into different groups with the highest likelihood. A partial correlation matrix was transformed from the graphical model to further explore the neurocognitive graph for each group. The classification approach identified the diagnostic class for individuals with an average accuracy of 73.41% for FES vs HC, 67.07% for MDD vs HC, and 59.48% for FES vs MDD. Both of the neurocognitive graphs for FES and MDD had more connections and higher node centrality than those for HC. The neurocognitive graph for FES was less sparse and had more connections than that for MDD. Thus, neurocognitive graphs based on cognitive features are promising for describing endophenotypes that may discriminate schizophrenia from depression.

Health status and mobility limitations are associated with residential and employment status in schizophrenia and bipolar disorder

INTRODUCTION

Schizophrenia (SCZ) and bipolar disorder (BP) are linked to multiple impairments in everyday functioning which share cognitive and symptom risk factors. Other risk factors for critical aspects of every day functioning (e.g., gainful employment; residential independence) such as physical health have not been evaluated, despite poor health in SCZ and BP.

METHODS

We analyzed 20-year follow-up data from the Suffolk County Mental Health Project cohort of consecutive first admissions with a psychotic disorder to 12 psychiatric facilities in Suffolk County, NY, between September 1989 and December 1995. Both 20-year symptom, health, and cognition data, and the 20-year course of weight gain were included as predictors of employment and residence status.

RESULTS

The analysis sample consisted of 122 participants with SCZ ad BP, with SCZ participants less likely to work or live independently. Correlational analyses showed symptoms and cognition predicted vocational outcomes in both samples. The effect of diagnosis was significant for both gainful employment and independence in residence. After consideration of diagnosis, mobility and negative symptoms predicted gainful employment in both samples, but there were no additional predictors of residential independence. Prospective analysis of BMI found that baseline BMI, but not changes during the 20-year follow up, predicted labor force participation.

DISCUSSION

Health status limitations were associated with residential and, particularly, employment status independent from other, previously established predictors of everyday outcomes, including cognition and symptoms. The importance of health status limitations for predicting outcome was confirmed in both SCZ and BP, with schizophrenia representing the more impaired group.

Neurocognition in patients with psychotic and non-psychotic bipolar I disorder. A comparative study with individuals with schizophrenia

BACKGROUND

It has been suggested that patients with bipolar disorder with psychotic symptoms (BD-P) have larger neurocognitive impairment than patients with bipolar disorder without a history of psychotic symptoms (BD-NP). The objective of this study was to compare neurocognitive performance of BD-P and BD-NP relative to a group of patients with schizophrenia (SZ), and healthy controls (HC).

METHODS

Neurocognitive function was examined in 100 subjects with bipolar I disorder (50 BD-P, 50 BD-NP), 50 SZ, and 51 HC. All patients with BD fulfilled criteria for euthymia, while all SZ patients were stabilised for at least the previous 3 months.

RESULTS

Patients with BD-P and BD-NP performed worse than HC in all neurocognitive measures, except for sustained attention. Differences between BD-P and BD-NP were subtle and circumscribed to the working memory domain (effect size: 0.29). SZ performed worse than BD-NP in the neurocognitive composite index (NCI) and in the working memory domain. There were no differences between SZ and BD-P in any neurocognitive measure.

LIMITATIONS

The relatively small sample size, the cross-sectional design and, that patients were receiving pharmacological treatment are the main limitations of this study.

CONCLUSIONS

Our findings show that the three groups of patients have a large neurocognitive impairment. Differences are quantitative and only present in some neurocognitive domains, such as working memory. These results suggest that patients with BD and SZ can benefit from the same strategies of cognitive remediation.

Transcriptome Alterations in Prefrontal Pyramidal Cells Distinguish Schizophrenia From Bipolar and Major Depressive Disorders

BACKGROUND

Impairments in certain cognitive processes (e.g., working memory) are typically most pronounced in schizophrenia (SZ), intermediate in bipolar disorder, and least in major depressive disorder. Given that working memory depends, in part, on neural circuitry that includes pyramidal cells in layer 3 (L3) and layer 5 (L5) of the dorsolateral prefrontal cortex (DLPFC), we sought to determine if transcriptome alterations in these neurons were shared or distinctive for each diagnosis.

METHODS

Pools of L3 and L5 pyramidal cells in the DLPFC were individually captured by laser microdissection from 19 matched tetrads of unaffected comparison subjects and subjects with SZ, bipolar disorder, and major depressive disorder, and the messenger RNA was subjected to transcriptome profiling by microarray.

RESULTS

In DLPFC L3 and L5 pyramidal cells, transcriptome alterations were numerous in subjects with SZ, but rare in subjects with bipolar disorder and major depressive disorder. The leading molecular pathways altered in subjects with SZ involved mitochondrial energy production and the regulation of protein translation. In addition, we did not find any significant transcriptome signatures related to psychosis or suicide.

CONCLUSIONS

In concert, these findings suggest that molecular alterations in DLPFC L3 and L5 pyramidal cells might be characteristic of the disease processes operative in individuals diagnosed with SZ and thus might contribute to the circuitry alterations underlying cognitive dysfunction in individuals with SZ.

Issues and developments related to assessing function in serious mental illness

Serious mental illness (SMI) results in functional disability that imposes a significant burden on individuals, caregivers, and society. Development of novel treatments is under way in an effort to improve the illness domains of cognitive impairment and negative symptoms and subsequently to improve functional outcomes. The assessment of functional outcomes in SMI faces a number of challenges, including the proliferation of assessment instruments and the differential prioritization of functional goals among stakeholder groups. Functional assessments relying on self- and informant report present a number of limitations. Identifying alternative strategies to assess functioning that are reliable, valid, and sensitive to change is necessary for use in clinical trials. Measures of functional capacity have been proposed for clinical trials investigating compounds to treat cognitive impairment in schizophrenia. Alternative approaches employing effort-based decision making or daily activity recording using instruments such as the Daily Activity Report may be more appropriate for studies focused on improving negative symptoms.

Shifting the focus toward rare variants in schizophrenia to close the gap from genotype to phenotype

Schizophrenia (SZ) is a disorder with a high heritability and a complex architecture. Several dozen genetic variants have been identified as risk factors through genome-wide association studies including large population-based samples. However, the bulk of the risk cannot be accounted for by the genes associated to date. Rare mutations have been historically seen as relevant only for some infrequent, Mendelian forms of psychosis. Recent findings, however, show that the subset of patients that present a mutation with major effect is larger than expected. We discuss some of the molecular findings of these studies. SZ is clinically and genetically heterogeneous. To identify the genetic variation underlying the disorder, research should be focused on features that are more likely a product of genetic heterogeneity. Based on the phenotypical correlations with rare variants, cognition emerges as a relevant domain to study. Cognitive disturbances could be useful in selecting cases that have a higher probability of carrying deleterious mutations, as well as on the correct ascertainment of sporadic cases for the identification of de novo variants.

Neuropsychological functioning, age, and medication adherence in bipolar disorder

Objectives

Poor adherence to medication is frequent in bipolar disorder (BD) and has been associated with several factors. To date, the relationship between low adherence and neuropsychological functioning in BD is still unclear. As age and neuropsychological functioning might have opposing influences on adherence, our aim was to investigate this link with a particular focus on the effect of age.

Methods

In a cross-sectional study, we included 353 patients divided into two age-groups (16–46; 47–71) from a French cohort diagnosed with BD (type I, II, NOS) and strictly euthymic. All patients had a standardized clinical and neuropsychological assessment and were categorized as high (n = 186) or low (n = 167) adherent based on their score from the Medication Adherence Rating Scale. Clinical information was collected based on a standardized interview and clinical validated scales. Neuropsychological performances were evaluated with an established standardized neuropsychological battery for bipolar disorder patients. After univariate analysis, neuropsychological and clinical predictors of low adherence were included in two age-specific stepwise multiple logistic regressions.

Results

A smaller number of hospitalizations (OR = 0.846, p = 0.012), a shorter illness duration (OR = 0.937, p = 0.003) and higher adverse effects (OR = 1.082, p<0.001) were associated with a greater risk of low adherence in the younger patients. In the older patients, low adherence was also predicted by a smaller number of hospitalizations (OR = 0.727, p = 0.008) and higher adverse effects (OR = 1.124, p = 0.005). Interestingly poor inhibition performance was also a significant predictor of low adherence in older patients (OR = 0.924, p = 0.030).

Conclusions

We found an age-specific relationship between cognitive functioning and adherence in patients with BD. Poor inhibition performances predicted low adherence in older patients only. Our results highlight the need to provide age-adapted therapeutic interventions to improve adherence in patients with BD.

Memory impairment and the mediating role of task difficulty in patients with schizophrenia

Using meta-analytic methods, we sought to synthesize the research literature on memory impairment in schizophrenia. Additionally, we compared performances across memory measures to determine if task difficulty (e.g., effortful encoding and retrieval vs non-effortful encoding and retrieval) could account for variance across studies. Our primary measures of interest included the California Verbal Learning Test, Wechsler Memory Scale, Rey Auditory Verbal Learning Test, Hopkins Verbal Learning Test, Rey-Osterrieth Complex Figure Test, and the Benton Visual Retention Test. We searched for all studies that met inclusion criteria using PubMed, PsycINFO, Scholars Portal Search, and Google Scholar. Studies were included if: (i) they were published after 1980; (ii) healthy controls were compared to patients with schizophrenia; (iii) at least one of the noted measures of interest was employed in the primary study; and (iv) the primary study included data that could be transformed to point estimate effect sizes (i.e., Cohen's d). Cohen's d was calculated between patients and healthy controls, along with overall 95% confidence intervals. A two-tailed independent samples t-test was conducted to assess if performance differed on various paired subtests of the same domain. Large effect sizes were found for all memory tests. No significant differences were found between subtests. In conclusion, patients with schizophrenia experience significant verbal and visual memory impairments, which are not explained by task difficulty. Patients were unable to learn or retrieve more reliably despite repetition and cuing strategies, suggesting that memory impairment in the illness is not a function of task difficulty.

Cannabis use in male and female first episode of non-affective psychosis patients: Long-term clinical, neuropsychological and functional differences

BACKGROUND

Numerous studies show the existence of a high prevalence of cannabis use among patients with psychosis. However, the differences between men and women who debut with a first episode of psychosis (FEP) regarding cannabis use have not been largely explored. The aim of this study was to identify the specific sex factors and differences in clinical evolution associated with cannabis use.

METHOD

Sociodemographic characteristics at baseline were considered in our sample of FEP patients to find differences depending on sex and the use of cannabis. Clinical, functional and neurocognitive variables at baseline, 1-year, and 3-years follow-up were also explored.

RESULTS

A total of 549 patients, of whom 43% (N = 236) were cannabis users, 79% (N = 186) male and 21% (N = 50) female, were included in the study. There was a clear relationship between being male and being a user of cannabis (OR = 5.6). Cannabis users were younger at illness onset. Longitudinal analysis showed that women significantly improved in all three dimensions of psychotic symptoms, both in the subgroup of cannabis users and in the non-users subgroup. Conversely, subgroups of men did not show improvement in the negative dimension. In cognitive function, only men presented a significant time by group interaction in processing speed, showing a greater improvement in the subgroup of cannabis users.

CONCLUSION

Despite knowing that there is a relationship between cannabis use and psychosis, due to the high prevalence of cannabis use among male FEP patients, the results showed that there were very few differences in clinical and neurocognitive outcomes between men and women who used cannabis at the start of treatment compared to those who did not.

Antioxidant effects of rice bran oil mitigate repeated haloperidol-induced tardive dyskinesia in male rats

Tardive dyskinesia (TD) is associated with the use of antipsychotic drugs such as D2 antagonist haloperidol (HP). The chronic use of HP is involved in the causation of free radicals and/or oxidative stress. In view of the nootropic, anti-anxiety, anti-inflammatory-like effects of rice bran oil (RBO) in a variety of investigations, we assessed the protective properties of RBO on HP-induced TD and neurochemical alteration. Rats treated with HP orally at a dose of 0.2 mg/kg/day for a period of 5 weeks developed VCMs which increased progressively as the treatment continued for 5 weeks. Co-administration of RBO by oral tubes at a dose of 0.4 ml/day prevented the induction of HP-induced VCMs. Repeated administration of HP increases the turnover of dopamine metabolism in the striatum. Conversely animals treated with HP + RBO decrease the metabolism of DA than water + HP treated animals. Striatal, malondieldehyde (MDA), hydrogen peroxide (H₂O₂) and antioxidant enzyme superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were also determined. It is suggested that beneficial role of RBO in attenuation of HP-induced TD. The results therefore recommended that supplementation of RBO may be useful in the HP-induced TD. The findings have also potential implication in the treatment of schizophrenia and motor disorders.

Comparison of neurocognitive function in major depressive disorder, bipolar disorder, and schizophrenia in later life: A cross-sectional study of euthymic or remitted, non-demented patients using the Japanese version of the Brief Assessment of Cognition in Schizophrenia (BACS-J)

Major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia (SZ) are associated with cognitive dysfunction both in adulthood and in later life. In this study, we directly compared neurocognitive function between these three conditions in later life, employing stringent definitions of euthymia and symptomatic remission. Cognitive function in 60 elderly outpatients with MDD, BD, or SZ (20 patients per group) was assessed using the Japanese version of the Brief Assessment of Cognition in Schizophrenia. Patients with MDD had significantly higher z scores than both the other groups with large or moderately large effect sizes, for verbal fluency, attention and speed of information processing, and composite scores. In contrast, there were no significant differences in the degree of neurocognitive impairment between patients with BD and SZ. In later life, patients with BD and SZ showed a similar degree of neurocognitive impairment, while patients with MDD showed smaller impairments in several neurocognitive domains compared to patients with either of the other two disorders.

Mapping the Consequences of Impaired Synaptic Plasticity in Schizophrenia through Development: An Integrative Model for Diverse Clinical Features

Schizophrenia is associated with alterations in sensory, motor, and cognitive functions that emerge before psychosis onset; identifying pathogenic processes that can account for this multi-faceted phenotype remains a challenge. Accumulating evidence suggests that synaptic plasticity is impaired in schizophrenia. Given the role of synaptic plasticity in learning, memory, and neural circuit maturation, impaired plasticity may underlie many features of the schizophrenia syndrome. Here, we summarize the neurobiology of synaptic plasticity, review evidence that plasticity is impaired in schizophrenia, and explore a framework in which impaired synaptic plasticity interacts with brain maturation to yield the emergence of sensory, motor, cognitive, and psychotic features at different times during development in schizophrenia. Key gaps in the literature and future directions for testing this framework are discussed.

Cognitive remediation and occupational outcome in schizophrenia spectrum disorders: A 2year follow-up study

Neurocognitive impairment is prominent in schizophrenia and a significant predictor of poor occupational outcomes. Vocational rehabilitation (VR) is frequently implemented to counteract high unemployment rates. Individuals with schizophrenia however face numerous challenges such as neurocognitive impairments and psychotic symptoms. Hence, augmenting VR to address illness-related factors may optimize occupational outcomes. The aim of this study was to examine the effects of Cognitive Remediation (CR) combined with VR(CR+VR) compared to techniques from Cognitive Behavioral Therapy (CBT) combined with VR(CBT+VR) on neurocognition and occupational functioning over a 2year period. A total of 131participants underwent assessment with the MATRICS Consensus Cognitive Battery (MCCB) at baseline, post treatment (after 10months) and follow-up (2years after randomization). Occupational status and number of hours worked were recorded at all assessment points. Both groups improved on several neurocognitive domains. All improvements were however in favor of the CR group. There was a significant increase in number of participants working and hours worked in both groups throughout the project period, with no between-group differences. Number of hours worked at follow-up was predicted by change in Working Memory and the Composite Score in the CR group. CR-augmented VR improved several domains, particularly Verbal Learning and Working Memory, which were central in the CR program. The combination of VR and CR or CBT thus enabled a significant proportion of participants to attain and maintain work.

Neural markers of emotional face perception across psychotic disorders and general population

There is considerable variation in negative and positive symptoms of psychosis, global functioning, and emotional face perception (EFP), not only in schizophrenia but also in other psychotic disorders and healthy individuals. However, EFP impairment and its association with worse symptoms and global functioning have been examined largely in the domain of schizophrenia. The present study adopted a dimensional approach to examine the association of behavioral and neural measures of EFP with symptoms of psychosis and global functioning across individuals with schizophrenia spectrum (SZ; N = 28) and other psychotic (OP; N = 29) disorders, and never-psychotic participants (NP; N = 21). Behavioral and functional MRI data were recorded as participants matched emotional expressions of faces and geometrical shapes. Lower accuracy and increased activity in early visual regions, hippocampus, and amygdala during emotion versus shape matching were associated with higher negative, but not positive, symptoms and lower global functioning, across all participants. This association remained even after controlling for group-related (SZ, OP, and NP) variance, dysphoria, and antipsychotic medication status, except in amygdala. Furthermore, negative symptoms mediated the relationship between behavioral and brain EFP measures and global functioning. This study provides some of the first evidence supporting the specific relationship of EFP measures with negative symptoms and global functioning across psychotic and never-psychotic samples, and transdiagnostically across different psychotic disorders. Present findings help bridge the gap between basic EFP-related neuroscience research and clinical research in psychosis, and highlight EFP as a potential symptom-specific marker that tracks global functioning. (PsycINFO Database Record

Improvement in Depression is Associated with Improvement in Cognition in Late-Life Psychotic Depression

OBJECTIVE

To characterize cognitive function at baseline and investigate the relationship between change in cognition, depression, and psychosis after treatment among older adults with major depressive disorder with psychotic features.

METHODS

This was a secondary analysis of a double-blind, randomized, controlled treatment trial at inpatient and outpatient settings at four academic health centers on "Young Old" (aged 60-71 years, N = 71) and "Older" (aged 72-86 years, N = 71) participants diagnosed with psychotic depression. Olanzapine plus sertraline or olanzapine plus placebo were given until week 12 or termination.

RESULTS

At baseline, Young Old and Older participants did not differ on measures of depression severity or global cognition, information processing speed, and executive function. Improvement in depressive and psychotic symptoms from baseline to treatment end was similar in both the Young Old and Older groups. However, improvement in depressive symptoms was significantly associated with improvement in global cognitive function in Young Old participants but not in Older participants.

CONCLUSION

Cognitive dysfunction was not a detriment to improvement in symptoms of psychotic major depression in our geriatric patients. Young Old and Older patients improved to a similar degree on measures of depression and delusions from baseline to treatment end. However, improvement in cognition over the course of treatment was more prominent in the Young Old group than in the Older group.

Working memory predicts presence of auditory verbal hallucinations in schizophrenia and bipolar disorder with psychosis

OBJECTIVE

The recent dramatic increase in research investigating auditory verbal hallucinations (AVHs) has broadened the former narrow focus on schizophrenia to incorporate additional populations that experience these symptoms. However, an understanding of potential shared mechanisms remains elusive. Based on theories suggesting a failure of top-down cognitive control, we aimed to compare the relationship between AVHs and cognition in two categorical diagnoses of psychosis, schizophrenia and psychotic bipolar disorder.

METHOD

A total of 124 adults aged 21-60 participated, of whom 76 had present-state psychosis (schizophrenia, n = 53; bipolar disorder with psychosis, n = 23), and 48 were non-clinical controls. Diagnosis and hallucination presence was determined using the Structured Clinical Diagnostic Interview for DSM-IV TR. AVHs severity was assessed using the Positive and Negative Syndrome Scale. Participants also completed the MATRICS cognitive battery.

RESULTS

The bipolar disorder with psychosis group performed better than the schizophrenia group for cognitive domains of Processing speed, Attention, Working memory (WM), and Visual memory. Hierarchical binary logistic regression found that WM significantly predicted presence of AVHs in both psychotic groups, but diagnosis did not significantly increase the predictive value of the model. A hierarchical multiple linear regression found that schizophrenia diagnosis was the only significant predictor of hallucination severity.

CONCLUSIONS

The findings of this study-the first, to our knowledge, to compare the relationship between AVHs and MATRICS domains across schizophrenia and bipolar disorder with psychosis-support theories that deficits in WM underly the genesis of AVHs. WM potentially represents a shared mechanism of AVHs across diagnoses, supporting dimensional classifications of these psychotic disorders. However, non-cognitive factors predictive of hallucination severity may be specific to schizophrenia.

Self versus informant reports on the specific levels of functioning scale: Relationships to depression and cognition in schizophrenia and schizoaffective disorder

The goal of the current study was to examine the relationships between insight and both cognitive function and depression in schizophrenia and schizoaffective disorder, and to determine if there were similar relationships across diagnostic categories. We examined discrepancies between self and informant reports of function on the Specific levels of function scale as a metric of insight for interpersonal, social acceptance, work and activities. We examined two samples of individuals with schizophrenia and/or schizoaffective disorder (Ns of 188 and 67 respectively). In Sample 1, cognition was measured using the Dot Probe Expectancy Task. In Sample 2, cognition was measured by averaging several subtests from the MATRICS consensus cognitive battery, as well as additional measures of working memory. In both samples, depression was measured using the Brief Psychiatric Rating Scale. In both samples, we found significant relationships between worse cognition and overestimations of work function, as well as between higher depression levels and underestimation of interpersonal function. These relationships were specific to interpersonal and work function, with significantly stronger correlations with interpersonal and work function compared to the other areas of function. Similar results were found across diagnostic categories. These results have important implications for treatment planning, as they suggest the need to take into account depression and cognitive function when evaluating the patient's self-report of function, and highlight the utility of informant reports in evaluating function and treatment planning. Further, they add to the literature on the similarity across schizophrenia and schizoaffective disorder in a variety of pathological mechanisms.

Differences of temporal dynamics and signal complexity of gamma band oscillations in first-episode psychosis during a working memory task

Gamma band oscillations participate in the temporal binding needed to synchronize cortical networks, involved in early sensory and short term memory processes. In earlier studies, alterations of these neurophysiological parameters have been found in psychotic disorders. To date no study has explored the temporal dynamics and signal complexity of gamma band oscillations in first episode psychosis (FEP). To address this issue, gamma band analysis was performed in 15 FEP patients and 18 healthy controls who successfully performed an adapted 2-back working memory task. Multiple linear and logistic regression models were computed to explore the relationship between the cognitive status and gamma oscillation changes over time. Based on regression model results, phase diagrams were constructed and their complexity was estimated using fractal dimension, a mathematical tool that describes shapes as numeric values. When adjusted for gamma values at time lags -3 to -4 ms and -15 to -16 ms, FEP patients displayed significantly higher time-dependent changes than controls, independently of the nature of the task. The present results are consistent with a discoordination of the activity of cortical generators engaged by the stimulus apparition in FEP patients, leading to a global binding deficit. In addition, fractal analysis showing higher complexity of gamma signal, confirmed this deficit. Our results provide evidence for recruitment of supplementary cortical generators as compensating mechanisms and yield further understanding for the pathophysiology cognitive impairments in FEP.

Thought Disorder in Schizophrenia and Bipolar Disorder Probands, Their Relatives, and Nonpsychiatric Controls

Thought disorder (TD) has long been associated with schizophrenia (SZ) and is now widely recognized as a symptom of mania and other psychotic disorders as well. Previous studies have suggested that the TD found in the clinically unaffected relatives of SZ, schizoaffective and bipolar probands is qualitatively similar to that found in the probands themselves. Here, we examine which quantitative measures of TD optimize the distinction between patients with diagnoses of SZ and bipolar disorder with psychotic features (BP) from nonpsychiatric controls (NC) and from each other. In addition, we investigate whether these same TD measures also distinguish their respective clinically unaffected relatives (RelSZ, RelBP) from controls as well as from each other. We find that deviant verbalizations are significantly associated with SZ and are co-familial in clinically unaffected RelSZ, but are dissociated from, and are not co-familial for, BP disorder. In contrast, combinatory thinking was nonspecifically associated with psychosis, but did not aggregate in either group of relatives. These results provide further support for the usefulness of TD for identifying potential non-penetrant carriers of SZ-risk genes, in turn enhancing the power of genetic analyses. These findings also suggest that further refinement of the TD phenotype may be needed in order to be suitable for use in genetic studies of bipolar disorder.

Neuropsychological profiles of major depressive disorder and bipolar disorder during euthymia. A systematic literature review of comparative studies

Bipolar disorder and major depressive disorder have been shown to be associated with neurocognitive abnormalities during periods of clinical remission. However, at present, there is no consensus on whether these disorders have distinctive cognitive profiles. The aim of this study was to provide an updated systematic review of studies comparing neuropsychological functioning between bipolar disorder and major depressive disorder during remission. Main findings included the following: 1) no differences regarding performances in measures of attention and processing speed, executive functions and theory of mind were found between both patient groups and 2) regarding verbal memory, preliminary evidence points towards a more defective performance in patients with bipolar disorder than those with major depressive disorder. However, several variables with negative impact on cognition (medication status, age at onset, premorbid IQ, bipolar subtype, among others) were not adequately controlled in most studies. In conclusion, evidence from studies exploring neuropsychological profiles in bipolar disorder and major depressive disorder could not provide clues to differentiate these mood disorders. Larger studies with adequate control of confounding variables would be necessary to elucidate if the finding of more defective verbal memory performance in bipolar disorder is truly explained by distinct underlying mechanisms.

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.