Psychometric evaluation of the negative syndrome of schizophrenia

The dimensional structure of the Positive and Negative Syndrome Scale in first-episode schizophrenia spectrum disorders: an Exploratory Graph Analysis from the OPTiMiSE trial

The Positive and Negative Syndrome Scale (PANSS) is the most widely used rating scale to assess psychotic symptoms in patients with schizophrenia and other primary psychoses. However, a definitive consensus regarding its dimensional structure remains elusive. The present work aims to determine the number of dimensions of the scale through a network analysis approach in a sample of individuals experiencing first-episode schizophrenia spectrum disorder (FE-SSD) with minimal or no prior exposure to antipsychotic treatment. Baseline data of 446 participants (age 25.96 ± 5.99 years, 70% males) enrolled in the OPTiMiSE trial were analysed. Exploratory Graph Analysis (EGA) was conducted to evaluate the dimensionality of the PANSS, and a bootstrap approach (bootEGA) was employed to assess model stability. The analysis was replicated, excluding unstable items with stability values below 0.75, until a stable model was achieved. The analysis of the 30 items of the PANSS revealed inadequate structural consistency, resulting in the exclusion of 9 unstable items. The final model comprised 21 symptoms distributed across four communities (Positive, Cognitive/Disorganised, Excited/Aggressive and Negative) but lacked a depressive domain. In conclusion, we propose a concise version of the PANSS, incorporating 21 items, to better assess the core symptoms of the first episode of SSD. This revised version provides clinicians with a robust psychometric tool with reduced administration time, but the complementary administration of a dedicated instrument for evaluating affective symptoms is advisable.

The Impact of Childhood Trauma on the Negative Symptoms of Schizophrenia

ABSTRACT

Schizophrenia is a debilitating mental health disorder that imposes profound economic, societal, and personal burdens. The negative symptoms of schizophrenia ( i.e. , blunted affect, alogia, anhedonia, asociality, and avolition) are highly prevalent and pervasive in the psychotic disorder and pose significant resistance to available treatment options. Traumatic childhood experiences are strongly linked with the risk of developing schizophrenia. Most prior studies have primarily focused on positive symptoms of schizophrenia ( e.g. , hallucinations and delusions), whereas less attention has been given to negative symptoms. The current study investigated the relationship between childhood trauma ( i.e. , physical abuse, sexual abuse, and emotional abuse and neglect) and negative symptoms in a sample of schizophrenia outpatients and healthy controls ( n = 159 participants, including 99 patients with schizophrenia). The observations from the current study revealed that schizophrenia patients experienced a significantly greater degree of childhood trauma and negative symptoms than the control individuals. The results of the current study also indicated that more severe experiences of total childhood trauma ( i.e. , summation of all trauma types), physical abuse, and emotional neglect may increase the risk of schizophrenia patients reporting negative symptoms. However, childhood sexual and emotional abuse was found to have no impact on the degree of negative symptoms experienced by schizophrenia patients. Implications and limitations of the current study are discussed. In conclusion, we found that the severity of overall childhood trauma, physical abuse, and emotional neglect may play an important role in increasing the likelihood of schizophrenia patients reporting negative symptoms.

Intermittent Theta Burst Stimulation Combined with Cognitive Training to Improve Negative Symptoms and Cognitive Impairment in Schizophrenia: A Pilot Study

Schizophrenia is a chronic psychiatric disorder severely affecting patients' functioning and quality of life. Unlike positive symptoms, cognitive impairment and negative symptoms cannot be treated pharmacologically and represent consistent predictors of the illness's prognosis. Cognitive remediation (CR) interventions have been applied to target these symptoms. Brain stimulation also provides promising yet preliminary results in reducing negative symptoms, whereas its effect on cognitive impairment remains heterogeneous. Here, we combined intermittent theta burst stimulation (iTBS) with CR to improve negative symptoms and cognitive impairment in schizophrenia spectrum patients. One hundred eligible patients were invited, and twenty-one participated. We randomized them into four groups, manipulating the stimulation condition (real vs. sham) and CR (no training vs. training). We delivered fifteen iTBS sessions over the left dorsolateral prefrontal cortex for three weeks, followed (or not) by 50 min of training. Consensus-based clinical and cognitive assessment was administered at baseline and after the treatment, plus at three follow-ups occurring one, three, and six months after the intervention. Mixed-model analyses were run on cognitive and negative symptom scores. The preliminary findings highlighted a marginal modulation of iTBS on negative symptoms, whereas CR improved isolated cognitive functions. We herein discuss the limitations and strengths of the methodological approach.

Correlation of Health-Related Quality of Life with Negative Symptoms Assessed with the Self-Evaluation of Negative Symptoms Scale (SNS) and Cognitive Deficits in Schizophrenia: A Cross-Sectional Study in Routine Psychiatric Care

(1) Background: Schizophrenia is a severe mental disorder characterized by various symptom groups that tremendously affect health-related quality of life (HRQoL). We aimed to specify whether negative symptoms and cognitive deficits of schizophrenia correlate and can predict HRQoL. (2) Methods: Patients diagnosed with paranoid schizophrenia were invited to participate in the study. Participants were evaluated using the Montreal Cognitive Assessment (MoCA) and the Brief Psychiatric Rating Scale (BPRS) and were asked to fill out the Self-evaluation of Negative Symptoms scale (SNS) and the Medical Outcomes Short Form Survey (SF-36). Pearson's and Spearman's correlations were used to calculate the correlations between cognitive deficits and negative symptoms. We performed the receiver operating characteristic (ROC) analysis for the variables correlated with SF-36 scores. (3) Results: HRQoL correlated significantly with the negative symptoms; however, it did not correlate with cognitive deficits. ROC analysis showed that the abulia subscore of the SNS showed the most significant predictive potential of HRQoL. (4) Conclusions: Negative symptoms correlate more significantly with the HRQoL than cognitive symptoms. The SNS offers the possibility of predicting the HRQoL of patients with schizophrenia and is useful as a screening tool in clinical practice.

Validation of accelerometry as a digital phenotyping measure of negative symptoms in schizophrenia

Negative symptoms are commonly assessed via clinical rating scales; however, these measures have several inherent limitations that impact validity and utility for their use in clinical trials. Objective digital phenotyping measures that overcome some of these limitations are now available. The current study evaluated the validity of accelerometry (ACL), a passive digital phenotyping method that involves collecting data on the presence, vigor, and variability of movement. Outpatients with schizophrenia (SZ: n = 50) and demographically matched healthy controls (CN: n = 70) had ACL continuously recorded from a smartphone and smartband for 6 days. Active digital phenotyping assessments, including surveys related to activity context, were also collected via 8 daily surveys throughout the 6 day period. SZ participants had lower scores on phone ACL variables reflecting vigor and variability of movement compared to CN. ACL variables demonstrated convergent validity as indicated by significant correlations with active digital phenotyping self-reports of time spent in goal-directed activities and clinical ratings of negative symptoms. The discriminant validity of ACL was demonstrated by low correlations with clinical rating scale measures of positive, disorganized, and total symptoms. Collectively, findings suggest that ACL is a valid objective measure of negative symptoms that may complement traditional approaches to assessing the construct using clinical rating scales.

Mechanisms Underlying Motivational Dysfunction in Schizophrenia

Negative symptoms are a debilitating feature of schizophrenia which are often resistant to pharmacological intervention. The mechanisms underlying them remain poorly understood, and diagnostic methods rely on phenotyping through validated questionnaires. Deeper endo-phenotyping is likely to be necessary in order to improve current understanding. In the last decade, valuable behavioural insights have been gained through the use of effort-based decision making (EBDM) tasks. These have highlighted impairments in reward-related processing in schizophrenia, particularly associated with negative symptom severity. Neuroimaging investigations have related these changes to dysfunction within specific brain networks including the ventral striatum (VS) and frontal brain regions. Here, we review the behavioural and neural evidence associated with negative symptoms, shedding light on potential underlying mechanisms and future therapeutic possibilities. Findings in the literature suggest that schizophrenia is characterised by impaired reward based learning and action selection, despite preserved hedonic responses. Associations between amotivation and reward-processing deficits have not always been clear, and may be mediated by factors including cognitive dysfunction or dysfunctional or self-defeatist beliefs. Successful endo-phenotyping of negative symptoms as a function of objective behavioural and neural measurements is crucial in advancing our understanding of this complex syndrome. Additionally, transdiagnostic research–leveraging findings from other brain disorders, including neurological ones–can shed valuable light on the possible common origins of motivation disorders across diseases and has important implications for future treatment development.

Validation of the lithuanian version of the self-evaluation of negative symptoms scale (SNS)

PURPOSE

To validate the Lithuanian version of the Self-Evaluation Negative Symptoms Scale (Lith-SNS).

MATERIALS AND METHODS

A double translation from French to Lithuanian and back was performed. We included patients from in-patient and out-patient settings that had a diagnosis of paranoid schizophrenia according to ICD-10 criteria and were screened as free from acute psychotic symptoms using the Mini International Neuropsychiatric Interview (MINI). Participants were evaluated using the Brief Psychiatric Rating Scale (BRPS) and completed the Lith-SNS scale. We measured internal consistency, convergent validity, and discriminant validity of Lith - SNS comparing its scores with BPRS negative and positive symptom subscores.

RESULTS

A total of 67 participants were evaluated. Cronbach's alpha (α) for all 20 items of Lith-SNS (α = 0.82), and for the five subscores (α = 0.76) showed good internal consistency. Factor analysis showed a 2-factor solution which accounted for 70.12% of the variance with the first factor accounting for 53.3% and the second factor accounting for 16.8% of the variance. Lith-SNS total scores and all five subscores significantly correlated with BPRS negative symptoms subscores showing good convergent validity. There was a correlation between the Positive subscore of BPRS and the alogia subscore of Lith-SNS (r = 0.39, p = 0.001), but no correlations with other subscores or the total Lith-SNS score showing adequate discriminant validity.

CONCLUSIONS

Lithuanian version of SNS is a valuable tool to evaluate negative symptoms of schizophrenia with good internal consistency, convergent, and discriminant validity.

[History and current state of the problem of negative disorders (research of nosological period)]

Pioneers of nosology in psychiatry considered mental deficit as a basic disorder obligated to all clinical forms of illness, as did E. Kraepelin in the concept of dementia praecox and E. Bleuler in the concept of schizophrenia. At the present stage of studies, this position is clearly articulated in the «deficit schizophrenia» concept of J. Klosterkotter. Negative disorders are considered in categorical approach to interpret psychopathological dimensions of schizophrenia as coordinated, strongly bound with positive syndromes (concept of «dialectical unity» of A.V. Snezhnevskiy, 1964) and classified as syndromes according to systematics of positive disorders. However, distinguished types of negative disorders are determined in terms of positive syndromes or characterological changes (asthenic, pseudopsychopathic deficit). Within a new paradigm (dimensional approach to schizophrenia), which differs from the categorical approach, negative disorders are considered as a distinct domain, primary in relation to other psychopathological phenomena of schizophrenia). A concept of primary persistent negative symptoms serves as basis of the current concept of schizophrenic deficit. Factor analysis revealed two domains of negative disorders: 1) emotional blunting: blunted affect, alogia; 2) avolition: apathy, anhedonia, asociality.

EPA guidance on assessment of negative symptoms in schizophrenia

Background

During the last decades, a renewed interest for negative symptoms (NS) was brought about by the increased awareness that they interfere severely with real-life functioning, particularly when they are primary and persistent.

Methods

In this guidance paper, we provide a systematic review of the evidence and elaborate several recommendations for the conceptualization and assessment of NS in clinical trials and practice.

Results

Expert consensus and systematic reviews have provided guidance for the optimal assessment of primary and persistent negative symptoms; second-generation rating scales, which provide a better assessment of the experiential domains, are available; however, NS are still poorly assessed both in research and clinical settings.

This European Psychiatric Association (EPA) guidance recommends the use of persistent negative symptoms (PNS) construct in the context of clinical trials and highlights the need for further efforts to make the definition of PNS consistent across studies in order to exclude as much as possible secondary negative symptoms. We also encourage clinicians to use second-generation scales, at least to complement first-generation ones.

The EPA guidance further recommends the evidence-based exclusion of several items included in first-generation scales from any NS summary or factor score to improve NS measurement in research and clinical settings. Self-rated instruments are suggested to further complement observer-rated scales in NS assessment.

Several recommendations are provided for the identification of secondary negative symptoms in clinical settings.

Conclusions

The dissemination of this guidance paper may promote the development of national guidelines on negative symptom assessment and ultimately improve the care of people with schizophrenia.

On the relation of white matter brain abnormalities and the asociality symptoms in schizophrenia outpatients - a DTI study

Recent MRI studies have shown that abnormal functional connections in schizophrenia coexist with subtle changes in the structure of axons in the brain. However, there is a discrepancy in the literature concerning the relationship between white matter abnormalities and the occurrence of negative psychopathological symptoms. In the present study, we investigate the relationship between the altered white matter structure and specific psychopathology symptoms, i.e., subscales of Positive and Negative Syndrome Scale (PANSS) and Brief Negative Symptoms Scale (BNSS) in a sample of schizophrenia outpatients. For investigation on white matter abnormalities in schizophrenia, the diffusion tensor imaging analysis of between-group differences in main diffusion parameters by tract-based spatial statistics was conducted on schizophrenia outpatients and healthy controls. Hence, the correlation of PANSS and BNSS psychopathology subscales in the clinical group with fractional anisotropy was analyzed in the 17 selected cortical regions of interest. Presented between-group results revealed widespread loss of white matter integrity located across the brain in schizophrenia outpatients. Results on the white matter relationship with psychopathology revealed the negative correlation between fractional anisotropy in the left orbital prefrontal cortex, right Heschl's gyrus, bilateral precuneus and posterior cingulate cortex and the severity of asociality, as assessed with the BNSS. In conclusion, the presented study confirms the previous evidence on the widespread white matter abnormalities in schizophrenia outpatients and indicates the existence of the subtle but specific association between fractional anisotropy in the fronto-temporo-parietal regions with the asociality.

Recent MRI studies have shown that abnormal functional connections in schizophrenia coexist with subtle changes in the structure of axons in the brain. However, there is a discrepancy in the literature concerning the relationship between white matter abnormalities and the occurrence of negative psychopathological symptoms. In the present study, we investigate the relationship between the altered white matter structure and specific psychopathology symptoms, i.e., subscales of Positive and Negative Syndrome Scale (PANSS) and Brief Negative Symptoms Scale (BNSS) in a sample of schizophrenia outpatients. For investigation on white matter abnormalities in schizophrenia, the diffusion tensor imaging analysis of between-group differences in main diffusion parameters by tract-based spatial statistics was conducted on schizophrenia outpatients and healthy controls. Hence, the correlation of PANSS and BNSS psychopathology subscales in the clinical group with fractional anisotropy was analyzed in the 17 selected cortical regions of interest. Presented between-group results revealed widespread loss of white matter integrity located across the brain in schizophrenia outpatients. Results on the white matter relationship with psychopathology revealed the negative correlation between fractional anisotropy in the left orbital prefrontal cortex, right Heschl’s gyrus, bilateral precuneus and posterior cingulate cortex and the severity of asociality, as assessed with the BNSS. In conclusion, the presented study confirms the previous evidence on the widespread white matter abnormalities in schizophrenia outpatients and indicates the existence of the subtle but specific association between fractional anisotropy in the fronto-temporo-parietal regions with the asociality.

Improving Knowledge on Pathways to Functional Outcome in Schizophrenia: Main Results From the Italian Network for Research on Psychoses

The identification of factors associated with functional outcome of subjects with schizophrenia is a great challenge in current research oriented to the personalization of care. The Italian Network for Research on Psychoses (NIRP) is a network of 26 university psychiatric clinics and/or mental health departments aimed to carry out multicenter research projects to improve the standards of prevention, diagnosis, and treatments of schizophrenia. The network has promoted 2 main studies, a cross-sectional one and a longitudinal one and seven "add-on" studies. The cross-sectional study of the network included 921 subjects with schizophrenia, 379 unaffected first-degree relatives of these patients, and 780 healthy controls. Results from this study documented that social and non-social cognition, functional capacity, negative symptoms, resilience, and family or social incentives strongly influence a measure of global functioning. The follow-up study included 618 patients from the original sample and has produced evidence of the key role of cognition, functional capacity, the experiential domain of negative symptoms, and everyday life skills in predicting functional outcome. The longitudinal study demonstrated that social cognition and the experiential domain of negative symptoms had an impact on interpersonal functioning, while non-social cognition had an impact on everyday life skills. Both non-social cognition and social cognition predicted work skills. The research question concerning the relationships of cognitive impairment and negative symptoms has been investigated with an innovative approach, using a structural equation model (SEM) and a network analysis. Both analyses demonstrated that only the experiential domain of negative symptoms had a distinct direct effect on functioning. The network analysis showed that expressive deficit was connected to functional capacity, as were social and non-social cognitive variables, and to disorganization. These findings were confirmed by the follow-up study. The add-on studies showed distinct electrophysiological correlates of the two negative symptom domains and the partial overlap between disorganization and neurocognitive impairment. Moreover, they identified and characterized a specific subgroup of patients suffering from schizophrenia with autism spectrum symptoms. The NIRP studies have implications for personalized management of patients with schizophrenia and highlight the need for a careful assessment of several domains rarely evaluated in clinical settings.

Clinical, behavioural and neural validation of the PANSS amotivation factor

Negative symptoms in schizophrenia have been suggested to map onto two distinct factors - amotivation and diminished expression. Only recently, two-factor solutions for measuring negative symptoms have been proposed for the Positive and Negative Symptom Scale (PANSS), the most commonly used scale to assess the psychopathology of patients with schizophrenia. We aimed to validate the PANSS two-factor structure on a clinical, behavioural and neural level. For this multi-level validation, we reanalysed several datasets with patients for whom both the Brief Negative Symptom Assessment Scale (BNSS) and PANSS data were collected. We used a clinical dataset (n = 120) as well as behavioural data from an effort-based decision making task (n = 31) and functional neuroimaging data from a monetary incentive delay task (n = 41). Both tasks have previously been shown to be associated with BNSS amotivation. On the clinical level, the PANSS amotivation and diminished expression were highly correlated with their BNSS counterparts. On the behavioural level, we found that the PANSS amotivation factor but not the diminished expression factor specifically associated with willingness to invest effort to obtain a reward. On the neural level, PANSS amotivation was specifically related to reduced ventral striatal activation during reward anticipation. Our data confirm that the PANSS clearly allows distinguishing amotivation from diminished expression, as it relates selectively to specific aspects of behaviour and brain function. Our results will allow a re-analysis and sharing of existing datasets that used the PANSS to further substantiate the distinction between the two factors in neuroscientific studies and clinical trials.

Oxytocin Enhances an Amygdala Circuit Associated With Negative Symptoms in Schizophrenia: A Single-Dose, Placebo-Controlled, Crossover, Randomized Control Trial

Negative symptoms are core contributors to vocational and social deficits in schizophrenia (SZ). Available antipsychotic medications typically fail to reduce these symptoms. The neurohormone oxytocin (OT) is a promising treatment for negative symptoms, given its role in complex social behaviors mediated by the amygdala. In sample 1, we used a double-blind, placebo-controlled, crossover design to test the effects of a single dose of intranasal OT on amygdala resting-state functional connectivity (rsFC) in SZ (n = 22) and healthy controls (HC, n = 24) using a whole-brain corrected approach: we identified regions for which OT modulated SZ amygdala rsFC, assessed whether OT-modulated circuits were abnormal in SZ relative to HC on placebo, and evaluated whether connectivity on placebo and OT-induced connectivity changes correlated with baseline negative symptoms in SZ. Given our modest sample size, we used a second SZ (n = 183) and HC (n = 178) sample to replicate any symptom correlations. In sample 1, OT increased rsFC between the amygdala and left middle temporal gyrus, superior temporal sulcus, and angular gyrus (MTG/STS/AngG) in SZ compared to HC. Further, SZ had hypo-connectivity in this circuit compared to HC on placebo. More severe negative symptoms correlated with less amygdala-to-left-MTG/STS/AngG connectivity on placebo and with greater OT-induced connectivity increases. In sample 2, we replicated the correlation between amygdala-left-MTG/STS/AngG hypo-connectivity and negative symptoms, finding a specific association with expressive negative symptoms. These data suggest intranasal OT can normalize functional connectivity in an amygdala-to-left-MTG/STS/AngG circuit that contributes to negative symptoms in SZ.

Efficacy and Safety of Transcranial Direct Current Stimulation for Treating Negative Symptoms in Schizophrenia: A Randomized Clinical Trial

IMPORTANCE

Negative symptoms represent a substantial burden in schizophrenia. Although preliminary studies have suggested that transcranial direct current stimulation (tDCS) is effective for some clusters of symptoms, the clinical benefits for negative symptoms are unclear.

OBJECTIVE

To determine the efficacy and safety of tDCS vs sham as an add-on treatment for patients with schizophrenia and predominant negative symptoms.

DESIGN, SETTING, AND PARTICIPANTS

The double-blind Schizophrenia Treatment With Electric Transcranial Stimulation (STARTS) randomized clinical trial was conducted from September 2014 to March 2018 in 2 outpatient clinics in the state of São Paulo, Brazil. Patients with schizophrenia with stable negative and positive symptoms and a minimum score of 20 points in the negative symptoms subscale of the Positive and Negative Syndrome Scale (PANSS) were included.

INTERVENTIONS

Ten sessions of tDCS performed twice a day for 5 days or a sham procedure. The anode and the cathode were positioned over the left prefrontal cortex and the left temporoparietal junction, respectively.

MAIN OUTCOMES AND MEASURES

Change in the PANSS negative symptoms subscale score at week 6 was the primary outcome. Patients were followed-up for an additional 6 weeks.

RESULTS

Of the 100 included patients, 20 (20.0%) were female, and the mean (SD) age was 35.3 (9.3) years. A total of 95 patients (95.0%) finished the trial. In the intention-to-treat analysis, patients receiving active tDCS showed a significantly greater improvement in PANSS score compared with those receiving the sham procedure (difference, 2.65; 95% CI, 1.51-3.79; number needed to treat, 3.18; 95% CI, 2.12-6.99; P < .001). Response rates for negative symptoms (20% improvement or greater) were also higher in the active group (20 of 50 [40%]) vs the sham group (2 of 50 [4%]) (P < .001). These effects persisted at follow-up. Transcranial direct current stimulation was well tolerated, and adverse effects did not differ between groups, except for burning sensation over the scalp in the active group (43.8%) vs the sham group (14.3%) (P = .003).

CONCLUSIONS AND RELEVANCE

Transcranial direct current stimulation was effective and safe in ameliorating negative symptoms in patients with schizophrenia.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02535676.

Symptomatic and functional outcomes after treatment with paliperidone palmitate 3-month formulation for 52 weeks in patients with clinically stable schizophrenia

BACKGROUND

Paliperidone palmitate 3-monthly (PP3M) formulation is a long-acting, injectable antipsychotic treatment approved in many countries worldwide for the maintenance treatment of adult patients with schizophrenia. This single-arm, open-label, phase IIIb study evaluated the efficacy and safety of converting patients with schizophrenia stabilized with paliperidone palmitate 1-month (PP1M) to PP3M in a naturalistic clinical setting.

METHODS

After screening (days -7 to 1), patients were converted from PP1M (50-150 mg eq.) to PP3M (175-525 mg eq.), and entered a 52-week, flexible-dose PP3M treatment period. The primary efficacy endpoint was symptomatic remission (SR) (Andreasen criteria) at last observation carried forward (LOCF) endpoint.

RESULTS

Patients (n = 305) received PP3M, of whom 291 (95.4%) completed the study. Doses of PP3M remained stable during the 12-month treatment period, and changes in dose were uncommon. Overall, 56.8% of patients [95% confidence interval (CI): 51.0, 62.4] achieved SR, and 31.8% achieved both symptomatic and functional remission (Personal and Social Performance scale total score > 70) at LOCF endpoint. Secondary endpoint results were generally consistent with primary endpoint results. There were improvements in Positive and Negative Syndrome Scale total, subscale and Marder factor scores, and also Clinical Global Impression-Severity and -Change scores from baseline to LOCF endpoint. Carer burden was reduced, and the proportion of patients requiring hospitalization for psychiatric reasons decreased from 13.5% in the 12 months prior to baseline to 4.6% during the treatment period. No new safety signals were identified.

CONCLUSION

Results from this naturalistic study were similar to those observed in previous randomized clinical trials of PP3M and underline the importance of continuous maintenance treatment in patients with schizophrenia.

Validation of the Chinese Version of the 16-Item Negative Symptom Assessment

PURPOSE

The Negative Symptom Assessment-16 (NSA-16) is an instrument with significant validity and utility for assessing negative symptoms associated with schizophrenia. This study aimed to validate the Chinese version of the NSA-16.

PATIENTS AND METHODS

A total of 172 participants with schizophrenia were assessed with the NSA-16, Scale for Assessment of Negative Symptoms (SANS), Positive and Negative Syndrome Scale (PANSS), Calgary Depression Scale for Schizophrenia (CDSS) and Rating Scale for Extrapyramidal Side Effects (RSESE). The factor structure of the NSA-16 was evaluated via exploratory and confirmatory factor analysis. Cronbach's α and intraclass correlation coefficients were computed. Correlations were evaluated via Spearman correlation coefficient.

RESULTS

The original five-factor model of the NSA-16 did not fit our sample. Exploratory factor analysis followed by confirmatory factor analysis suggested a three-factor structure, consisting of communication, emotion and motivation, with 15 items. The NSA with 15 items was termed as the NSA-15. The NSA-15 showed excellent convergent validity by high correlations with the SANS and PANSS total and negative factor scores and good divergent validity by independence from the PANSS positive factor, CDSS and RSESE. The NSA-15 showed good internal consistency, interrater reliability and test-retest reliability.

CONCLUSION

The NSA-15 is best characterized by a three-factor structure and is valid for assessing negative symptoms of schizophrenia in Chinese individuals.

Monetary Incentives Increase Metacognitive Confidence in Source Memory Performance in Patients With Schizophrenia

BACKGROUND

Contemporary psychiatric research focuses its attention on the patient's dysfunction of metacognition in relation to the basic cognitive processes of mental activity. The current study investigated dysfunctional metacognition in relation to self-monitoring of memory in patients diagnosed with schizophrenia. Dysfunctions in metacognition were examined by focusing on two types of metacognitive measures: post-decision wagering (PDW) scale and confidence ratings (CR) scale (CR).

OBJECTIVES

The research employed an action-memory task that required patients with schizophrenia (N = 39) and healthy controls (N = 50) to evaluate their metacognition by categorizing self-monitoring actions (imagined vs. performed actions) either with PDW or CR. It was hypothesized that metacognition in self-monitoring activity in patients diagnosed with schizophrenia is improved by imaginary monetary incentives.

MATERIAL AND METHODS

To test this hypothesis, participants were asked to memorize actions either performed or imagined during the first phase of the experiment. The second phase was to identify previous actions as performed, imagined or new, and then to express confidence using two measures of metacognition (CR or PDW scales) that were randomly allocated to participants.

RESULTS

Our study showed reduced performance in the action memory task for patients with schizophrenia, although there were no group differences in confidence measures when assessing self-monitoring actions. In particular, irrespective of the diagnosis, no differences in confidence measures for correct responses were found in the case of the PDW and CR scales. We also observed that metacognitive judgements were more accurate for incorrect responses when both groups used monetary incentives to reveal their metacognition.

CONCLUSIONS

Our findings suggest that monetary incentives improve accuracy of metacognition among both patients and healthy controls. This accuracy-enhancing effect of monetary incentives on metacognition was possibly a result of motivational processes, including aversion to loss. The paper discusses the potential application of PDW in therapeutic metacognitive training for patients with schizophrenia.

Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS): An update (2014-2018)

A group of European experts reappraised the guidelines on the therapeutic efficacy of repetitive transcranial magnetic stimulation (rTMS) previously published in 2014 [Lefaucheur et al., Clin Neurophysiol 2014;125:2150-206]. These updated recommendations take into account all rTMS publications, including data prior to 2014, as well as currently reviewed literature until the end of 2018. Level A evidence (definite efficacy) was reached for: high-frequency (HF) rTMS of the primary motor cortex (M1) contralateral to the painful side for neuropathic pain; HF-rTMS of the left dorsolateral prefrontal cortex (DLPFC) using a figure-of-8 or a H1-coil for depression; low-frequency (LF) rTMS of contralesional M1 for hand motor recovery in the post-acute stage of stroke. Level B evidence (probable efficacy) was reached for: HF-rTMS of the left M1 or DLPFC for improving quality of life or pain, respectively, in fibromyalgia; HF-rTMS of bilateral M1 regions or the left DLPFC for improving motor impairment or depression, respectively, in Parkinson's disease; HF-rTMS of ipsilesional M1 for promoting motor recovery at the post-acute stage of stroke; intermittent theta burst stimulation targeted to the leg motor cortex for lower limb spasticity in multiple sclerosis; HF-rTMS of the right DLPFC in posttraumatic stress disorder; LF-rTMS of the right inferior frontal gyrus in chronic post-stroke non-fluent aphasia; LF-rTMS of the right DLPFC in depression; and bihemispheric stimulation of the DLPFC combining right-sided LF-rTMS (or continuous theta burst stimulation) and left-sided HF-rTMS (or intermittent theta burst stimulation) in depression. Level A/B evidence is not reached concerning efficacy of rTMS in any other condition. The current recommendations are based on the differences reached in therapeutic efficacy of real vs. sham rTMS protocols, replicated in a sufficient number of independent studies. This does not mean that the benefit produced by rTMS inevitably reaches a level of clinical relevance.

A large European, multicenter, multinational validation study of the Brief Negative Symptom Scale

Negative symptoms represent an unmet need of treatment in schizophrenia. Although a consensus exists on negative symptom construct, and second generation assessment instruments reflecting the consensus are available, studies still rely upon old assessment instruments, that do not reflect recent conceptualizations and might limit progress in the search for effective treatments. This is often the case in the European context, where one of the challenges encountered in designing large studies is the availability of validated instruments in the many languages of the continent. To address this challenge and promote sound research on negative symptoms in Europe, the ECNP Schizophrenia Network coordinated a large multicenter, multinational validation study of the Brief Negative Symptom Scale (BNSS). Clinically-stable subjects with schizophrenia (SCZ, N = 249) were recruited from 10 European Countries. Apart from BNSS, subjects were administered the Positive and Negative Syndrome Scale (PANSS) and standardized instruments for depression, extrapyramidal symptoms and psychosocial functioning. Results showed an excellent internal consistency, convergent and discriminant validity of BNSS and replicated a 5 factor-model. A larger number of subjects with predominant negative symptoms, i.e. the target population for clinical trials, was identified by using the BNSS compared to the PANSS. Regression analysis showed that BNSS-avolition, a key negative symptom poorly assessed by PANSS, explained 23.9% of psychosocial functioning, while no combination of the PANSS core negative symptoms showed the same impact on functioning. The study demonstrated that BNSS has substantial advantages with respect to PANSS for the identification of the avolition domain and subjects with predominant negative symptoms.

Integrated assessment of visual perception abnormalities in psychotic disorders and relationship with clinical characteristics

BACKGROUND

The visual system is recognized as an important site of pathology and dysfunction in schizophrenia. In this study, we evaluated different visual perceptual functions in patients with psychotic disorders using a potentially clinically applicable task battery and assessed their relationship with symptom severity in patients, and with schizotypal features in healthy participants.

METHODS

Five different areas of visual functioning were evaluated in patients with schizophrenia and schizoaffective disorder (n = 28) and healthy control subjects (n = 31) using a battery that included visuospatial working memory (VSWM), velocity discrimination (VD), contour integration, visual context processing, and backward masking tasks.

RESULTS

The patient group demonstrated significantly lower performance in VD, contour integration, and VSWM tasks. Performance did not differ between the two groups on the visual context processing task and did not differ across levels of interstimulus intervals in the backward masking task. Performances on VSWM, VD, and contour integration tasks were correlated with negative symptom severity but not with other symptom dimensions in the patient group. VSWM and VD performances were also correlated with negative sychizotypal features in healthy controls.

CONCLUSION

Taken together, these results demonstrate significant abnormalities in multiple visual processing tasks in patients with psychotic disorders, adding to the literature implicating visual abnormalities in these conditions. Furthermore, our results show that visual processing impairments are associated with the negative symptom dimension in patients as well as healthy individuals.

PARANOID SCHIZOPHRENIA NEGATIVE SYMPTOMS FEATURES IN CASE OF PRESENCE OF MUSICAL EAR

In our work, we propose one of the options for a prognostic criterion, which at the beginning of the disease can provide sufficient evidence to predict the form and severity of negative symptoms in schizophrenia. Aim. To investigate the influence of the presence of ear on music on the degree of severity of deficiency symptoms in paranoid schizophrenia. The study was conducted on the basis of the third clinical department of the Lviv Regional Clinical Psychiatric Hospital for the period of 2015. 40 patients with paranoid form of schizophrenia, aged 18 to 35, were examined, of which: group I – 20 patients with advanced ear on music (average age 28.60±1.01 years) and group II – 20 patients with no ear on music (average age 27.30±1.15 years). The main methods of studying the observation groups were: clinical-psychopathological, pathopsychological, and statistical. The pathopsychological study of the evaluation of negative symptoms was conducted using the "Qualitative Assessment Scale for Positivity, Negative and General Psychopathological Syndromes" (PANSS – Positive and Negative Syndrome Scale), namely, its PANSS-NS subscale. Comparison of the probability of the difference between the average indices of unrelated groups was carried out using the Mann-Whitney method, comparing the relative parameters of the distribution structure by the xi-square criterion. Analysis of the results of the study shows that in patients with developed ear on music, the level of deficiency symptoms of negative symptoms under the PANSS-NS subclass is 2.2 times lower (p <0.01) than in patients with no developed ear on music: 2.04±0.14 against 4.46±0.17 points, respectively. Comparing the key indicators of the PANSS-NS subscale in patients with paranoid schizophrenia with advanced ear on music, it was found that the manifestations of "Violations of abstract thinking" (N5 – 2.35±0.15 points), "Violation of spontaneity and smoothness in the conversation" (N6 – 2.30±0.15 points) and "Stereotyped thinking" (N7 – 2.20±0.16 points). All these negative symptoms were in patients with muscular earache with significantly lower scores: from lack of severity (1 point) to weakness (3 points). The lack of expressiveness (1 point) was most common in N4 "Passive-apathy social strangeness " - 35.00±10.67 % of patients, very weak severity (2 points) - for N1 "Blurred passion" - 75.00±9.68 % of patients (p <0.05 with the proportion of negative symptoms 1 and 3 points), weakness (3 points) - for N5 – 45.00±11.12 % of patients (p <0.05 with the proportion of negative symptoms 1 point ) The highest proportion (70.00±10.25 %, p <0.05 with a share of negative symptoms of 6 points) of patients with paranoid schizophrenia without ear on music had a high severity (5 points) of rigidity and stereotyping of thinking (N7). The obtained data prove the influence of the factor of the presence of ear on music on deficit syndrome, as well as on the forms and degree of severity of negative symptoms in paranoid schizophrenia.

Can interleukin-2 and interleukin-1β be specific biomarkers of negative symptoms in schizophrenia?

INTRODUCTION

Evidence suggests the existence of cytokine disturbances in patients with schizophrenia but their association with psychopathology is still unclear. The aim of the current study was to determine if pro-inflammatory cytokine levels (tumor necrosis factor-α, interleukin (IL)-6, IL-2, IL-1β, IL-1RA) are increased in stable outpatients compared with healthy subjects, and to analyze if they could be specific biomarkers of clinical dimensions in schizophrenia.

METHODS

We studied 73 stable outpatients with schizophrenia in their first 10 years of illness and 73 age- and sex-matched healthy controls. An accurate assessment of clinical dimensions (positive, negative, depressive, cognitive) was performed in patients.

RESULTS

Only IL-6 levels were significantly increased in patients after controlling for body mass index, waist circumference, smoking, and psychopharmacological treatment, compared with healthy subjects. After adjusting for several confounders, multiple linear regression models identified that Positive and Negative Syndrome Scale negative symptoms, general psychopathology, and global severity are predicted by IL-1β concentrations, while motivation and pleasure domain of Clinical Assessment Interview for Negative Symptoms and Personal and Social Performance global functioning scores are predicted by IL-2 levels. Cognitive performance, positive, and depressive symptom severity did not correlate with any cytokine.

CONCLUSIONS

Our findings suggested that IL-6 concentrations are elevated in stable patients with schizophrenia. Whereas IL-2 specifically marks severity of the motivation and pleasure domain of negative symptoms, IL-1β is not specific to this dimension as it also predicts severity of general and global symptomatology.

Blunted vocal affect and expression is not associated with schizophrenia: A computerized acoustic analysis of speech under ambiguous conditions

INTRODUCTION

Patients with schizophrenia are consistently rated by clinicians as having high levels of blunted vocal affect and alogia. However, objective technologies have often failed to substantiate these abnormalities. It could be the case that negative symptoms are context-dependent.

OBJECTIVES

The present study examined speech elicited under conditions demonstrated to exacerbate thought disorder.

METHODS

The Rorschach Test was administered to 36 outpatients with schizophrenia and 25 nonpatient controls. Replies to separate "perceptual" and "memory" phases were analyzed using validated acoustic analytic methods.

RESULTS

Compared to nonpatient controls, schizophrenia patients did not display abnormal speech expression on objective measure of blunted vocal affect or alogia. Moreover, clinical ratings of negative symptoms were not significantly correlated with objective measures.

CONCLUSIONS

These findings suggest that in patients with schizophrenia, vocal affect/alogia is generally unremarkable under ambiguous conditions. Clarifying the nature of blunted vocal affect and alogia, and how objective measures correspond to what clinicians attend to when making clinical ratings are important directions for future research.

Efficacy of high-frequency repetitive transcranial magnetic stimulation on PANSS factors in schizophrenia with predominant negative symptoms - Results from an exploratory re-analysis

Repetitive transcranial magnetic stimulation (rTMS) applied to the left frontal lobe is discussed to be a promising add-on treatment for negative symptoms in schizophrenia. The Positive and Negative Syndrome Scale (PANSS) has been used as outcome parameter in several previous rTMS trials, but studies focusing on PANSS factor analyses are lacking. For this purpose, we used the available PANSS data of the 'rTMS for the Treatment of Negative Symptoms in Schizophrenia' (RESIS) trial to calculate different literature-based PANSS factors and to re-evaluate the impact of rTMS on negative symptoms in this trial. In an exploratory re-analysis of published data from the RESIS study (Wobrock et al. 2015), we tested the impact of rTMS applied to the left dorsolateral prefrontal cortex on two PANSS factors for negative symptoms in psychotic disorders as well as on a PANSS five-factor consensus model intending to show that active rTMS treatment improves PANSS negative symptom subscores. In accordance to the original analysis, all PANSS factors showed an improvement over time in the active and, to a considerable extent, also in the sham rTMS group. However, comparing the data before and directly after the rTMS intervention, the PANSS excitement factor improved in the active rTMS group significantly more than in the sham group, but this finding did not persist if follow-up data were taken into account. These additional analyses extend the previously reported RESIS trial results showing unspecific improvements in the PANSS positive subscale in the active rTMS group. Our PANSS factor-based approach to investigate the impact of prefrontal rTMS on different negative symptom domains confirmed no overall beneficial effect of the active compared to sham rTMS.

Oxidative stress biomarkers and clinical dimensions in first 10 years of schizophrenia

INTRODUCTION

Several studies have described increased oxidative stress parameters in patients with schizophrenia. The objectives of the current study were to identify potential oxidative stress biomarkers in stable patients during first 10 years of schizophrenia and determine if they are associated with specific clinical dimensions.

MATERIAL AND METHODS

Seventy-three clinically stable outpatients with schizophrenia and 73 sex and age-matched healthy controls were recruited. Sociodemographic, clinical and biological data were collected at enrollment. Blood biomarkers included homocysteine, the percentage of hemolysis, lipid peroxidation subproducts, and as an antioxidant biomarker, catalase activity in erythrocytes.

RESULTS

Comparative analyses after controlling for smoking and metabolic syndrome evidenced a significant increase in catalase activity in patients. Also, lower lipid peroxidation levels showed an association with negative symptoms.

CONCLUSIONS

In conclusion, compensatory antioxidant mechanisms might be increased in stable patients with schizophrenia at early stages. Furthermore, there may be an inverse relationship between oxidative stress and negative dimension.

Spanish validation of the Negative Symptom Assessment-16 (NSA-16) in patients with schizophrenia

INTRODUCTION

Negative symptoms are prevalent in schizophrenia and associated with a poorer outcome. Validated newer psychometric instruments could contribute to better assessment and improved treatment of negative symptoms. The Negative Symptom Assessment-16 (NSA-16) has been shown to have strong psychometric properties, but there is a need for validation in non-English languages. This study aimed to examine the psychometric properties of a Spanish version of the NSA-16 (Sp-NSA-16).

MATERIAL AND METHOD

Observational, cross-sectional validation study in a sample of 123 outpatients with schizophrenia.

ASSESSMENTS

NSA-16, PANSS, HDRS, CGI-SCH and PSP.

RESULTS

The results indicate appropriate psychometric properties, high internal consistency (Cronbach's alpha=0.86), convergent validity (PANSS negative scale, PANSS Marder Negative Factor and CGI-negative symptoms r values between 0.81 and 0.94) and divergent validity (PANSS positive scale and the HDRS r values between 0.10 and 0.34). In addition, the NSA-16 also exhibited discriminant validity (ROC curve=0.97, 95% CI=0.94 to 1.00; 94.3% sensitivity and 83.3% specificity).

CONCLUSIONS

The Sp-NSA-16 is reliable and valid for measuring negative symptoms in patients with schizophrenia. This provides Spanish clinicians with a new tool for clinical practice and research. However, it is necessary to provide further information about its inter-rater reliability.

Transformed PANSS Factors Intended to Reduce Pseudospecificity Among Symptom Domains and Enhance Understanding of Symptom Change in Antipsychotic-Treated Patients With Schizophrenia

Positive and Negative Syndrome Scale (PANSS) total score is the standard primary efficacy measure in acute treatment studies of schizophrenia. However, PANSS factors that have been derived from factor analytic approaches over the past several decades have uncertain clinical and regulatory status as they are, to varying degrees, intercorrelated. As a consequence of cross-factor correlations, the apparent improvement in key clinical domains (eg, negative symptoms, disorganized thinking/behavior) may largely be attributable to improvement in a related clinical domain, such as positive symptoms, a problem often referred to as pseudospecificity. Here, we analyzed correlations among PANSS items, at baseline and change post-baseline, in a pooled sample of 5 placebo-controlled clinical trials (N = 1710 patients), using clustering and factor analysis to identify an uncorrelated PANSS score matrix (UPSM) that minimized the degree of correlation between each resulting transformed PANSS factor. The transformed PANSS factors corresponded well with discrete symptom domains described by prior factor analyses, but between-factor change-scores correlations were markedly lower. We then used the UPSM to transform PANSS in data from 4657 unique schizophrenia patients included in 12 additional lurasidone clinical trials. The results confirmed that transformed PANSS factors retained a high degree of specificity, thus validating that low between-factor correlations are a reliable property of the USPM when transforming PANSS data from a variety of clinical trial data sets. These results provide a more robust understanding of the structure of symptom change in schizophrenia and suggest a means to evaluate the specificity of antipsychotic treatment effects.

Validation of the Korean Version of the Clinical Assessment Interview for Negative Symptoms

OBJECTIVE

Clinical Assessment Interview for Negative Symptoms (CAINS) has recently been developed to improve measurement of negative symptoms in schizophrenia. We performed a multi-center study to validate the Korean version of the CAINS (CAINS-K) and explore potential cultural variation.

METHODS

One hundred eighty schizophrenia patients diverse in demographic and illness profile were recruited from four centers in Korea. Along with the CAINS-K, the Scale for the Assessment of Negative Symptoms (SANS), Brief Psychiatric Rating Scale (BPRS), Calgary Depression Scale for Schizophrenia (CDSS), a self-report measure of behavioral inhibition and activation (BIS/BAS) and neurocognitive tasks were administered to verify external validities.

RESULTS

The CAINS-K showed high internal-consistency (0.92) and inter-rater reliability (0.77). Exploratory Factor Analysis replicated a two-factor structure of the original scale including motivation/pleasure and expression deficits dimensions. Korean patients tended to report lower pleasure compared to American patients in the prior study. The CAINS-K showed an adequate convergent validity with the SANS, negative symptoms of the BPRS, and BAS. A divergent validity was supported as the CAINS-K showed zero or only weak correlations with other symptoms of the BPRS, depression from the CDSS, and neurocognitive tasks.

CONCLUSION

The CAINS-K demonstrated high internal consistency and adequate external validities, and is expected to promote studies on negative symptoms in Korean patients with schizophrenia.

Oxytocin effects in schizophrenia: Reconciling mixed findings and moving forward

Schizophrenia is a severe mental illness that causes major functional impairment. Current pharmacologic treatments are inadequate, particularly for addressing negative and cognitive symptoms of the disorder. Oxytocin, a neuropeptide known to moderate social behaviors, has been investigated as a potential therapeutic for schizophrenia in recent years. Results have been decidedly mixed, leading to controversy regarding oxytocin's utility. In this review, we outline several considerations for interpreting the extant literature and propose a focused agenda for future work that builds on the most compelling findings regarding oxytocin effects in schizophrenia to date. Specifically, we examine underlying causes of heterogeneity in randomized clinical trials (RCTs) conducted thus far and highlight the complexity of the human oxytocin system. We then review evidence of oxytocin's effects on specific deficits in schizophrenia, arguing for further study using objective, precise outcome measures in order to determine whether oxytocin has the potential to improve functional impairment in schizophrenia.

An Assessment of Five (PANSS, SAPS, SANS, NSA-16, CGI-SCH) commonly used Symptoms Rating Scales in Schizophrenia and Comparison to Newer Scales (CAINS, BNSS)

Scales measuring positive and negative symptoms in schizophrenia remain the primary mo Scales measuring positive and negative symptoms in schizophrenia remain the primary mode of assessing and diagnosing schizophrenia by clinicians and researchers. The scales are mainly used to monitor the severity of positive and negative symptoms and track treatment response in schizophrenics. Although these scales are widely used, quality as well as general utility of each scale varies. The quality is determined by the validity and reliability of the scales. The utility of the scale is determined by the time of administration and the settings for which the scales can be administered in research or clinical settings. There are relatively fewer articles on the utility of newer scales like CAINS (Clinical Assessment Interview for Negative Symptoms) and the BNSS (Brief Negative Symptom Scale) that compare them to the older scales PANSS (Positive and Negative Symptoms Scale), SAPS (Scale for the Assessment of Positive Symptoms) SANS (the Scale for the Assessment of Negative Symptoms), NSA-16 (Negative Symptom Assessment-16) and CGI-SCH (Clinical Global Impression Schizophrenia.

The older scales were developed more than 30 years ago. Since then, our understanding of negative symptoms has evolved and currently there are newer rating scales evaluating the validity of negative symptoms. The older scales do not incorporate the latest research on negative symptoms. CAINS and BNSS are attractive for both their reliability and their concise accessible format, however, a scale that is simpler, accessible, user-friendly, that incorporates a multidimensional model of schizophrenia, addresses the psychosocial and cognitive component has yet to be developed.

Categorizing and assessing negative symptoms

PURPOSE OF REVIEW

To provide a review on studies published in the last year relevant to the categorization and assessment of negative symptoms.

RECENT FINDINGS

Recent research supported the validity of the 'deficit/non-deficit schizophrenia' categorization. Few studies confirmed the validity of the category 'persistent negative symptoms', whereas no recent study explored the validity of the category 'predominant negative symptoms'. The two-factor structure of the negative dimension is supported by studies reporting different correlates for the two subdomains: diminished expression and avolition/apathy. The need to further split avolition/apathy in two distinct components, that is anhedonia and amotivation, is confirmed in recent papers. Additional approaches to the assessment of negative symptoms have been proposed, including the self-assessment of negative symptoms, and the evaluation of negative symptoms in daily life and their assessment by means of computerized analyses.

SUMMARY

Negative symptoms represent an unmet need in the care of schizophrenia, as they are associated to poor response to available treatments and to poor functional outcome. Their accurate categorization and assessment represent a major challenge for research on neurobiological substrates and new treatment strategies.

Attention and memory bias to facial emotions underlying negative symptoms of schizophrenia

INTRODUCTION

This study assessed bias in selective attention to facial emotions in negative symptoms of schizophrenia and its influence on subsequent memory for facial emotions.

METHODS

Thirty people with schizophrenia who had high and low levels of negative symptoms (n = 15, respectively) and 21 healthy controls completed a visual probe detection task investigating selective attention bias (happy, sad, and angry faces randomly presented for 50, 500, or 1000 ms). A yes/no incidental facial memory task was then completed. Attention bias scores and recognition errors were calculated.

RESULTS

Those with high negative symptoms exhibited reduced attention to emotional faces relative to neutral faces; those with low negative symptoms showed the opposite pattern when faces were presented for 500 ms regardless of the valence. Compared to healthy controls, those with high negative symptoms made more errors for happy faces in the memory task. Reduced attention to emotional faces in the probe detection task was significantly associated with less pleasure and motivation and more recognition errors for happy faces in schizophrenia group only.

CONCLUSIONS

Attention bias away from emotional information relatively early in the attentional process and associated diminished positive memory may relate to pathological mechanisms for negative symptoms.

Psychometric properties of a Spanish-version of the Schizophrenia Objective Functioning Instrument (Sp-SOFI)

The Schizophrenia Objective Functioning Instrument (SOFI) is an interviewer-administered scale designed to objectively assess the actual level of patient functioning and to measure community functioning related to cognitive impairment and psychopathology. The aim was to examine the psychometric properties of the Spanish version of the SOFI (Sp-SOFI) in a sample of 155 Spanish outpatients with schizophrenia disorder. The instruments applied were Sp-SOFI, Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression-Schizophrenia Scale (CGI-SCH), Personal and Social Performance Scale (PSP), and Global Assessment of Functioning (GAF). The discrimination indexes of the Sp-SOFI items range from .21 to .77. Exploratory factor analysis showed an essentially one-dimensional structure. Cronbach's alpha was .93. Test-retest reliability for the Sp-SOFI total score was .87 (p < .001). The canonical correlation between SP-SOFI domains and PSP dimensions was .83. The multiple correlation coefficient between Sp-SOFI domains and GAF score was .84. Sp-SOFI scores were significantly different between high and low scores on the PANSS scales (p < .001). Sp-SOFI measures discriminated among patients with doubtful, mild, moderate, and severe schizophrenia disorder according to CGI-SCH scales (p < .001). New evidence about the validity of the SOFI was provided. The Sp-SOFI is a reliable and valid tool for using in clinical practice.

Pharmacological treatment of negative symptoms in schizophrenia

Effective treatment of negative symptoms is one of the most important unmet needs in schizophrenic disorders. Because the evidence on current psychopharmacological treatments is unclear, the authors reviewed the findings published to date by searching PubMed with the keywords negative symptoms, antipsychotics, antidepressants, glutamatergic compounds, monotherapy and add-on therapy and identifying additional articles in the reference lists of the resulting publications. The findings presented here predominantly focus on results of meta-analyses. Evidence for efficacy of current psychopharmacological medications is difficult to assess because of methodological problems and inconsistent results. In general, the second-generation antipsychotics (SGAs) do not appear to have good efficacy in negative symptoms, although some show better efficacy than first-generation antipsychotics, some of which also demonstrated efficacy in negative symptoms. Specific trials on predominant persistent negative symptoms are rare and have been performed with only a few SGAs. More often, trials on somewhat persistent negative symptoms evaluate add-on strategies to ongoing antipsychotic treatment. Such trials, mostly on modern antidepressants, have demonstrated some efficacy. Several trials with small samples have evaluated add-on treatment with glutamatergic compounds, such as the naturally occurring amino acids glycine and D-serine and new pharmacological compounds. The results are highly inconsistent, although overall efficacy results appear to be positive. The unsatisfactory and inconsistent results can be partially explained by methodological problems. These problems need to be solved in the future, and the authors propose some possible solutions. Further research is required to identify effective treatment for the negative symptoms of schizophrenia.