The NIMH-MATRICS consensus statement on negative symptoms

Intranasal Oxytocin Combined With Social Skills Training for Schizophrenia: An Add-on Randomized Controlled Trial

Some but not other studies on oxytocin for schizophrenia, particularly those using a higher dose, indicate that oxytocin improves negative symptoms of schizophrenia. We performed an add-on randomized controlled trial to examine the effect of high-dose oxytocin, social skills training, and their combination in the treatment of negative symptoms and social dysfunction in schizophrenia. Fifty-one subjects with schizophrenia were randomized, employing a two-by-two design: intranasal oxytocin (24 IU X3/day) or placebo, and social skills training or supportive psychotherapy, for 3 weeks. The primary outcome was the difference in the total score from baseline to end-of-study of a semi-structured interview which assessed patients' social interactions in 3 scenarios: sharing a positive experience, sharing a conflict, and giving support when the experimenter shared a conflict. The interactions were scored using the Coding Interactive Behavior Manual (CIB), clinical symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS). No significant difference was found between groups in the total CIB or PANSS scores. The majority of comparisons in the different social interactions between oxytocin and placebo, and between social skills training vs supportive psychotherapy, were also nonsignificant. Social skills training reduced blunted affect and gaze. In post-hoc analyses of the support interaction, oxytocin improved synchrony and decreased tension, while in the positive interaction it improved positive affect and avoidance. None of these findings remained significant when controlling for multiple comparisons. In conclusion, oxytocin did not influence participants' social behavior, and was not effective in improving the symptoms of schizophrenia. Clinicaltrials.gov Identifier: NCT01598623.

The longitudinal structure of negative symptoms in treatment resistant schizophrenia

BACKGROUND AND HYPOTHESIS

The negative symptoms of schizophrenia are strong prognostic factors but remain poorly understood and treated. Five negative symptom domains are frequently clustered into the motivation and pleasure (MAP) and emotional expression (EE) 'dimensions', but whether this structure remains stable and behaves as a single entity or not remains unclear.

STUDY DESIGN

We examined a cohort of 153 patients taking clozapine for treatment-resistant schizophrenia in a regional mental health clinic. Patients were assessed longitudinally over a mean period of 45 months using validated scales for positive, negative and mood symptoms. Network analyses were performed to identify symptom 'communities' and their stability over time. The influence of common causes of secondary negative symptoms as well as centrality measures were also examined.

STUDY RESULTS

Across patients at baseline, two distinct communities matching the clinical domains of MAP and EE were found. These communities remained highly stable and independent over time. The communities remained stabled when considering psychosis, depression, and sedation severity, and these causes of secondary negative symptoms were clustered into the MAP community. Centrality measures also remained stable over time, with similar centrality measures across symptoms.

CONCLUSIONS

Our results suggest that MAP and EE are independent dimensions that remain highly stable over time in chronic schizophrenia patients treated with clozapine. Common causes of secondary negative symptoms mapped onto the MAP dimension. Our results emphasise the need for clinical trials to address either MAP or EE, and that treating causes of secondary negative symptoms may improve MAP.

[The role of immuno-inflammatory factors in the development of negative symptoms in schizophrenia]

The literature review assessed the data obtained over the past 10 years on the relationship between inflammatory markers and the severity of negative symptoms in schizophrenia. A systematic search of the PubMed, Mendeley, and eLibrary databases was conducted in accordance with the PRISMA guidelines. Of the 407 publications found, 7 studies were selected by keywords that quantitatively assessed the relationship between the concentration of inflammatory markers and the severity of negative disorders in schizophrenia. Three publications reported statistically significant positive correlations between the level of tumor necrosis factor TNF-α and the scores of the negative subscale of the Positive and Negative Symptoms Scale (PANSS), two studies showed moderate correlations and weak correlations were reported in two publications. Two studies recorded reliable moderate and weak associations of negative symptoms with IL-1β, IL-6, IL-8, IL-10. A relationship was found between negative symptoms and the concentration of C-reactive protein, autoantibodies to neurotrophin S100b and myelin basic protein (MBP). In addition, immune-inflammatory indices of the neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and the Systemic Immune Inflammation Index (SII), which generally reflect the direction of the inflammatory response, were associated with the severity of negative disorders. The analyzed studies provided convincing data on the presence of reliable relationships between a number of cytokines and the severity of negative symptoms, which confirms previously published literature data on the pathogenetic role of neuroinflammation in the formation of negative symptoms.

Rationale and Challenges for a New Instrument for Remote Measurement of Negative Symptoms

There is a broad consensus that the commonly used clinician-administered rating scales for assessment of negative symptoms share significant limitations, including (1) reliance upon accurate self-report and recall from the patient and caregiver; (2) potential for sampling bias and thus being unrepresentative of daily-life experiences; (3) subjectivity of the symptom scoring process and limited sensitivity to change. These limitations led a work group from the International Society of CNS Clinical Trials and Methodology (ISCTM) to initiate the development of a multimodal negative symptom instrument. Experts from academia and industry reviewed the current methods of assessing the domains of negative symptoms including diminished (1) affect; (2) sociality; (3) verbal communication; (4) goal-directed behavior; and (5) Hedonic drives. For each domain, they documented the limitations of the current methods and recommended new approaches that could potentially be included in a multimodal instrument. The recommended methods for assessing negative symptoms included ecological momentary assessment (EMA), in which the patient self-reports their condition upon receipt of periodic prompts from a smartphone or other device during their daily routine; and direct inference of negative symptoms through detection and analysis of the patient's voice, appearance or activity from audio/visual or sensor-based (eg, global positioning systems, actigraphy) recordings captured by the patient's smartphone or other device. The process for developing an instrument could resemble the NIMH MATRICS process that was used to develop a battery for measuring cognition in schizophrenia. Although the EMA and other digital measures for negative symptoms are at relatively early stages of development/maturity and development of such an instrument faces substantial challenges, none of them are insurmountable.

Negative Symptoms and Their Associations With Other Clinical Variables and Working Memory Across the Schizophrenia Spectrum and Bipolar Disorder

Negative symptoms (NS) of schizophrenia spectrum disorders (SSD) are also prevalent in bipolar disorder I (BD-I) and show associations with impaired working memory (WM). However, empirical work on their relationship to other clinical factors across SSD and BD-I is sparse. Here, we characterized the associations of NS with key clinical variables and WM capacity across a combined sample of SSD and BD. We included 50 outpatients with SSD and 49 with BD-I and assessed NS domains using SANS global scores for avolition-apathy, anhedonia-asociality, alogia, and blunted affect. We assessed the transdiagnostic relationship between NS and other clinical variables, including positive symptoms, disorganization, depressive symptoms, and antipsychotic medication, using multiple regressions. The strength of these associations was further determined through dominance analyses. Finally, we used multiple regression to assess the relationship between NS domains and WM. To assess the generalizability of transdiagnostic associations, analyses were repeated in each diagnostic group separately. Across SSD and BD-I, disorganization was associated with avolition-apathy and anhedonia-asociality and depressive symptoms additionally predicted anhedonia-asociality. Antipsychotic dose was associated with blunted affect while group differences only predicted alogia. Higher avolition-apathy was related to impaired WM transdiagnostically, partially mediated by the severity of disorganization, whereas only in BD-I higher anhedonia-asociality was associated with better WM capacity. This study demonstrated transdiagnostic associations of both avolition-apathy and anhedonia-asociality with disorganization and identified avolition-apathy as a potential transdiagnostic predictor of WM impairments. Overall, our findings highlight the importance of understanding the relationship between NS domains and other clinical factors with cognitive function across SSD and BD.

Mismatch Negativity (MMN) as a Pharmacodynamic/Response Biomarker for NMDA Receptor and Excitatory/Inhibitory Imbalance-Targeted Treatments in Schizophrenia

Schizophrenia is a major mental disorder that affects approximately 0.5% of the population worldwide. Persistent negative symptoms and cognitive impairments associated with schizophrenia (CIAS) are key features of the disorder and primary predictors of long-term disability. At the neurochemical level, both CIAS and negative symptoms are potentially attributable to dysfunction or dysregulation of N-methyl-D-aspartate receptor (NMDAR)-mediated neurotransmission within cortical and subcortical brain regions. At present, there are no approved treatments for either CIAS or persistent negative symptoms. Development of novel treatments, moreover, is limited by the lack of biomarkers that can be used translationally across preclinical and early-stage clinical investigation. The present chapter describes the use of mismatch negativity (MMN) as a pharmacodynamic/response (PD/R) biomarker for early-stage clinical investigation of NMDAR targeted therapies for schizophrenia. MMN indexes dysfunction of early auditory processing (EAP) in schizophrenia. In humans, deficits in MMN generation contribute hierarchically to impaired cognition and functional outcome. Across humans, rodents, and primates, MMN has been linked to impaired NMDAR function and resultant disturbances in excitatory/inhibitory (E/I) balance involving interactions between glutamatergic (excitatory) pyramidal and GABAeric (inhibitory) local circuit neurons. In early-stage clinical trials, MMN has shown sensitivity to the acute effects of novel pharmacological treatments. These findings support use of MMN as a pharmacodynamic/response biomarker to support preclinical drug discovery and early-stage proof-of-mechanisms studies in schizophrenia and other related neuropsychiatric disorders.

The relationship between negative symptoms and MATRICS neurocognitive domains: A meta-analysis and systematic review

BACKGROUND

Negative symptoms (NS) are a core symptom domain in schizophrenia spectrum disorders and are associated with poorer social and vocational functioning, and with increased likelihood and durations of hospital admission. NS are not well understood, limiting available interventions. However, numerous studies have reported associations between neurocognitive domains and NS severity. Thus, one promising area in understanding NS is in relation to neurocognition. Currently, the specificity of the relationship between NS and neurocognition is unknown, meaning that there is no consensus regarding which neurocognitive domain is most strongly associated with NS. There is a need to systematically examine the relationship between NS and various neurocognitive domains within study samples.

METHODS

A systematic search of Ovid PsycINFO, Ovid MEDLINE and Web of Science was performed for articles published since 2004 (year of MATRICS Consensus publication). Inclusion criteria were: 1) individuals with schizophrenia spectrum disorders, first episode psychosis or clinical high risk 2) assessed all six MATRICS neurocognitive domains (processing speed, attention, working memory, verbal learning & memory, visual learning & memory, reasoning & problem solving), 3) reported correlations between all six MATRICS neurocognitive domains and global NS. A three-level random effects hierarchical meta-analysis was performed to assess the relationship between NS (global, expressive, and experiential dimensions) and the six MATRICS neurocognitive domains.

RESULTS

21 studies were included in the review (n = 3619). All MATRICS neurocognitive domains had small significant correlations with global NS (r = -0.16 to -0.20, p < 0.0001). This relationship was significantly moderated by diagnosis and the moderating effect of sex/ gender trended on significance. Analysis of a subset of the studies revealed that MATRICS neurocognitive domains also had small significant correlations with the two NS dimensions, expressive and experiential. Correlations were stronger with the expressive NS dimension.

CONCLUSIONS

This review is novel in assessing the relationship between multiple neurocognitive domains and NS within the same sample, by synthesizing close to two decades of research. Our results suggest that there is a non-specific relationship between neurocognition and NS, and that expressive NS may have a stronger relationship with neurocognitive functioning-based on the MATRICS classification of neurocognition and the neurocognitive assessments used in the included studies. This has implications on our understanding of NS and neurocognition, as well as their treatments. As we gain better understanding of the directionality of the NS-cognition relationship, it could suggest that NS, particularly in the expressive domain, could be improved by targeting cognition globally or that neurocognitive treatments could be more effective if NS are addressed first. Further implications of these results are discussed.

External validation of the five domains of negative symptoms: Focus on cognition, functional capacity, and real-world functioning

BACKGROUND

The conceptualization of negative symptoms (NS) in schizophrenia is still controversial. Recent confirmatory factor-analytic studies suggested that the bi-dimensional model (motivational deficit [MAP] and expressive deficit [EXP]) may not capture the complexity of NS structure, which could be better defined by a five-factor (five NS domains) or a hierarchical model (five NS domains as first-order factors, and MAP and EXP, as second-order factors). A validation of these models is needed to define the structure of NS. To evaluate the validity and temporal stability of the five-factor or the hierarchical structure of the brief negative symptom scale (BNSS) in individuals with schizophrenia (SCZ), exploring associations between these models with cognition, social cognition, functional capacity, and functioning at baseline and at 4 years follow-up.

METHODS

Clinical variables were assessed using state-of-the-art tools in 612 SCZ at two-time points. The validity of the five-factor and the hierarchical models was analyzed through structural equation models.

RESULTS

The two models had both a good fit and showed a similar pattern of associations with external validators at the two-time points, with minor variations. The five-factor solution had a slightly better fit. The associations with external validators favored the five-factor structure.

CONCLUSIONS

Our findings suggest that both five-factor and hierarchical models provide a valid conceptualization of NS in relation to external variables and that five-factor solution provides the best balance between parsimony and granularity to summarize the BNSS structure. This finding has important implications for the study of pathophysiological mechanisms and the development of new treatments.

Extreme deviations from the normative model reveal cortical heterogeneity and associations with negative symptom severity in first-episode psychosis from the OPTiMiSE and GAP studies

There is currently no quantifiable method to predict long-term clinical outcomes in patients presenting with a first episode of psychosis. A major barrier to developing useful markers for this is biological heterogeneity, where many different pathological mechanisms may underly the same set of symptoms in different individuals. Normative modelling has been used to quantify this heterogeneity in established psychotic disorders by identifying regions of the cortex which are thinner than expected based on a normative healthy population range. These brain atypicalities are measured at the individual level and therefore potentially useful in a clinical setting. However, it is still unclear whether alterations in individual brain structure can be detected at the time of the first psychotic episode, and whether they are associated with subsequent clinical outcomes. We applied normative modelling of cortical thickness to a sample of first-episode psychosis patients, with the aim of quantifying heterogeneity and to use any pattern of cortical atypicality to predict symptoms and response to antipsychotic medication at timepoints from baseline up to 95 weeks (median follow-ups = 4). T1-weighted brain magnetic resonance images from the GAP and OPTiMiSE samples were processed with Freesurfer V6.0.0 yielding 148 cortical thickness features. An existing normative model of cortical thickness (n = 37,126) was adapted to integrate data from each clinical site and account for effects of gender and site. Our test sample consisted of control participants (n = 149, mean age = 26, SD = 6.7) and patient data (n = 295, mean age = 26, SD = 6.7), this sample was used for estimating deviations from the normative model and subsequent statistical analysis. For each individual, the 148 cortical thickness features were mapped to centiles of the normative distribution and converted to z-scores reflecting the distance from the population mean. Individual cortical thickness metrics of +/- 2.6 standard deviations from the mean were considered extreme deviations from the norm. We found that no more than 6.4% of psychosis patients had extreme deviations in a single brain region (regional overlap) demonstrating a high degree of heterogeneity. Mann-Whitney U tests were run on z-scores for each region and significantly lower z-scores were observed in FEP patients in the frontal, temporal, parietal and occipital lobes. Finally, linear mixed-effects modelling showed that negative deviations in cortical thickness in parietal and temporal regions at baseline are related to more severe negative symptoms over the medium-term. This study shows that even at the early stage of symptom onset normative modelling provides a framework to identify individualised cortical markers which can be used for early personalised intervention and stratification.

ROI-based analysis of diffusion indices in healthy subjects and subjects with deficit or non-deficit syndrome schizophrenia

We analyzed DTI data involving 22 healthy subjects (HC), 15 patients with deficit syndrome schizophrenia (DSZ), and 25 patients with non-deficit syndrome schizophrenia (NDSZ). We used a 1.5-T MRI scanner to collect diffusion-weighted images and T1 images, which were employed to correct distortions and deformations within the diffusion-weighted images. For 156 regions of interest (ROI), we calculated the average fractional anisotropy (FA), mean diffusion (MD), and radial diffusion (RD). Each ROI underwent a group-wise comparison using permutation F-test, followed by post hoc pairwise comparisons with Bonferroni correction. In general, we observed lower FA in both schizophrenia groups compared to HC (i.e., HC>(DSZ=NDSZ)), while MD and RD showed the opposite pattern. Notably, specific ROIs with reduced FA in schizophrenia patients included bilateral nucleus accumbens, left fusiform area, brain stem, anterior corpus callosum, left rostral and caudal anterior cingulate, right posterior cingulate, left thalamus, left hippocampus, left inferior temporal cortex, right superior temporal cortex, left pars triangularis and right lingual gyrus. Significantly, the right cuneus exhibited lower FA in the DSZ group compared to other groups ((HC=NDSZ)>DSZ), without affecting MD and RD. These results indicate that compromised neural integrity in the cuneus may contribute to the pathophysiological distinctions between DSZ and NDSZ.

Emerging trends in antipsychotic and antidepressant drug development: Targeting nonmonoamine receptors and innovative mechanisms

The domain of psychiatric drug development is currently witnessing a notable transformation, with a paramount emphasis on targeting nonmonoamine receptors and exploring inventive mechanisms of action. This paper presents an overview of the ongoing advancements in antipsychotic and antidepressant drug development. Historically, antipsychotics predominantly targeted dopamine receptors, but there is now an escalating interest in drugs that act on alternative receptors, exemplified by the TAAR1 receptor. One noteworthy candidate is Ulotaront (SEP-363856), an agent acting as a TAAR1 agonist with 5-HT1A agonist activity, demonstrating promising outcomes in the treatment of schizophrenia, devoid of extrapyramidal symptoms or metabolic side-effects. Similarly, MIN-101 (Roluperidone) and KarXT are currently in development, with its focus on addressing the symptoms in schizophrenia. In the domain of antidepressants, novel therapeutic approaches have surfaced, such as Auvelity, a Food and Drug Administration (FDA)-approved NMDA receptor antagonist synergistically combined with Bupropion to enhance its effects. Another notable candidate is Zuranolone, operating as a GABA A receptor-positive allosteric modulator, showcasing efficacy in treating major depressive disorder (MDD) and postpartum depression. Additionally, TAK-653 (NBI-1065845) and MJI821 (Onfasprodil) have emerged as potential antidepressants targeting AMPA receptors and NMDA receptor 2B (NR2B) negative allosteric modulation, respectively. This paper underscores the transformative potential of these novel drug candidates in psychiatric treatment and their ability to address cases that were previously treatment-resistant. By focusing on nonmonoamine receptors and introducing innovative mechanisms, these drugs offer a promising prospect of improved outcomes for individuals suffering from schizophrenia and MDD. Thus, sustained attention and dedication to the development of such drugs are essential to augmenting the therapeutic options available for psychiatric patients.

Persistence of effort in apathy

The syndrome of apathy has generated increasing interest in recent years as systematic evaluations have revealed its high prevalence and strong negative impact on quality of life across a wide range of neurological and psychiatric conditions. However, although several theoretical models have been proposed to account for various aspects of the condition, understanding of this syndrome is still incomplete. One influential model has proposed that apathy might be described as a quantitative reduction of goal-directed behaviour in comparison to an individual's prior level of functioning. Persistence of activity defined as the capacity to continue with a task - sometimes in the face of setbacks, high levels of difficulty or fatigue - is a crucial but understudied aspect of goal-directed behaviour. Surprisingly, it has not been investigated yet in the context of apathy. Here, we provide an overview of theoretical and experimental aspects of persistence in effort that might assist to develop methods for the investigation of persistence in human behaviour, particularly within the pathologic context of apathy.

Prevalence of co-occurring severe depression and psychotic symptoms in college students and its relationship with childhood maltreatment

BACKGROUND

It has been demonstrated that childhood maltreatment (CM) is associated with an increased risk of depression and psychotic symptoms. However, there is still a lack of studies on the prevalence of co-occurring severe depression and psychotic symptoms (CSDPS) and the association between CM and CSDPS among college students.

OBJECTIVE

We aim to investigate the prevalence and demographic distribution of CSDPS among Chinese college students and to examine its relationship with CM.

PARTICIPANTS AND SETTING

A total of 7351 college students aged 18 and above completed the survey. Finally, 6854 valid questionnaires were included for further analysis.

METHODS

The Childhood Trauma Questionnaire and the item for witnessing domestic violence were used to assess the CM. The Prodromal Questionnaire-16 and the depression subscale of the Depression Anxiety and Stress-21 scale were used to assess psychotic symptoms and depressive symptoms.

RESULTS

The prevalence of CSDPS was 1.47 % among the college students. The multivariate logistic regression analysis showed that emotional abuse and emotional neglect were associated with an increased risk of CSDPS (all p < 0.05). The risk of CSDPS was dramatically increased for individuals who had experienced ≥3 types of CM (OR = 22.929, p < 0.001), as compared to those who had experienced 1-2 types of CM (OR = 4.452, p < 0.001) and those without the experience of CM.

CONCLUSION

CM was found to be associated with an increased risk of CSDPS among the college students. Notably, experiencing more types of CM was also associated with a higher risk of CSDPS.

Two and five-factor models of negative symptoms in schizophrenia are differentially associated with trait affect, defeatist performance beliefs, and psychosocial functioning

Recent factor analytic evidence supports both two-factor (motivation and pleasure, MAP; diminished expression, EXP) and five-factor (anhedonia, asociality, avolition, blunted affect, alogia) conceptualizations of negative symptoms. However, it is unclear whether these two conceptualizations of the latent structure of negative symptoms have differential associations with external correlates. The current study evaluated external correlates of the two- and five-factor structures by examining associations with variables known to have critical relations with negative symptoms: trait affect, defeatist performance beliefs, neurocognition, and community-based psychosocial functioning. Participants included a total of 245 outpatients diagnosed with schizophrenia who were rated on the Brief Negative Symptom Scale and completed a battery of additional measures during periods of clinical stability. These additional measures included the Positive and Negative Affect Schedule, Defeatist Performance Beliefs scale, MATRICS Consensus Cognitive Battery, and Level of Function Scale. Pearson correlations indicated differential patterns of associations between the BNSS scores and the external correlates. Support for the two-factor model was indicated by a stronger association of MAP with positive affect and psychosocial functioning, compared to EXP with neurocognition. Significance tests examining a differential magnitude of associations showed that the two-dimension negative symptom structure masked unique correlational relationships among the five negative symptom domains with neurocognition and social/vocational community functioning and captured unique patterns of correlation with trait affect. Support for the five-factor model was shown by a stronger association between Blunted Affect with Attention/Vigilance, and stronger associations between Avolition, Anhedonia, and Asociality with psychosocial functioning. Results offer support for both the two-dimension and five-domain model of negative symptoms as well as a hierarchical two-dimensions-five-domains model of negative symptoms. Findings may have implications for diagnostic criteria and descriptions of the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5), as well as possible treatment targets of negative symptoms.

A neuromarker for deficit syndrome in schizophrenia from a combination of structural and functional magnetic resonance imaging

AIM

Deficit schizophrenia (DS), defined by primary and enduring negative symptoms, has been proposed as a promising homogeneous subtype of schizophrenia. It has been demonstrated that unimodal neuroimaging characteristics of DS were different from non-deficit schizophrenia (NDS), however, whether multimodal-based neuroimaging features could identify deficit syndrome remains to be determined.

METHODS

Functional and structural multimodal magnetic resonance imaging of DS, NDS and healthy controls were scanned. Voxel-based features of gray matter volume, fractional amplitude of low-frequency fluctuations, and regional homogeneity were extracted. The support vector machine classification models were constructed using these features separately and jointly. The most discriminative features were defined as the first 10% of features with the greatest weights. Moreover, relevance vector regression was applied to explore the predictive values of these top-weighted features in predicting negative symptoms.

RESULTS

The multimodal classifier achieved a higher accuracy (75.48%) compared with the single modal model in distinguishing DS from NDS. The most predictive brain regions were mainly located in the default mode and visual networks, exhibiting differences between functional and structural features. Further, the identified discriminative features significantly predicted scores of diminished expressivity factor in DS but not NDS.

CONCLUSIONS

The present study demonstrated that local properties of brain regions extracted from multimodal imaging data could distinguish DS from NDS with a machine learning-based approach and confirmed the relationship between distinctive features and the negative symptoms subdomain. These findings may improve the identification of potential neuroimaging signatures and improve the clinical assessment of the deficit syndrome.

Longitudinal Investigation of Auditory Dynamic Range Deficits in Early Psychosis and its Relationship to Negative Symptoms

BACKGROUND AND HYPOTHESIS

Despite accounting for significant disease morbidity in schizophrenia, the neuropathological basis of negative symptoms remains poorly understood and options for treatment limited. Our recent study identified robust associations between diminished auditory cortex (AC) dynamic range and social functioning impairments and negative symptoms in first episode psychosis (FESz). The current investigation examined the progression of these relationships 4-8 months from baseline testing.

STUDY DESIGN

Twenty-six FESz and 38 healthy controls (HC) were tested at baseline and follow-up. Magnetoencephalography (MEG) was recorded during binaural presentation of tones (75, 80, and 85 dB). Assessments included the MATRICS cognitive consensus battery (MCCB) and Global Functioning: Role and Social scales (GFR/GFS) and the Positive and Negative Syndrome Scale.

STUDY RESULTS

Overall, FESz exhibited a blunted response to increasing tone intensity relative to HC. While this deficit did not change over time at the group level, recovery of right hemisphere AC dynamic range (85-75 dB response) among FESz individuals was associated with reductions in negative symptoms (ρ = -0.50). Diminished dynamic range was also associated with impaired GFS (ρ = 0.65), GFR (ρ = 0.51), and MCCB (ρ = 0.49) at baseline and increased negative symptoms at baseline (ρ = -0.53) and follow-up (ρ = -0.51).

CONCLUSION

Despite persistent dynamic range impairment in FESz as a group, individual recovery of this AC response property was associated with significant reduction in negative symptoms. Identification of a functional neural deficit that tracts progression of negative symptoms during a critical period for disease modification is essential to the management of these devastating and historically treatment refractory symptoms.

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

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

Evaluation of a new intrinsic and extrinsic motivation scale in youth with psychosis spectrum symptoms

BACKGROUND

Impairment in intrinsic motivation (IM), the drive to satisfy internal desires like mastery, may play a key role in disability in psychosis. However, we have limited knowledge regarding relative impairments in IM compared to extrinsic motivation (EM) or general motivation (GM), in part due to limitations in existing measures.

METHODS

Here we address this gap using a novel Trait Intrinsic and Extrinsic Motivation self-report scale in a sample of n = 243 participants including those with schizophrenia, psychosis-risk, and healthy controls. Each of the 7 IM and 6 EM items used a 7-point Likert scale assessing endorsement of dispositional statements. Bifactor analyses of these items yielded distinct IM, EM, and GM factor scores. Convergent and discriminant validity were examined in relation to General Causality Orientation Scale (GCOS-CP) and Quality of Life 3-item IM measure (QLS-IM). Utility was assessed in relation to psychosis-spectrum (PS) status and CAINS clinical amotivation.

RESULTS

IM and EM showed acceptable inter-item consistency (IM: α = 0.88; EM: α = 0.66); the bifactor model exhibited fit that varied from good to borderline to inadequate depending on the specific fit metric (SRMR = 0.038, CFI = 0.94, RMSEA = 0.106 ± 0.014). IM scores correlated with established IM measures: GCOS-CP Autonomy (rho = 0.38, p < 0.01) and QLS-IM (rho = 0.29, p < 0.01). Supporting discriminant validity, IM did not correlate with GCOS-CP Control (rho = -0.14, p > 0.05). Two-year stability in an available longitudinal subset (n = 35) was strong (IM: rho = 0.64, p < 0.01; EM: rho = 0.55, p < 0.01). Trait IM was lower in PS youth (t = 4.24, p < 0.01), and correlated with clinical amotivation (rho = -0.36, p < 0.01); EM did not show significant clinical associations.

CONCLUSIONS

These results demonstrate the clinical relevance of IM in psychosis risk. They also provide preliminary support for the reliability, validity and utility of this new Trait IM-EM scale, which addresses a measurement gap and can facilitate identification of neurobehavioral and clinical correlates of IM deficits.

Dimensional characteristics of persistent negative symptoms in schizophrenia and their relationships with schizotypy in first-degree relatives

PURPOSE OF THE ARTICLE

Schizophrenia with persistent negative symptoms (PNS) may have different characteristics regarding negative symptom dimensions and heritability patterns. This study aimed to investigate the dimensional characteristics of PNS and their relationships with schizotypal features in first-degree relatives (FDRs).

MATERIALS AND METHODS

The study included 142 patients, 142 FDRs, and 71 healthy controls (HC). Patients were evaluated with the Positive and Negative Symptom Scale (PANSS), Brief Negative Symptom Scale (BNSS), Calgary Depression Scale for Schizophrenia (CDSS), and Simpson-Angus Scale (SAS). Schizotypy Personality Questionnaire was applied to FDR and HC groups. Clinical symptoms were compared between primary-PNS, secondary-PNS, and non-PNS groups. In addition, schizotypy scores were compared between FDRs and HCs. Then, the relationship between the symptoms of the patients in the PNS group and the schizotypy scores of their relatives was evaluated by multiple regression analysis.

RESULTS

All negative symptom dimension scores were similar in primary-PNS and secondary-PNS and lowest in non-PNS. PNS-FDR had higher in all schizotypy scores than non-PNS-FDR and HC, except for lack of close friends and social anxiety. In the PNS group, positive symptom severity and PANSS experiential deficit scores significantly predicted positive and negative schizotypy scores in relatives. Negative schizotypy was associated with asociality.

CONCLUSIONS

The PNS is likely a subtype in which the genetic basis of negative symptoms is stronger and is associated with genetic abnormalities shared by positive and negative schizotypy dimensions in relatives. Family-based genetic studies will be beneficial in enlightening the genetic etiology of PNS.

Single trajectory treatment response for predominant negative symptoms: Post-hoc analysis of a clinical trial with cariprazine and risperidone

Examining the heterogeneity of negative symptoms of schizophrenia contributes to the identification of available treatment targets. Generally, prior evidence classified three to four symptom treatment response trajectory groups over the course of positive symptoms, yet, no evidence exists regarding the heterogeneity of medium-term response to predominant negative symptoms. The current post-hoc analysis aims to identify the heterogeneity in negative symptom treatment response trajectories among patients with predominant negative symptoms who received either cariprazine or risperidone for 26 weeks. Treatment response was analyzed based on the: the Positive and Negative Syndrome Scale Factor Score for Negative Symptoms (PANSS-FSNS), and the Clinical Global Impression Severity (CGIS) and Improvement (CGII) scales. To identify subgroups of patients with a similar course of treatment response, group-based trajectory modelling was utilized. Results demonstrated that in comparison with competing models, a single trajectory best described the treatment response of patients with predominant negative symptoms. The results indicate that patients with predominant negative symptoms with over ten years of schizophrenia respond rapidly to adequate treatment and follow a course of steady improvement.

Negative symptoms and cognitive impairment are associated with distinct motivational deficits in treatment resistant schizophrenia

BACKGROUND

Motivational deficits are a central feature of the negative syndrome in schizophrenia. They have consistently been associated with reduced willingness to expend physical effort in return for monetary rewards on effort based decision making (EBDM) paradigms. Nevertheless, the mechanisms underlying such altered performance are not well characterised, and it remains unclear if they are driven purely by negative symptoms, or also in part by cognitive impairment, antipsychotic treatment or even positive symptoms. Here we investigated the impact of all these factors using a paradigm that has not previously been used to measure EBDM in schizophrenia.

METHODS

Forty treatment resistant schizophrenia (TRS) patients on clozapine and matched controls (N = 80) completed a well validated EBDM task which offers monetary rewards in return for physical effort. Choice and reaction time data was analysed using logistic regressions, as well as Bayesian hierarchical drift diffusion modelling (HDDM). Behavioural parameters were compared between groups and their association with negative symptoms, cognitive function and serum clozapine levels were assessed.

RESULTS

Overall, TRS patients accepted significantly less offers than controls during effort-based decision making, suggesting they were less motivated. They demonstrated reduced sensitivity to increasing rewards, but surprisingly were also less averse to increasing effort. Despite a positive correlation between negative symptoms and cognitive function in TRS, reward sensitivity was associated only with cognitive performance. In contrast, reduced effort aversion correlated with negative symptom severity. Clozapine levels and positive symptoms were not associated with either behavioural parameter.

CONCLUSION

Motivational deficits in TRS are characterised by both diminished reward sensitivity and reduced effort aversion during EBDM. Cognitive dysfunction and negative symptom severity account for distinct aspects of these behavioural changes, despite positive associations between themselves. Overall, these findings demonstrate that negative symptoms and cognitive impairment have significant independent contributions to EBDM in TRS, thereby opening the possibility of individualised treatment targeting these mechanisms to improve motivation.

The association between early traumatic experiences and the five domains of negative symptoms in participants at clinical high risk for psychosis

AIM

Youth at clinical high risk (CHR) for psychosis have high rates of early life trauma, but it is unclear how trauma exposure impacts later negative symptom severity in CHR. The current study examined the association between early childhood trauma and the five domains of negative symptoms (anhedonia, avolition, asociality, blunted affect, alogia).

METHOD

Eighty nine participants completed interviewer-rated measures of childhood trauma and abuse experienced before age 16, psychosis risk, and negative symptoms.

RESULTS

Higher global negative symptom severity was associated with greater exposure to childhood psychological bullying, physical bullying, emotional neglect, psychological abuse, and physical abuse. Greater severity of avolition and asociality was associated with physical bullying. Greater severity of avolition was associated with emotional neglect.

CONCLUSION

Early adversity and childhood trauma is associated with negative symptoms during adolescence and early adulthood among participants at CHR for psychosis.

Psychometric properties of the Clinical Assessment Interview for Negative Symptoms (CAINS) in patients with depression and its relationship to affective symptoms

BACKGROUND

There is a conceptual overlap between negative and depressive symptoms, requiring further exploration to advance the understanding of negative symptoms. The aim of this study was to examine psychometric properties of the Clinical Assessment Interview for Negative Symptoms (CAINS) in patients with depression, and to explore the relationship between the negative and affective symptoms domains.

METHODS

Fifty-one patients with a depressive episode were included and interviewed with the CAINS and the Brief Psychiatric Rating Scale-Expanded (BPRS-E). Self-reported depressive symptoms were collected with the Montgomery-Asberg Depression Rating Scale (MADRS-S). Inter-rater agreement, internal consistency and validity measures were examined, as were correlations between negative and affective symptoms.

RESULTS

The intraclass correlation for the CAINS motivation and pleasure subscale (CAINS-MAP) was 0.98 (95% CI 0.96-0.99) and that for the expressional subscale (CAINS-EXP) was 0.81 (95% CI 0.67-0.89). Cronbach's alpha was 0.71 (95% CI 0.57-0.82) for the CAINS-MAP and 0.86 (95% CI 0.79-0.92) for the CAINS-EXP. The correlation with the negative symptoms subscale of the BPRS-E was 0.35 (p = 0.011, blinded/different raters) or 0.55 (p < 0.001, not blinded/same rater). The CAINS-MAP correlated with the affective symptoms subscale of the BPRS-E (r = 0.39, p = 0.005) and the MADRS-S total score (r = 0.50, p < 0.001), but not with anxiety symptoms.

CONCLUSIONS

Negative symptoms in depression can be assessed with the CAINS with good inter-rater agreement and acceptable internal consistency and validity. There are associations between negative and depressive symptoms that call for further exploration.

Altered brain functional networks in schizophrenia with persistent negative symptoms: an activation likelihood estimation meta-analysis

Objective

To investigate brain structural and functional characteristics of three brain functional networks including default mode network (DMN), central executive network (CEN), and salience network (SN) in persistent negative symptoms (PNS) patients.

Methods

We performed an activation likelihood estimation (ALE) meta-analysis of functional connectivity (FC) studies and voxel-based morphometry (VBM) studies to detect specific structural and functional alterations of brain networks between PNS patients and healthy controls.

Results

Seventeen VBM studies and twenty FC studies were included. In the DMN, PNS patients showed decreased gray matter in the bilateral medial frontal gyrus and left anterior cingulate gyrus and a significant reduction of FC in the right precuneus. Also, PNS patients had a decrease of gray matter in the left inferior parietal lobules and medial frontal gyrus, and a significant reduction of FC in the bilateral superior frontal gyrus in the CEN. In comparison with healthy controls, PNS patients exhibited reduced gray matter in the bilateral insula, anterior cingulate gyrus, left precentral gyrus and right claustrum and lower FC in these brain areas in the SN, including the left insula, claustrum, inferior frontal gyrus and extra-nuclear.

Conclusion

This meta-analysis reveals brain structural and functional imaging alterations in the three networks and the interaction among these networks in PNS patients, which provides neuroscientific evidence for more personalized treatment.Systematic Review RegistrationThe PROSPERO (https://www.crd.york.ac.uk/PROSPERO/, registration number: CRD42022335962).

Assessment of interrelationships between cognitive performance, symptomatic manifestation and social functioning in the acute and clinical stability phase of schizophrenia: insights from a network analysis

BACKGROUND

It has been shown that various aspects of clinical manifestation of schizophrenia are strongly related to social functioning. However, it remains unknown as to whether similar factors predict social functioning at various stages of psychosis. Therefore, the present study aimed to compare the effects of interconnections between various domains of psychopathology and neurocognition on social functioning in people during acute phase of psychosis and those during remission of positive and disorganization symptoms using a network analysis.

METHODS

Two independent samples of individuals with schizophrenia spectrum disorders were enrolled (89 inpatients during acute phase and 90 outpatients during remission of positive and disorganization symptoms). Clinical assessment covered the levels of functioning, positive, negative and depressive symptoms. Cognition was recorded using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Data were analyzed by means of the network analysis. Two separate networks of clinical symptoms, social functioning, and cognition (i.e., in patients during acute phase of psychosis and remitted outpatients with schizophrenia) were analyzed and compared with respect to the measures of centrality (betweenness, closeness, strength, and expected influence) and edge weights.

RESULTS

In both networks, the majority of centrality metrics (expected influence, strength, and closeness) had the highest values for the RBANS scores of attention (the sum of scores from two tasks, i.e., digit span and coding) and immediate memory. In both networks, social functioning was directly connected to positive, negative and depressive symptoms as well as the RBANS scores of attention and language. Additionally, in remitted patients, social functioning was directly connected to the RBANS score of immediate memory.

CONCLUSIONS

Findings from the present study indicate the central role of cognitive deficits, especially those related to attention, processing speed, working and immediate memory in shaping functional impairments regardless of schizophrenia phase. Therapeutic interventions that aim to improve functional capacity need to target these domains of neurocognitive performance.

Negative symptoms and sex differences in first episode schizophrenia: What's their role in the functional outcome? A longitudinal study

INTRODUCTION

Negative symptoms (NS) include asociality, avolition, anhedonia, alogia, and blunted affect and are linked to poor prognosis. It has been suggested that they reflect two different factors: diminished expression (EXP) (blunted affect and alogia) and amotivation/pleasure (MAP) (anhedonia, avolition, asociality). The aim of this article was to examine potential sex differences among first-episode schizophrenia (FES) patients and analyze sex-related predictors of two NS symptoms factors (EXP and MAP) and functional outcome.

MATERIAL AND METHODS

Two hundred and twenty-three FES (71 females and 152 males) were included and evaluated at baseline, six-months and one-year. Repeated measures ANOVA was used to examine the effects of time and sex on NS and a multiple linear regression backward elimination was performed to predict NS factors (MAP-EXP) and functioning.

RESULTS

Females showed fewer NS (p=0.031; Cohen's d=-0.312), especially those related to EXP (p=0.024; Cohen's d=-0.326) rather than MAP (p=0.086), than males. In both male and female group, worse premorbid adjustment and higher depressive symptoms made a significant contribution to the presence of higher deficits in EXP at one-year follow-up, while positive and depressive symptoms predicted alterations in MAP. Finally, in females, lower deficits in MAP and better premorbid adjustment predicted better functioning at one-year follow-up (R2=0.494; p<0.001), while only higher deficits in MAP predicted worse functioning in males (R2=0.088; p=0.012).

CONCLUSIONS

Slightly sex differences have been found in this study. Our results lead us to consider that early interventions of NS, especially those focusing on motivation and pleasure symptoms, could improve functional outcomes.

The structure stability of negative symptoms: longitudinal network analysis of the Brief Negative Symptom Scale in people with schizophrenia

BACKGROUND

The structure of negative symptoms of schizophrenia is still a matter of controversy. Although a two-dimensional model (comprising the expressive deficit dimension and the motivation and pleasure dimension) has gained a large consensus, it has been questioned by recent investigations.

AIMS

To investigate the latent structure of negative symptoms and its stability over time in people with schizophrenia using network analysis.

METHOD

Negative symptoms were assessed in 612 people with schizophrenia using the Brief Negative Symptom Scale (BNSS) at baseline and at 4-year follow-up. A network invariance analysis was conducted to investigate changes in the network structure and strength of connections between the two time points.

RESULTS

The network analysis carried out at baseline and follow-up, supported by community detection analysis, indicated that the BNSS's items aggregate to form four or five distinct domains (avolition/asociality, anhedonia, blunted affect and alogia). The network invariance test indicated that the network structure remained unchanged over time (network invariance test score 0.13; P = 0.169), although its overall strength decreased (6.28 at baseline, 5.79 at follow-up; global strength invariance test score 0.48; P = 0.016).

CONCLUSIONS

The results lend support to a four- or five-factor model of negative symptoms and indicate overall stability over time. These data have implications for the study of pathophysiological mechanisms and the development of targeted treatments for negative symptoms.

Social Psychopharmacology: Novel Approaches to Treat Deficits in Social Motivation in Schizophrenia

BACKGROUND AND HYPOTHESIS

Diminished social motivation is a negative symptom of schizophrenia and leads to severe functional consequences for many patients suffering from the illness. However, there are no effective medications available to treat this symptom. Despite the lack of approved treatments for patients, there is a growing body of literature on the effects of several classes of drugs on social motivation in healthy volunteers that may be relevant to patients. The aim of this review is to synthesize these results in an effort to identify novel directions for the development of medications to treat reduced social motivation in schizophrenia.

STUDY DESIGN

In this article, we review pharmacologic challenge studies addressing the acute effects of psychoactive drugs on social motivation in healthy volunteers and consider how these findings may be applied to deficits in social motivation in schizophrenia. We include studies testing amphetamines and 3,4-methylenedioxymethamphetamine (MDMA), opioids, cannabis, serotonergic psychedelics, antidepressants, benzodiazepines, and neuropeptides.

STUDY RESULTS

We report that amphetamines, MDMA, and some opioid medications enhance social motivation in healthy adults and may represent promising avenues of investigation in schizophrenia.

CONCLUSIONS

Given the acute effects of these drugs on behavioral and performance-based measures of social motivation in healthy volunteers, they may be particularly beneficial as an adjunct to psychosocial training programs in patient populations. It remains to be determined how these medications affect patients with deficits in social motivation, and in which contexts they may be most effectively administered.

Dissecting Schizotypy and Its Association With Cognition and Polygenic Risk for Schizophrenia in a Nonclinical Sample

Schizotypy is a multidimensional construct that captures a continuum of risk for developing schizophrenia-spectrum psychopathology. Existing 3-factor models of schizotypy, consisting of positive, negative, and disorganized dimensions have yielded mixed evidence of genetic continuity with schizophrenia using polygenic risk scores. Here, we propose an approach that involves splitting positive and negative schizotypy into more specific subdimensions that are phenotypically continuous with distinct positive symptoms and negative symptoms recognized in clinical schizophrenia. We used item response theory to derive high-precision estimates of psychometric schizotypy using 251 self-report items obtained from a non-clinical sample of 727 (424 females) adults. These subdimensions were organized hierarchically using structural equation modeling into 3 empirically independent higher-order dimensions enabling associations with polygenic risk for schizophrenia to be examined at different levels of phenotypic generality and specificity. Results revealed that polygenic risk for schizophrenia was associated with variance specific to delusional experiences (γ = 0.093, P = .001) and reduced social interest and engagement (γ = 0.076, P = .020), and these effects were not mediated via the higher-order general, positive, or negative schizotypy factors. We further fractionated general intellectual functioning into fluid and crystallized intelligence in 446 (246 females) participants that underwent onsite cognitive assessment. Polygenic risk scores explained 3.6% of the variance in crystallized intelligence. Our precision phenotyping approach could be used to enhance the etiologic signal in future genetic association studies and improve the detection and prevention of schizophrenia-spectrum psychopathology.

Development and Validation of the Negative Symptom Inventory-Psychosis Risk

BACKGROUND AND HYPOTHESES

Early identification and prevention of psychosis is limited by the availability of tools designed to assess negative symptoms in those at clinical high-risk for psychosis (CHR). To address this critical need, a multi-site study was established to develop and validate a clinical rating scale designed specifically for individuals at CHR: The Negative Symptom Inventory-Psychosis Risk (NSI-PR).

STUDY DESIGN

The measure was developed according to guidelines recommended by the NIMH Consensus Conference on Negative Symptoms using a transparent, iterative, and data-driven process. A 16-item version of the NSI-PR was designed to have an overly inclusive set of items and lengthier interview to support the ultimate intention of creating a new briefer measure. Psychometric properties of the 16-item NSI-PR were evaluated in a sample of 218 CHR participants.

STUDY RESULTS

Item-level analyses indicated that men had higher scores than women. Reliability analyses supported internal consistency, inter-rater agreement, and temporal stability. Associations with measures of negative symptoms and functioning supported convergent validity. Small correlations with positive, disorganized, and general symptoms supported discriminant validity. Structural analyses indicated a 5-factor structure (anhedonia, avolition, asociality, alogia, and blunted affect). Item response theory identified items for removal and indicated that the anchor range could be reduced. Factor loadings, item-level correlations, item-total correlations, and skew further supported removal of certain items.

CONCLUSIONS

These findings support the psychometric properties of the NSI-PR and guided the creation of a new 11-item NSI-PR that will be validated in the next phase of this multi-site scale development project.

Alterations in facial expressions in individuals at risk for psychosis: a facial electromyography approach using emotionally evocative film clips

BACKGROUND

Negative symptoms such as blunted facial expressivity are characteristic of schizophrenia. However, it is not well-understood if and what abnormalities are present in individuals at clinical high-risk (CHR) for psychosis.

METHODS

This experimental study employed facial electromyography (left zygomaticus major and left corrugator supercilia) in a sample of CHR individuals (N = 34) and healthy controls (N = 32) to detect alterations in facial expressions in response to emotionally evocative film clips and to determine links with symptoms.

RESULTS

Findings revealed that the CHR group showed facial blunting manifested in reduced zygomatic activity in response to an excitement (but not amusement, fear, or sadness) film clip compared to controls. Reductions in zygomatic activity in the CHR group emerged in response to the emotionally evocative peak period of the excitement film clip. Lower zygomaticus activity during the excitement clip was related to anxiety while lower rates of change in zygomatic activity during the excitement video clip were related to higher psychosis risk conversion scores.

CONCLUSIONS

Together, these findings inform vulnerability/disease driving mechanisms and biomarker and treatment development.

The mediating role of negative symptoms in "secondary factors" determining social functioning in chronic schizophrenia

Background

Chronic schizophrenia is significantly influenced by negative symptoms, with several known contributors to secondary negative symptoms. However, the impact of these factors and negative symptoms on social functioning warrants further exploration.

Methods

We assessed the clinical symptoms, antipsychotic adverse reactions, and social functioning of 283 hospitalized patients with chronic schizophrenia using various standardized interviews and scales. We conducted multiple regression and mediation analyses to elucidate the impact of secondary factors on negative symptoms, and the relationship among these "secondary factors," negative symptoms, and social functioning.

Results

Our findings identified depressive symptoms, extrapyramidal symptoms, and positive symptoms as significant contributors to secondary negative symptoms. We found that negative symptoms play a notable mediating role in the effect of depressive and positive symptoms on social functioning. However, the relationship between positive symptoms, negative symptoms, and social functioning proved to be intricate.

Conclusion

Our findings propose that negative symptoms act as pivotal mediators in the correlation between "secondary factors" (including the depressive symptoms and positive symptoms) and social functioning. The treatment of chronic schizophrenia necessitates focusing on key factors such as depressive and positive symptoms, which might significantly contribute to the development of secondary negative symptoms. Further research is essential to clarify the complex relationship among positive symptoms, negative symptoms, and social functioning in schizophrenia.

Exploring negative symptoms heterogeneity in patients diagnosed with schizophrenia and schizoaffective disorder using cluster analysis

BACKGROUND

Dissecting the heterogeneity of schizophrenia may help foster progress in understanding its etiology and lay the groundwork for the development of new treatment options for primary or enduring negative symptoms (NS). In this regard, the present study aimed to: (1) to use cluster analysis to identify subgroups of Lebanese patients diagnosed with either schizophrenia or schizoaffective disorder based on NS clusters, and (2) to relate the statistically-derived subgroups to clinically relevant external validators (including measures if state and trait depression, stigma, insight, loneliness, social support).

METHOD

A total of 202 adult long-stay, chronic, and clinically remitted patients (166 diagnosed with schizophrenia and 36 with schizoaffective disorder) were enrolled. A cluster analysis approach was adopted to classify patients based on the five NS domains social withdrawal, emotional withdrawal, alogia, avolition and anhedonia.

RESULTS

A three-cluster solution was obtained based on unique NS profiles, and divided patients into (1) low NS (LNS; 42.6%) which characterized by the lowest mean scores in all NS domains, (2) moderate NS (MNS; 25.7%), and (3) high NS (HNS; 31.7%). Post-hoc comparisons showed that depression (state and trait), loneliness and social support could accurately distinguish the schizophrenia subgroups. Additionally, individuals in the HNS cluster had longer duration of illness, longer duration of hospitalization, and were given higher dosages of antipsychotic medication compared to those in the other clusters, but these differences did not achieve the statistical significance.

CONCLUSION

Findings provide additional support to the categorical model of schizophrenia by confirming the existence of three alternate subtypes based on NS. The determination of distinct NS subgroups within the broad heterogeneous population of people diagnosed with schizophrenia may imply that each subgroup possibly has unique underlying mechanisms and necessitates different treatment approaches.

Resting-state perfusion in motor and fronto-limbic areas is linked to diminished expression of emotion and speech in schizophrenia

Negative symptoms (NS) are a core component of schizophrenia affecting community functioning and quality of life. We tested neural correlates of NS considering NS factors and consensus subdomains. We assessed NS using the Clinical Assessment Interview for Negative Symptoms and the Scale for Assessment of Negative Symptoms. Arterial spin labeling was applied to measure resting-state cerebral blood flow (rCBF) in 47 schizophrenia patients and 44 healthy controls. Multiple regression analyses calculated the relationship between rCBF and NS severity. We found an association between diminished expression (DE) and brain perfusion within the cerebellar anterior lobe and vermis, and the pre-, and supplementary motor area. Blunted affect was linked to fusiform gyrus and alogia to fronto-striatal rCBF. In contrast, motivation and pleasure was not associated with rCBF. These results highlight the key role of motor areas for DE. Considering NS factors and consensus subdomains may help identifying specific pathophysiological pathways of NS.

Negative symptoms in schizophrenia: Newly emerging measurements, pathways, and treatments

The negative symptoms of schizophrenia, which often appear earlier than any other symptom, are prominent and clinically relevant in the majority of patients. As a result, interest in their treatment has increased. Patients who exhibit significant negative symptoms have worse functional outcomes than those without, resulting in impairments in occupational, household, and recreational functioning, as well as difficulties in relationships. Yet treatment with currently available medications does not lead to any significant improvements in this core component of schizophrenia. An increased understanding of the pathophysiology underlying negative symptoms and the discovery of novel treatments that do not directly target dopamine offer the potential to develop therapies that may reduce negative symptoms and increase quality of life for patients. The current article will discuss the impact of negative symptoms, outline current measurement tools for the assessment of negative symptoms, and examine how these measures may be improved. Insights into the neural circuitry underlying negative symptoms will be discussed, and promising targets for the development of effective treatments for these symptoms will be identified. As more prospective, large-scale, randomized studies focus on the effects of treatments on negative symptoms, progress in this area is foreseeable. However, improvements in clinical assessment instruments, a better understanding of the underlying neural mechanisms, development of novel treatments with varied targets, and a greater focus on personalized treatment are all important to produce significant benefits for patients with negative symptoms of schizophrenia.

The Brief negative Symptom Scale (BNSS): a systematic review of measurement properties

BACKGROUND

Negative symptoms of schizophrenia are linked with poor functioning and quality of life. Therefore, appropriate measurement tools to assess negative symptoms are needed. The NIMH-MATRICS Consensus defined five domains for negative symptoms, which The Brief Negative Symptom Scale (BNSS) covers.

METHODS

We used the COSMIN guidelines for systematic reviews to evaluate the quality of psychometric data of the BNSS scale as a Clinician-Rated Outcome Measure (ClinROM).

RESULTS

The search strategy resulted in the inclusion of 17 articles. When using the risk of bias checklist, there was a generally good quality in reporting of structural validity and hypothesis testing. Internal consistency, reliability and cross-cultural validity were of poorer quality. ClinROM development and content validity showed inadequate results. According to the updated criteria of good measurement properties, structural validity, internal consistency and interrater reliability showed good results, while hypothesis testing showed poorer results. Cross-cultural validity and test-retest reliability were indeterminate. The updated GRADE approach resulted in a moderate grade.

CONCLUSIONS

We can potentially recommend the use of the BNSS as a concise tool to rate negative symptoms. Due to weaknesses in certain domains further validations are warranted.

Impact of cognitive performance and negative symptoms on psychosocial functioning in Czech schizophrenia patients

Schizophrenia has a profound influence on the real-life functioning of patients. There are several factors inherent to the disease course affecting the level of psychosocial functioning. Our study focused on the impact of cognitive deficit and severity of negative symptoms (i.e., the experiential domain (avolition, asociality, and anhedonia) and the expressive domain (blunted affect and alogia)) to explore psychosocial functioning in schizophrenia. Schizophrenia patients (n = 211) were tested for the presence of cognitive impairment using the NIMH-MATRICS: Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Cattery (MCCB; MATRICS Consensus Cognitive Battery) and the extent of negative symptoms using the PANSS (PANSS; Positive and Negative Syndrome Scale-selected items). The level of psychosocial functioning was measured with the Personal and Social Performance Scale (PSP). The path analysis using three regression models was used to analyse variables influencing psychosocial functioning (PSP). One of these models analyzed influence of cognitive functioning (MCCB) and negative schizophrenia symptoms (PANSS selected items reflecting expressive and experiential deficits) as predictors and NART/CRT and disease length as confounders. R² was 0.54. The direct effect of the MCCB (β = 0.09) on the PSP was suppressed by the strong effect of the negative symptoms (β = -0.64). The presence of cognitive deficits and negative symptoms in our sample of schizophrenia patients significantly influences the level of their psychosocial functioning, a key factor in remission and recovery.

Childhood trauma, perceived stress and anhedonia in individuals at clinical high risk for psychosis: multigroup mediation analysis

BACKGROUND

Evidence suggests that both childhood trauma and perceived stress are risk factors for the development of psychosis, as well as negative symptoms such as anhedonia. Previous findings link increases in perceived stress to anhedonia in individuals at clinical high risk for psychosis (CHR) and depression; however, the role of childhood trauma in this relationship has not yet been explored, despite consistent evidence that it is associated with sensitisation to later stress.

AIMS

To examine whether perceived stress mediates the relationship between childhood trauma and anhedonia in a group of youth at CHR as well as in controls (groups with depression and with no diagnosed mental health concerns).

METHOD

The study used multigroup mediation to examine the indirect effects of childhood trauma on anhedonia via perceived stress in CHR (n = 117) and depression groups (n = 284) and non-psychiatric controls (n = 124).

RESULTS

Perceived stress mediated the relationship between childhood trauma and consummatory anhedonia regardless of group status. Perceived stress mediated the relationship between childhood trauma and anticipatory anhedonia for the CHR and depression groups, but not for non-psychiatric controls. Further, groups differed in the magnitude of this relationship, with the effects trending towards stronger for those in the CHR group.

CONCLUSIONS

Our findings suggest a potential transdiagnostic pathway through which childhood trauma contributes to anhedonia across severe mental illness.

YBX1-Mediated DNA Methylation-Dependent SHANK3 Expression in PBMCs and Developing Cortical Interneurons in Schizophrenia

Schizophrenia (SCZ) is a severe psychiatric and neurodevelopmental disorder. The pathological process of SCZ starts early during development, way before the first onset of psychotic symptoms. DNA methylation plays an important role in regulating gene expression and dysregulated DNA methylation is involved in the pathogenesis of various diseases. The methylated DNA immunoprecipitation-chip (MeDIP-chip) is performed to investigate genome-wide DNA methylation dysregulation in peripheral blood mononuclear cells (PBMCs) of patients with first-episode SCZ (FES). Results show that the SHANK3 promoter is hypermethylated, and this hypermethylation (HyperM) is negatively correlated with the cortical surface area in the left inferior temporal cortex and positively correlated with the negative symptom subscores in FES. The transcription factor YBX1 is further found to bind to the HyperM region of SHANK3 promoter in induced pluripotent stem cells (iPSCs)-derived cortical interneurons (cINs) but not glutamatergic neurons. Furthermore, a direct and positive regulatory effect of YBX1 on the expression of SHANK3 is confirmed in cINs using shRNAs. In summary, the dysregulated SHANK3 expression in cINs suggests the potential role of DNA methylation in the neuropathological mechanism underlying SCZ. The results also suggest that HyperM of SHANK3 in PBMCs can serve as a potential peripheral biomarker of SCZ.

Negative symptoms in the clinic: we treat what we can describe

Recent research has led to important changes in the concepts and assessment of negative symptoms in schizophrenia. We review current negative symptom concepts and their clinical implications, as well as new methods of assessing these symptoms. These changes hold promise for improving our understanding and treatment of negative symptoms.

A transdiagnostic approach to negative symptoms: exploring factor structure and negative symptoms in bipolar disorders

Background

Negative symptoms are increasingly recognized as transdiagnostic phenomena, linked to reduced quality of life and functioning, and often caused or worsened by amendable external factors such as depression, social deprivation, side-effects of antipsychotics or substance use. The structure of negative symptoms fits into two dimensions: diminished expression and apathy. These may differ in association with external factors that influence their severity and may thus require different treatment approaches. The dimensions are comprehensively established in non-affective psychotic disorders but are understudied in bipolar disorders.

Methods

We conducted exploratory and confirmatory factor analyses in a sample of 584 individuals with bipolar disorder to assess the latent factor structure of negative symptoms as measured by the Positive and Negative Syndrome Scale (PANSS), and performed correlational analyses and multiple hierarchical regression analyses to investigate links between the two dimensions of negative symptoms and clinical and sociodemographic correlates.

Results

The latent factor structure of negative symptoms fits into two dimensions, i.e., diminished expression and apathy. A diagnosis of bipolar type I or a history of psychotic episodes predicted more severe levels of diminished expression. Depressive symptoms were associated with more severe negative symptoms across dimensions, yet 26.3% of euthymic individuals still displayed at least one mild or more severe negative symptom (PANSS score ≥ 3).

Discussion

The two-dimensional structure of negative symptoms seen in non-affective psychotic disorders reproduces in bipolar disorders indicating similarities in their phenomenology. Diminished expression was associated with a history of psychotic episodes and a diagnosis of BD-I, which may infer closer connections to psychosis liability. We found significantly less severe negative symptoms in euthymic than depressed participants. Nevertheless, more than a quarter of the euthymic individuals had at least one mild negative symptom, demonstrating some degree of persistence beyond depressed states.

The European Portuguese Version of the Brief Negative Symptom Scale

Negative symptoms reflect a currently much-untreated loss of normal functioning and are frequently found in psychotic disorders. We present the first translation of the Brief Negative Symptom Scale (BNSS) to European Portuguese and evaluate its validity in a sample of Portuguese male patients with a psychotic spectrum disorder. The Portuguese BNSS showed excellent internal consistency, high convergent validity (i.e., strong correlation with the PANSS negative factor), and high discriminant validity (i.e., a lack of association with the PANSS positive factor). In sum, the present European Portuguese BNSS has shown to be reliable, thus extending this instrument's clinical availability worldwide.

Effort-Cost Decision-making Among Individuals With Schizophrenia: A Systematic Review and Meta-analysis

Importance

Motivational impairments in schizophrenia are by definition associated with poor outcome. It is postulated that the reduction of goal-directed behavior arises from abnormal trade-offs between rewards and efforts.

Objective

To examine whether schizophrenia is associated with impairments in effort-cost decision-making.

Data Sources

For this systematic review and meta-analysis, the PubMed, ScienceDirect, PsycINFO, Embase, and ClinicalTrials.gov databases were searched from inception to July 2022 for studies that investigated effort-cost decision-making in schizophrenia. Search terms included effort, cost, and schizophrenia.

Study Selection

Consensual criteria for inclusion were peer-reviewed studies published in English that used a computerized effort-cost decision-making behavioral paradigm and compared individuals with schizophrenia with control individuals.

Data Extraction and Synthesis

The Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline was used for abstracting data. Data were extracted independently by 2 authors and then pooled using random-effects sizes and bayesian approaches.

Main Outcomes and Measures

The main outcomes were performance on effort-cost decision-making tasks requiring an effort-reward trade-off, measured by Hedges g effect size. Effects of moderators were tested with meta-regressions and subgroup analyses.

Results

Twenty studies involving 1503 participants were included: 837 individuals with schizophrenia (541 [64.6%] male; mean [SD] age, 35.89 [6.70] years) and 666 control individuals without schizophrenia (360 [54.1%] male; mean [SD] age, 34.16 [5.92] years). Participants with schizophrenia had significantly reduced willingness to expend effort for rewards compared with controls (k = 20; effect size, 0.43; 95% CI, 0.30-0.56; P < .001; I2 = 33.1%; Q test P = .08). The magnitude of the deficit was significantly greater for high-reward trials. The severity of negative symptoms was negatively associated with effort-cost decision-making (k = 8; effect size, -0.33; 95% CI, -0.50 to -0.15; P < .001), while participants with a high number of negative symptoms had a significantly larger impairment in effort-cost decision-making (k = 5; effect size, 0.47; 95% CI, 0.10-0.84; P = .01).

Conclusions and Relevance

In this systematic review and meta-analysis, schizophrenia was associated with deficits in effort allocation as indexed by effort-cost decision-making tasks. Understanding the cognitive and neurobiological mechanisms driving effort allocation impairments may assist in developing novel interventions.

Negative symptoms in First-Episode Schizophrenia related to morphometric alterations in orbitofrontal and superior temporal cortex: the OPTiMiSE study

BACKGROUND

Negative symptoms are one of the most incapacitating features of Schizophrenia but their pathophysiology remains unclear. They have been linked to alterations in grey matter in several brain regions, but findings have been inconsistent. This may reflect the investigation of relatively small patient samples, and the confounding effects of chronic illness and exposure to antipsychotic medication. We sought to address these issues by investigating concurrently grey matter volumes (GMV) and cortical thickness (CTh) in a large sample of antipsychotic-naïve or minimally treated patients with First-Episode Schizophrenia (FES).

METHODS

T1-weighted structural MRI brain scans were acquired from 180 antipsychotic-naïve or minimally treated patients recruited as part of the OPTiMiSE study. The sample was stratified into subgroups with (N = 88) or without (N = 92) Prominent Negative Symptoms (PMN), based on PANSS ratings at presentation. Regional GMV and CTh in the two groups were compared using Voxel-Based Morphometry (VBM) and FreeSurfer (FS). Between-group differences were corrected for multiple comparisons via Family-Wise Error (FWE) and Monte Carlo z-field simulation respectively at p < 0.05 (2-tailed).

RESULTS

The presence of PMN symptoms was associated with larger left inferior orbitofrontal volume (p = 0.03) and greater CTh in the left lateral orbitofrontal gyrus (p = 0.007), but reduced CTh in the left superior temporal gyrus (p = 0.009).

CONCLUSIONS

The findings highlight the role of orbitofrontal and temporal cortices in the pathogenesis of negative symptoms of Schizophrenia. As they were evident in generally untreated FEP patients, the results are unlikely to be related to effects of previous treatment or illness chronicity.

Negative Symptom Inventory-Self-Report (NSI-SR): Initial development and validation

Negative symptoms (i.e., anhedonia, avolition, asociality, blunted affect, alogia) are frequently observed in the schizophrenia-spectrum (SZ) and associated with functional disability. While semi-structured interviews of negative symptoms represent a gold-standard approach, they require specialized training and may be vulnerable to rater biases. Thus, brief self-report questionnaires measuring negative symptoms may be useful. Existing negative symptom questionnaires demonstrate that this approach may be promising in schizophrenia, but no measure has been devised for use across stages of psychotic illness. The present study reports initial psychometric validation of the Negative Symptom Inventory-Self-Report (NSI-SR), the self-report counterpart of the Negative Symptom Inventory-Psychosis Risk clinical interview. The NSI-SR is a novel transphasic negative symptoms measure assessing the domains of anhedonia, avolition, and asociality. The NSI-SR and related measures were administered to two samples: 1) undergraduates (n = 335), 2) community participants, including: SZ (n = 32), clinical-high risk for psychosis (CHR, n = 25), and healthy controls matched to SZ (n = 31) and CHR (n = 30). The psychometrically trimmed 11-item NSI-SR showed good internal consistency and a three-factor solution reflecting avolition, asociality, and anhedonia. The NSI-SR demonstrated convergent validity via moderate to large correlations with clinician-rated negative symptoms and related constructs in both samples. Discriminant validity was supported by lower correlations with positive symptoms in both samples; however, correlations with positive symptoms were still significant. These initial psychometric findings suggest that the NSI-SR is a reliable and valid brief questionnaire capable of measuring negative symptoms across phases of psychotic illness.

The impact of early factors on persistent negative symptoms in youth at clinical high risk for psychosis

Introduction

Persistent negative symptoms (PNS) are described as continuing moderate negative symptoms. More severe negative symptoms have been associated with poor premorbid functioning in both chronic schizophrenia and first episode psychosis patients. Furthermore, youth at clinical high risk (CHR) for developing psychosis may also present with negative symptoms and poor premorbid functioning. The aim of this current study was to: (1) define the relationship between PNS and premorbid functioning, life events, trauma and bullying, previous cannabis use, and resource utilization, and (2) to examine what explanatory variables best predicted PNS.

Method

CHR participants (N = 709) were recruited from the North American Prodrome Longitudinal Study (NAPLS 2). Participants were divided into two groups: those with PNS (n = 67) versus those without PNS (n = 673). A K-means cluster analysis was conducted to distinguish patterns of premorbid functioning across the different developmental stages. The relationships between premorbid adjustment and other variables were examined using independent samples t-tests or chi square for categorical variables.

Results

There was significantly more males in the PNS group. Participants with PNS had significantly lower levels of premorbid adjustment in childhood, early adolescence, and late adolescence, compared to CHR participants without PNS. There were no differences between the groups in terms of trauma, bullying, and resource utilization. The non-PNS group had more cannabis use and more desirable and non-desirable life events.

Conclusion

In terms of better understanding relationships between early factors and PNS, a prominent factor associated with PNS was premorbid functioning, in particular poor premorbid functioning in later adolescence.

"Goals in Focus"-a targeted CBT approach for motivational negative symptoms of psychosis: study protocol for a randomized-controlled feasibility trial

BACKGROUND

The reduction of goal-directed behavior is the main characteristic in motivational negative symptoms of psychosis as it accounts for the long-term decline in psychological well-being and psychosocial functioning. However, the available treatment options are largely unspecific and show only small effects on motivational negative symptoms. Interventions that directly target the relevant psychological mechanisms are likely to be more effective. For "Goals in Focus", we translated findings from basic clinical research on mechanisms underlying motivational negative symptoms into a tailored and comprehensive novel psychological outpatient treatment program. With this study, we will test the feasibility of the therapy manual and the trial procedures. We also aim to examine first estimates of the effect size that can be expected from "Goals in Focus" to inform the sample size calculation of a subsequent fully powered trial.

METHODS

Thirty participants diagnosed with a schizophrenia spectrum disorder and at least moderate motivational negative symptoms will be randomly assigned to either 24 sessions of "Goals in Focus" over the course of 6 months (n = 15) or to a 6-month wait-list control group (n = 15). Single-blind assessments will be conducted at baseline (t₀) and 6 months after baseline completion (t₁). Feasibility outcomes include patient recruitment, retention, and attendance rates. Acceptability will be rated by trial therapists and by participants at end of treatment. Primary outcome for effect size estimation is the motivational negative symptom subscale sum score of the Brief Negative Symptom Scale at t₁ corrected for baseline values. Secondary outcomes include psychosocial functioning, psychological well-being, depressive symptoms, expressive negative symptoms, negative symptom factor scores, and goal pursuit in everyday life.

DISCUSSION

The feasibility and acceptability data will be used to improve trial procedures and the "Goals in Focus" intervention where necessary. The treatment effect on the primary outcome will provide the basis for the sample size calculation for a fully powered RCT.

TRIAL REGISTRATION

1) ClinicalTrials.gov, NCT05252039 . Registered on 23 February 2022. 2) Deutsches Register Klinischer Studien, DRKS00018083 . Registered on 28 August 2019.

The motivation and pleasure deficits but not expressivity affects social functioning through cognitive function in male patients with schizophrenia: A structural equation model

OBJECTIVE

This study aims to compare cognitive function and social functioning in male schizophrenia patients with deficit syndrome (DS) and non-DS, and to explore the associations among two different dimensions of negative symptoms (motivation and pleasure (MAP) and expressivity (EXP) deficits), cognitive function and social functioning base on a Structural Equation Model (SEM).

METHODS

The current study enrolled 161 male schizophrenia patients and 120 age- and education- matched healthy controls. The DS and non-DS group were categorized by the Chinese version of Schedule for the Deficit Syndrome (SDS). The psychotic and negative symptoms were evaluated by the Brief Psychiatric Rating Scale (BPRS) and the Brief Negative Symptoms Scale (BNSS). The Social functioning was measured by Scale of Social function in Psychosis Inpatients (SSPI). A battery of classical neurocognitive tests was used for assessing cognition including sustained vigilance/attention, cognitive flexibility, ideation fluency and visuospatial memory.

RESULTS

Our study indicated that DS patients performed worser in cognitive function and social functioning than non-DS patients. The SEM model demonstrated that MAP significantly affected social functioning through direct influence and mediation of cognitive function. However, our results found that EXP had little influence on cognitive function and social function.

CONCLUSION

Our findings provided evidence supporting that DS may represent as a subtype of schizophrenia, and the MAP factor play a pivotal role to influence the cognitive and social functioning in schizophrenia patients.