Defining cognitive and functional profiles in schizophrenia and affective disorders

Comparison of cognitive performance in first-episode drug-naïve schizophrenia, bipolar II disorder, and major depressive disorder patients after treatment

BACKGROUND

Cognitive impairment is a recognized fundamental deficit in individuals diagnosed with schizophrenia (SZ), bipolar II disorder (BD II), and major depressive disorder (MDD), among other psychiatric disorders. However, limited research has compared cognitive function among first-episode drug-naïve individuals with SZ, BD II, or MDD.

METHODS

This study aimed to address this gap by assessing the cognitive performance of 235 participants (40 healthy controls, 58 SZ patients, 72 BD II patients, and 65 MDD patients) using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) before and after 12 weeks of treatment in SZ, BD II, and MDD patients. To clarify, the healthy controls only underwent RBANS testing at baseline, whereas the patient groups were assessed before and after treatment. The severity of symptoms in SZ patients was measured using the Positive and Negative Syndrome Scale (PANSS), and depression in BD II and MDD patients was assessed using the Hamilton Depression Scale-24 items (HAMD-24 items).

RESULTS

Two hundred participants completed the 12-week treatment period, with 35 participants dropping out due to various reasons. This group included 49 SZ patients, 58 BD II patients, and 53 MDD patients. Among SZ patients, significant improvements in immediate and delayed memory were observed after 12 weeks of treatment compared to their initial scores. Similarly, BD II patients showed significant improvement in immediate and delayed memory following treatment. However, there were no significant differences in RBANS scores for MDD patients after 12 weeks of treatment.

CONCLUSIONS

In conclusion, the findings of this study suggest that individuals with BD II and SZ may share similar deficits in cognitive domains. It is important to note that standardized clinical treatment may have varying degrees of effectiveness in improving cognitive function in patients with BD II and SZ, which could potentially alleviate cognitive dysfunction.

The Chinese Version of the Compensatory ADHD Behaviors Scale (CABS): A Study on Reliability, Validity, and Clinical Utility

Purpose

With the further development of attention-deficit/hyperactivity disorder (ADHD) research, more and more assessment tools related to ADHD have been used. However, there is still no measurement instrument to evaluate the compensatory behavior of ADHD in China. This study aimed to examine the reliability and validity of the Compensatory ADHD Behaviors Scale (CABS) adapted in Chinese and explore ecological characteristics in adults with ADHD using the CABS.

Patients and Methods

Data were collected from a sample of 306 adults (Mage = 26.43 years, SD = 5.32; 46.08% male). The original version CABS was translated into Chinese using the forward and backward translation procedures. Participants completed the CABS and questionnaires assessing ADHD symptoms and executive function. We utilized content validity, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and criterion validity to test the validity. Internal consistency and test-retest reliability were employed to test the reliability. Analysis of variance (ANOVA) was employed to compare ADHD subgroups based on gender, ADHD subtype, comorbidities, and medication status, while controlling for demographic variables as covariates.

Results

CABS exhibited good construct validity (two factors: present-oriented and future-oriented), content validity (content validity index: 0.98), internal consistency reliability (Cronbach's alpha coefficient: 0.85 to 0.87) and test-retest reliability (intraclass correlation coefficient: 0.59 to 0.88). The results of CFA showed acceptable fitness for each subscale. CABS demonstrated significant associations with inattention symptoms and plan/organizational abilities. Medicated ADHD individuals scored higher on future-oriented effectiveness subscale of CABS than non-medicated (F = 6.106, p = 0.014).

Conclusion

The results indicate that the Chinese CABS exhibited good validity and reliability. It can be considered a valid tool for assessing compensatory behaviors in Chinese adults with ADHD. Further research is needed to explore the connection between medication and compensatory behavior.

Verbal memory impairments in mood disorders and psychotic disorders: A systematic review of comparative studies

BACKGROUND

Mood and psychotic disorders are both associated with verbal memory impairments. Verbal memory represents an important treatment target for both disorders. However, whether the neurocognitive and neurophysiological profiles of verbal memory impairments differ between specific disorders within these two diagnostic categories and healthy controls remains unclear. The current systematic review synthesized findings from comparative studies which used behavioural and neuroimaging tasks to investigate verbal memory impairments between: (1) mood disorder, psychotic disorder, and healthy control groups; and (2) mood disorder without psychotic features, mood disorder with psychotic features, and healthy control groups.

METHODS

The search strategy combined terms related to three main concepts: 'mood disorders', 'psychotic disorders', and 'verbal memory'. Searches were executed in Embase, MEDLINE, PsycInfo, and PubMed databases. A total of 38 articles met the full eligibility criteria and were included in the final narrative synthesis. Findings were stratified by memory domain (overall composite score, verbal working memory, immediate recall, delayed recall, and recognition memory) and by illness phase (acute and non-acute).

RESULTS

Mood and psychotic disorders displayed consistent verbal memory impairments compared to healthy controls during the acute and non-acute phases. Few significant differences were identified in the literature between mood and psychotic disorders, and between mood disorders with and without psychotic features. Individuals with schizophrenia were found to have decreased immediate and delayed verbal recall performance compared to bipolar disorder groups during the acute phase. Major depressive disorder groups with psychotic features were also found to have decreased delayed verbal recall performance compared to those without psychosis during the acute phase. No consistent differences were identified between mood and psychotic disorders during the non-acute phase. Finally, preliminary evidence suggests there may be functional abnormalities in important frontal and temporal brain regions related to verbal memory difficulties in both mood and psychotic disorders.

DISCUSSION

The current findings have potential implications for the diagnosis and treatment of cognitive impairments in mood and psychotic disorders. Verbal recall memory may serve as a sensitive tool in the risk stratification of cognitive impairments for certain mood and psychotic disorders. Moreover, since no widespread differences between clinical groups were identified, the evidence supports providing targeted interventions for verbal memory, such as pharmacological and non-pharmacological interventions, through a trans-diagnostic approach in mood and psychotic disorders.

Methods to Identify Cognitive Alterations from Animals to Humans: A Translational Approach

The increasing prevalence of cognitive dysfunction and dementia in developed countries, associated with population aging, has generated great interest in characterizing and quantifying cognitive deficits in these patients. An essential tool for accurate diagnosis is cognitive assessment, a lengthy process that depends on the cognitive domains analyzed. Cognitive tests, functional capacity scales, and advanced neuroimaging studies explore the different mental functions in clinical practice. On the other hand, animal models of human diseases with cognitive impairment are essential for understanding disease pathophysiology. The study of cognitive function using animal models encompasses multiple dimensions, and deciding which ones to investigate is necessary to select the most appropriate and specific tests. Therefore, this review studies the main cognitive tests for assessing cognitive deficits in patients with neurodegenerative diseases. Cognitive tests, the most commonly used functional capacity scales, and those resulting from previous evidence are considered. In addition, the leading behavioral tests that assess cognitive functions in animal models of disorders with cognitive impairment are highlighted.

Effects of exercise on cognitive functioning in adults with serious mental illness: A meta analytic review

Cognitive performance is usually impaired in those with serious mental illness (SMI). Exercise may improve cognitive functioning, but studies examining the effects of exercise in SMI indicate heterogenous findings. To estimate the effects of exercise on cognitive outcomes in people with SMI. Randomized controlled trials evaluating the acute or chronic effects of exercise on cognitive functioning in SMI were searched from inception to December 26th, 2022 on major electronic databases. Random effect meta-analyses were conducted to assess the effects of exercise on over the cognitive domains and Standardized Mean Differences (SMD) and 95% confidence intervals (CIs) were used as the effect size measure. Funnel plots and Egger's test of effect size and the Trim and Fill procedure applied if evidence of publication bias was noted. Methodological quality was assessed using RoB 2. A total of 15 chronic (1 acute), 936 participants (46.7% women). Exercise showed large effects on reasoning and problem solving; small effects on executive functioning. Per diagnosis, exercise showed moderate positive effects on executive functioning and large effects on processing speed in people with depression; large effects on reasoning and problem solving in people with schizophrenia. The present study indicates a large beneficial effect of chronic physical exercise on reasoning and problem solving and small effects on executive functioning in people with SMI.

State of illness-dependent associations of neuro-cognition and psychopathological syndromes in a large transdiagnostic cohort

BACKGROUND

There is a lack of knowledge regarding the relationship between dimensional psychopathological syndromes and neurocognitive functions, particularly across the major psychiatric disorders (i.e., Major Depressive Disorder (MDD), Bipolar Disorder (BD), and Schizophrenia (SZ)).

METHOD

SANS, SAPS, HAMA, HAM-D, and YMRS were assessed in 1064 patients meeting DSM-IV-TR criteria for MDD, BD, SZ or schizoaffective disorder (SZA). In addition, a comprehensive neuropsychological test battery was administered. Psychopathological syndromes derived from factor analysis and present state of illness were used to explore psychopathology-cognition relationships. Correlational analyses were corrected for age, sex, verbal IQ, years of education, and DSM-IV-TR diagnosis. Age of onset and total duration of hospitalizations as proxies for illness severity were tested as moderators on the cognition - psychopathology relationship.

RESULTS

The negative syndrome, positive formal thought disorder as well as the paranoid-hallucinatory syndrome exhibited associations with neuro-cognition in an illness state-dependent manner, while the psychopathological factors depression and increased appetite only showed weak associations. Illness severity showed moderating effects on the neurocognitive-psychopathology relationship only for the negative syndrome and positive formal thought disorder.

LIMITATIONS

No healthy control subjects were entered into the analyses because of lack of variance in psychopathological symptoms, which prevents from drawing conclusions regarding the relative level of potential cognitive impairments.

CONCLUSIONS

This study suggests the relationship of neuro-cognition and psychopathology to be highly state of illness-dependent across affective and psychotic disorders. Results hint at the moderating effects of illness severity on psychopathological factors that might be more treatment resistant.

Investigation of social and cognitive predictors in non-transition ultra-high-risk' individuals for psychosis using spiking neural networks

Finding predictors of social and cognitive impairment in non-transition Ultra-High-Risk individuals (UHR) is critical in prognosis and planning of potential personalised intervention strategies. Social and cognitive functioning observed in youth at UHR for psychosis may be protective against transition to clinically relevant illness. The current study used a computational method known as Spiking Neural Network (SNN) to identify the cognitive and social predictors of transitioning outcome. Participants (90 UHR, 81 Healthy Control (HC)) completed batteries of neuropsychological tests in the domains of verbal memory, working memory, processing speed, attention, executive function along with social skills-based performance at baseline and 4 × 6-month follow-up intervals. The UHR status was recorded as Remitters, Converters or Maintained. SNN were used to model interactions between variables across groups over time and classify UHR status. The performance of SNN was examined relative to other machine learning methods. Higher interaction between social and cognitive variables was seen for the Maintained, than Remitter subgroup. Findings identified the most important cognitive and social variables (particularly verbal memory, processing speed, attention, affect and interpersonal social functioning) that showed discriminative patterns in the SNN models of HC vs UHR subgroups, with accuracies up to 80%; outperforming other machine learning models (56-64% based on 18 months data). This finding is indicative of a promising direction for early detection of social and cognitive impairment in UHR individuals that may not anticipate transition to psychosis and implicate early initiated interventions to stem the impact of clinical symptoms of psychosis.

Convergent and divergent cognitive impairment of unipolar and bipolar depression: A magnetoencephalography resting-state study

BACKGROUND

Unipolar depression (UD) and bipolar depression (BD) showed convergent and divergent cognitive impairments. Neural oscillations are linked to the foundational cognitive processes. We aimed to investigate the underpinning spectral neuronal power patterns by magnetoencephalography (MEG), which combinates high spatial and temporal resolution. We hypothesized that patients with UD and BD exhibit common and distinct patterns, which may contribute to their cognitive impairments.

METHODS

Group cognitive tests were performed. Eyes closed resting-state MEG data were collected from 61 UD, 55 BD, and 52 healthy controls (HC). Nonparametric cluster-based permutation tests were performed to deal with the multiple comparison problem on channel-frequency MEG data. Correlation analysis of cognitive dysfunction scores and MEG oscillation were conducted by Spearman or partial correlation analysis.

RESULTS

Wisconsin Card Sorting Test showed similar cognitive impairment in patients with UD and BD. Moreover, patients with BD exhibited extensive cognitive deficits in verbal executive functions and visuospatial processing. Compare to HC, both patients with UD and BD showed increased frontal-central beta power while high gamma power was decreased in UD groups during the resting-state. The significant correlations between cognitive function and average beta power were observed.

CONCLUSIONS

Patients with BD had more cognitive impairments on different dimensions than those with UD, involving disrupted beta power modulations. Our investigation provides a better understanding of the neuroelectrophysiological process underlying cognitive impairments in patients with UD and BD.

Study protocol for evaluating the clinical efficacy and neurobiological correlates of sequential treatment with tDCS primed iTBS and ECT in treatment-resistant depression

Background: Treatment-resistant depression is a burdensome condition. Intermittent theta burst stimulation (iTBS) of the left dorsolateral prefrontal cortex is considered a treatment option in early course of resistance with a proportion of such patients responding to it. Preliminary evidence suggests a role of priming iTBS stimulation with preconditioning using cathodal transcranial direct current stimulation (tDCS). This protocol describes a double-blind randomized sham-controlled study to evaluate the clinical efficacy and tolerability of tDCS-primed iTBS in the treatment of resistant depression. Non-responders to this trial will be offered open-label electroconvulsive therapy. All participants will undergo neurobiological investigations that will enable the identification of potential response predictors and mechanisms. Methods: Three hundred and fifty consenting patients with treatment resistant depression will be randomly assigned to receive 20–30 daily sessions of true-tDCS or sham-tDCS primed iTBS over left dorsolateral prefrontal cortex at three study centers. After this blinded sham-controlled trial, non-responders to the intervention will be offered open-label true ECT. Clinical assessments, neurocognitive assessments and multimodal investigations (magnetic resonance imaging, electroencephalography, heart rate variability, investigative transcranial magnetic stimulation-transcranial direct current stimulation, gene polymorphisms) will be conducted at baseline and repeated after the end of the trial, as well as open-label ECT course. The trial will evaluate the improvement in depressive symptoms (Hamilton depression rating scale) between the two groups as the primary outcome measure.

Validation of the Chinese Version of the Schizophrenia Cognition Rating Scale

OBJECTIVE

The Schizophrenia Cognition Rating Scale (SCoRS) is an interview-based assessment tool for evaluating the cognitive deficit and daily functioning of patients with schizophrenia.

METHODS

Sixty-eight patients with schizophrenia and 68 age- and sex-matched healthy individuals were recruited to validate the Chinese version of SCoRS in this study. All participants underwent cognitive assessment using the SCoRS, which was verified by the Brief Assessment of Cognition in Schizophrenia (BACS), and the UCSD Performance-based Skills Assessment, Brief Version (UPSA-B). Patients with schizophrenia were additionally assessed using the Positive and Negative Syndrome Scale (PANSS).

RESULTS

SCoRS ratings reported by patients (SCoRS-S), those reported by the interviewer (SCoRS-I), and SCoRS global scores (SCoRS-G) showed significant correlation with all subscales of the BACS and the UPSA-B. On receiver operating characteristic curve analysis, SCoRS-S, SCoRS-I, and SCoRS-G significantly differentiated patients with schizophrenia from healthy controls. Moreover, SCoRS-S and SCoRS-I ratings showed positive correlation with the negative symptoms and general symptoms of PANSS.

CONCLUSION

The Chinese version of SCoRS showed good discriminant, concurrent, and external validity, suggesting that it is a useful and convenient tool for assessment of cognitive function among Mandarin-speaking patients with schizophrenia in clinical practice.

Developing a profile of activities of daily living for bipolar disorder: a systematic review protocol and meta-analysis

INTRODUCTION

Bipolar disorder (BD) is a severe mental health disorder that affects 2% of the adult population. Individuals with this disorder are at a higher risk for morbidity and functional difficulties. They may also experience significant challenges in their activities of daily living (ADLs). This systematic review will identify all available studies that examine subsets of ADLs that impact individuals with BD.

METHODS AND ANALYSIS

MEDLINE, Embase, CINAHL and APA PsycINFO will be searched to identify observational studies that examined functioning, independence or performance across a variety of ADLs. Title and abstract, full-text screening and a risk of bias assessment will be conducted in duplicate. An overarching table that summarises the level of functioning across different ADLs or an 'ADL profile' will be developed, and if there are sufficient data, these will be separated based on the phases of BD, such as manic/hypomanic, depressed and euthymic.

ETHICS AND DISSEMINATION

As this systematic review uses information from previous literature, this review does not require ethics approval. This review will help identify the trends in daily activities that individuals struggle with and can help healthcare practitioners identify specific areas of need for support. We plan to disseminate the results in a peer-reviewed journal and conferences targeting occupational therapists and mental health clinicians.

PROSPERO REGISTRATION NUMBER

CRD42021255089.

The use of the Montreal Cognitive Assessment (MoCA) screening tool to evaluate cognitive deficits in Lebanese in-patients with schizophrenia

BACKGROUND

The Montreal Cognitive Assessment (MoCA) is a brief cognitive impairment screening tool suitable for a rapid diagnosis of cognitive functioning. The primary objective was to examine the ability of the MoCA to detect cognitive impairment and functioning (autonomy and social cognition) among Lebanese patients with schizophrenia. The secondary objective was to evaluate factors related to cognition.

METHODS

A cross-sectional study conducted between July 2019 and Mars 2020 that enrolled 120 in-patients diagnosed with schizophrenia. The MoCA tool and the BACS were used to evaluate the patients' cognitive functioning.

RESULTS

The MoCA adjusted total score was significantly correlated with the BACS total score (r = .72, p < .001). The cut-off value of the MoCA for detecting mild cognitive impairment was 21, moderate cognitive impairment was 20.50 and severe cognitive impairment was 19.5. The multivariable analysis showed that the MoCA total score and the BACS score resulted in a non-significant association with autonomy. Also, higher cognition (higher BACS) (B =.10, p < 0.001) was significantly associated with a higher MoCA total score. However, higher depression (B=-.18, p = .02) and higher psychosis (B=-.04, p = .01) were significantly associated with lower MoCA.

CONCLUSION

The Arabic version of the MoCA can be a useful tool for screening cognitive impairment in patients with schizophrenia.

Graph Analysis of Verbal Fluency Tests in Schizophrenia and Bipolar Disorder

Verbal Fluency Tests (VFT) are one of the most common neuropsychological tasks used in bipolar disorder (BD) and schizophrenia (SZ) research. Recently, a new VFT analysis method based on graph theory was developed. Interpreting spoken words as nodes and every temporal connection between consecutive words as edges, researchers created graph structures, allowing the extraction of more data from participants’ speech, called Speech Graph Attributes (SGA). The aim of our study was to compare speech graphs, derived from Phonemic and Semantic VFT, between SZ, BD, and healthy controls (HC). Twenty-nine SZ patients, twenty-nine BD patients, and twenty-nine HC performed Semantic and Phonemic VFT. Standard measures (SM) and 13 SGA were analyzed. SZ patients’ Semantic VFT graphs showed lower total word count and correct responses. Their graphs presented less nodes and edges, higher density, smaller diameter, average shortest path (ASP), and largest strongly connected component than the HC group. SM did not differentiate BD and HC groups, and patients’ Semantic VFT graphs presented smaller diameter and ASP than HC. None of the parameters differentiated BD and SZ patients. Our results encourage the use of speech graph analysis, as it reveals verbal fluency alterations that remained unnoticed in the routine comparisons of groups with the use SM.

An examination of neurocognition and theory of mind as predictors of engagement with a tailored digital therapeutic in persons with serious mental illness

There is an increasing interest in the development and implementation of digital therapeutics (apps) in individuals with serious mental illness (SMI). However, there is limited understanding of the role of neurocognition and social cognition on engagement with apps. The present study is a secondary analysis of a pilot randomized controlled trial (N = 62) comparing a tailored digital intervention to treat tobacco use disorder in individuals with SMI to a standard of care digital intervention for the general population. The purpose of this study was to examine the impact of neurocognition, social cognition, and clinical characteristics on indices of app engagement in users of the tailored app compared to users of the standard of care app. Correlational analyses demonstrated that individuals with low levels of neurocognition and social cognition engaged more often and for longer duration with the tailored app compared to the standard of care app. In a series of multilevel zero-inflated negative binomial models, assignment to the tailored app remained the most robust predictor of app interactions (Risk Ratio [RR] = 1.72; p < .01), duration of app use (RR = 6.47; p < .01), and average length of interaction (RR = 2.70; p < .01), after adjusting for key demographic and clinical characteristics, and two measures of cognition. This is one of the first studies to demonstrate that digital therapeutics can be designed to mitigate the impact of neurocognition and social cognition on device engagement in SMI populations. Recommendations are made to advance the use of new analytic models to uncover patterns of engagement with digital therapeutics.

General description of cognitive deficits in schizophrenia and assessment tools in Lebanon: A scoping review

Many cognitive functions are affected in schizophrenia patients, particularly memory, attention, motor skills, executive function, and social cognition. Cognitive assessment is one of the best indicators of the functional and social prognosis of schizophrenic patients. In Lebanon, no study has yet examined the assessment of cognitive functions in patients with neurological or psychiatric diseases. This review aims to provide an overview of the cognitive profiles of schizophrenia and describe the different cognitive tests used in Lebanon. The MEDLINE/PubMed database was used to conduct a literature review covering all studies related to cognition in psychosis patients from 1990 until March 2021. This screening resulted in 97 articles focused on cognition in psychiatric patients or cognitive tests in schizophrenia and required an in-depth analysis. The majority of measures developed to evaluate cognition in patients with schizophrenia were from Western countries, most of which are long and complex and may require several hours to administer. The number of neuropsychological tests available in Arab countries is unknown, although it is likely to be limited compared to what is available in Western countries. In Lebanon, some neuropsychological batteries have been locally used to assess cognition without being translated and validated to be adapted to the Lebanese sociocultural context. Clinicians in Lebanon underestimate the extent of cognitive impairment in schizophrenia patients as they have limited options, using untranslated tests or using translations that have not been validated. Future studies should target the development and adaptation of instruments that predict and measure cognition and functional ability.

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Many cognitive functions are generally impaired in patients with schizophrenia

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The number of neuropsychological tests available in Arab countries is unknown

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In Lebanon, some neuropsychological batteries have been used to assess cognition without being translated and validated

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Few studies conducted in Lebanon have used neurocognitive tests among schizophrenia.

Cognition and daily life functioning among persons with serious mental illness: A cluster analytic examination of heterogeneity on the Test of Grocery Shopping Skills

OBJECTIVE

To characterize variability in daily life functioning among individuals with serious mental illness based on a naturalistic performance measure of grocery shopping and standard neuropsychological tasks using cluster analytic methods.

METHODS

A naturalistic performance measure, the Test of Grocery Shopping Skills (TOGSS), and standard neuropsychological tasks, were completed by 191 participants with serious mental illness. Hierarchical cluster analytic techniques were used to explore functional subgroups based on naturalistic performance measure variables. Multivariate analyses of variance were utilized to compare subgroups on TOGSS variables and neuropsychological measures, respectively.

RESULTS

Two distinct functional subgroups emerged from the cluster analysis. On average, participants in cluster one were faster, more efficient, and more accurate compared to cluster two. Based on performance on neuropsychological tasks, cluster one had better verbal memory, visual attention, and processing speed, and executive functioning scores, compared to cluster two. The clusters did not differ on a measure of auditory working memory.

CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

Naturalistic performance measures can assist with characterizing the heterogeneity in real life functioning among people with serious mental illness. Further work to illuminate the relationship between specific cognitive abilities and specific functional abilities is warranted and may assist with targeting effective treatment plans for functional recovery. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The Impact of Negative Symptoms and Neurocognition on Functioning in MDD and Schizophrenia

Introduction: Negative symptoms, neurocognitive deficits and functional impairment are prevalent in individuals with major depressive disorder (MDD) and schizophrenia (SCZ). However, unlike neurocognitive deficits, little is known about the role of negative symptoms toward functioning in individuals with MDD. On the other hand, both factors are well-studied in individuals with SCZ. Thus, this study aimed to examine the contributions of negative symptoms and neurocognitive impairments in functioning in individuals with MDD, compared to individuals with SCZ. Methods: Participants included 50 individuals with MDD, 49 individuals with SCZ and 49 healthy controls. The following measures were administered-Negative Symptom Assessment (NSA-16), Brief Assessment of Cognition in Schizophrenia (BACS), Patient Health Questionnaire (PHQ-9), and MIRECC-Global Assessment of Functioning (MIRECC-GAF) to evaluate negative symptoms, neurocognition, depressive symptoms, and functioning respectively. Results: Both MDD and SCZ groups had significantly more severe negative symptoms, depressive symptoms, and poorer functioning than healthy controls. Individuals with SCZ performed significantly poorer on the BACS than the other two groups. Both negative symptoms and neurocognition were significantly correlated with social and occupational functioning in SCZ. Motivation subdomain of the negative symptoms was significantly correlated with occupational functioning, while depressive symptoms correlated with functioning in MDD. Conclusion: Both negative symptoms and neurocognitive deficits appear to play differential roles on individual domains of functioning between MDD and SCZ. Future longitudinal studies with larger sample sizes should be done for a better understanding about the associations between the factors and functioning.

Brain structural correlates of functional capacity in first-episode psychosis

Impaired functional capacity is a core feature of schizophrenia and presents even in first-episode psychosis (FEP) patients. Impairments in daily functioning tend to persist despite antipsychotic therapy but their neural basis is less clear. Previous studies suggest that volume loss in frontal cortex might be an important contributor, but findings are inconsistent. We aimed to comprehensively investigate the brain structural correlates of functional capacity in FEP using MRI and a reliable objective measure of functioning [University of California, San Diego Performance-Based Skills Assessment (UPSA)]. In a sample of FEP (n = 39) and a well-matched control group (n = 21), we measured cortical thickness, gray matter volume, and white matter tract integrity (fractional anisotropy, FA) within brain regions implicated by previous work. The FEP group had thinner cortex in various frontal regions and fusiform, and reduced FA in inferior longitudinal fasciculus (ILF). In FEP, poorer functional capacity correlated with reduced superior frontal volume and lower FA in left ILF. Importantly, frontal brain volumes and integrity of the ILF were identified as the structural correlates of functional capacity in FEP, controlling for other relevant factors. These findings enhance mechanistic understanding of functional capacity deficits in schizophrenia by specifying the underlying neural correlates. In future, this could help inform intervention strategies.

Dopamine Receptor Subtypes, Physiology and Pharmacology: New Ligands and Concepts in Schizophrenia

Dopamine receptors are widely distributed within the brain where they play critical modulator roles on motor functions, motivation and drive, as well as cognition. The identification of five genes coding for different dopamine receptor subtypes, pharmacologically grouped as D1- (D1 and D5) or D2-like (D2S, D2L, D3, and D4) has allowed the demonstration of differential receptor function in specific neurocircuits. Recent observation on dopamine receptor signaling point at dopamine-glutamate-NMDA neurobiology as the most relevant in schizophrenia and for the development of new therapies. Progress in the chemistry of D1- and D2-like receptor ligands (agonists, antagonists, and partial agonists) has provided more selective compounds possibly able to target the dopamine receptors homo and heterodimers and address different schizophrenia symptoms. Moreover, an extensive evaluation of the functional effect of these agents on dopamine receptor coupling and intracellular signaling highlights important differences that could also result in highly differentiated clinical pharmacology. The review summarizes the recent advances in the field, addressing the relevance of emerging new targets in schizophrenia in particular in relation to the dopamine - glutamate NMDA systems interactions.