Validation of the Spanish version of the Clinical Assessment for Negative Symptoms (CAINS)

Sex differences in prolactin levels and clinical outcomes in patients with a first psychotic episode

AIM

To analyze the clinical, neurocognitive, and functional impact of prolactin levels according to sex in patients with a First Episode Psychosis (FEP).

METHODS

We measured prolactin levels in 221 non-affective FEP patients treated with antipsychotics (AP) and 224 healthy controls, at baseline and 2-year follow-up. We examined whether the relationships between clinical and functional variables were mediated by prolactin, controlling for antipsychotic use, according to sex.

RESULTS

Prolactin levels were higher in patients when compared to controls at both time points. Baseline factors associated with prolactin were chlorpromazine equivalents, attention, and executive functioning. In the FEP group, prolactin levels were associated with functioning and diminished expression in males, and with working memory in females. Prolactin levels (p=0.0134) played a role as a mediator between negative symptomatology (p=0.086) and functional outcome (p=0.008) only in FEP male patients at baseline.

CONCLUSIONS

Prolactin plays a role in the functionality and clinical symptomatology of FEP patients. Our results suggest that pharmacological counselling in patients with hyperprolactinemia at baseline and negative symptomatology might improve their functional and clinical outcomes.

Anticholinergic load: A commonly neglected and preventable risk to cognition during schizophrenia treatment?

Background

Cognitive impairment is a widespread feature of schizophrenia, affecting nearly 80 % of patients. Prior research has linked the anticholinergic burden of psychiatric medications to these cognitive deficits. However, the impact of the anticholinergic burden from medications for physical morbidity remains underexplored. This study aimed to evaluate the anticholinergic burden of psychiatric and physical medications in patients with schizophrenia and assess its impact on cognitive function.

Methods

A total of 178 patients with schizophrenia were recruited. The assessments included an ad hoc questionnaire for collecting demographic and clinical data. Anticholinergic burden was evaluated using the cumulative Drug Burden Index (cDBI) for each participant, and cognitive function was assessed using MATRICS. Psychopathology was measured using the PANSS, CDSS, CAINS, and the CGI-S. Statistical analysis included Student's t-tests, ANOVA, Pearson correlations, and multiple linear regressions.

Results

The average cDBI was 1.3 (SD = 0.9). The model developed explained 40.80 % of the variance. The variable with the greatest weight was the cDBI (B = -11.148, p = 0.010). Negative-expression (B = -2.740, p = 0.011) and negative-experiential (B = -1.175, p = 0.030) symptoms were also associated with lower global cognitive score. However, more years of education (B = 5.140, p < 0.001) and cigarettes per day (B = 1.331, p < 0.001) predicted a better global cognitive score.

Conclusion

This study identified specific predictors of global cognition in schizophrenia, with anticholinergic burden emerging as the strongest factor. Our findings underscore the importance of considering the anticholinergic burden of treatments, in addition to negative symptoms, when designing interventions to optimize or maintain cognitive function in patients with schizophrenia.

Clinical Assessment Interview for Negative Symptoms (CAINS): A Systematic Review of Measurement Properties

BACKGROUND AND HYPOTHESIS

Negative symptoms are very important for the overall loss of functioning observed in patients with schizophrenia. There is a need for valid tools to assess these symptoms.

STUDY DESIGN

We used the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) systematic review guideline to evaluate the quality of the clinical assessment interview for negative symptoms (CAINS) as a clinician-rated outcome measurement (ClinROM).

STUDY RESULTS

The search strategy resulted in the retrieval of 13 articles, 11 of which were included in this evaluation. In terms of risk of bias, most articles reported on measures of internal consistency and construct validity, which were overall of good quality. Structural validity, reliability, measurement error, and cross-cultural validity were reported with less than optimum quality. There was a risk of bias in ClinROM development. According to the updated criteria of good measurement properties, structural validity, internal consistency, and reliability showed good results. In contrast, hypothesis testing was somewhat poorer. Results for cross-cultural validity were indeterminate. According to the updated GRADE approach from the COSMIN group the scale received a moderate grade.

CONCLUSIONS

The COSMIN standard allows a judgment of the CAINS as an instrument with the potential to be recommended for use, but which requires further research to assess its quality, in particular in the domains of content validity, internal consistency, and cross-cultural validity.

The Swedish version of the Motivation and Pleasure Scale self-report (MAP-SR): psychometric properties in patients with schizophrenia or depression

PURPOSE

Negative symptoms are commonly regarded as a symptom dimension belonging to schizophrenia spectrum disorders but are also present in depression. The recently developed Clinical Assessment Interview for Negative Symptoms (CAINS) has shown to be reliable and valid. A corresponding self-report questionnaire has also been developed, named the Motivation and Pleasure Scale - Self Report (MAP-SR). The purpose was to evaluate the psychometric properties of the Swedish version of the MAP-SR in patients with either schizophrenia or depression.

MATERIALS AND METHODS

The MAP-SR was translated to Swedish. Participants were 33 patients with schizophrenia spectrum disorders and 52 patients with a depressive disorder and they completed the MAP-SR, the CAINS and other measures assessing adjacent psychopathology, functioning and cognition.

RESULTS

The internal consistency for the MAP-SR was adequate in both groups (schizophrenia spectrum α = .93, depressive disorder α = .82). Furthermore, the MAP-SR had a large correlation to the motivation and pleasure subscale of the CAINS in patients with schizophrenia disorders (r = -0.75, p < .001), however among patients with depression this correlation was medium-to-large (r = -0.48, p < 0.001).

CONCLUSIONS

Findings suggest that the Swedish version of the MAP-SR shows promise as a useful measure of motivation and pleasure, especially in patients with schizophrenia spectrum disorders. Furthermore, results also suggest that the MAP-SR does not assess negative symptoms specifically, but that there is an overlap between depressive and negative symptoms.

PsiOvi Staging Model for Schizophrenia (PsiOvi SMS): A New Internet Tool for Staging Patients with Schizophrenia

BACKGROUND

One of the challenges of psychiatry is the staging of patients, especially those with severe mental disorders. Therefore, we aim to develop an empirical staging model for schizophrenia.

METHODS

Data were obtained from 212 stable outpatients with schizophrenia: demographic, clinical, psychometric (PANSS, CAINS, CDSS, OSQ, CGI-S, PSP, MATRICS), inflammatory peripheral blood markers (C-reactive protein, interleukins-1RA and 6, and platelet/lymphocyte [PLR], neutrophil/lymphocyte [NLR], and monocyte/lymphocyte [MLR] ratios). We used machine learning techniques to develop the model (genetic algorithms, support vector machines) and applied a fitness function to measure the model's accuracy (% agreement between patient classification of our model and the CGI-S).

RESULTS

Our model includes 12 variables from 5 dimensions: 1) psychopathology: positive, negative, depressive, general psychopathology symptoms; 2) clinical features: number of hospitalizations; 3) cognition: processing speed, visual learning, social cognition; 4) biomarkers: PLR, NLR, MLR; and 5) functioning: PSP total score. Accuracy was 62% (SD = 5.3), and sensitivity values were appropriate for mild, moderate, and marked severity (from 0.62106 to 0.6728).

DISCUSSION

We present a multidimensional, accessible, and easy-to-apply model that goes beyond simply categorizing patients according to CGI-S score. It provides clinicians with a multifaceted patient profile that facilitates the design of personalized intervention plans.

Do the negative symptoms of schizophrenia reflect reduced responsiveness to reward? Examination using a reward prediction error (RPE) task

BACKGROUND

A leading theory of the negative symptoms of schizophrenia is that they reflect reduced responsiveness to rewarding stimuli. This proposal has been linked to abnormal (reduced) dopamine function in the disorder, because phasic release of dopamine is known to code for reward prediction error (RPE). Nevertheless, few functional imaging studies have examined if patients with negative symptoms show reduced RPE-associated activations.

METHODS

Matched groups of DSM-5 schizophrenia patients with high negative symptom scores (HNS, N = 27) or absent negative symptoms (ANS, N = 27) and healthy controls (HC, N = 30) underwent fMRI scanning while they performed a probabilistic monetary reward task designed to generate a measure of RPE.

RESULTS

In the HC, whole-brain analysis revealed that RPE was positively associated with activation in the ventral striatum, the putamen, and areas of the lateral prefrontal cortex and orbitofrontal cortex, among other regions. Group comparison revealed no activation differences between the healthy controls and the ANS patients. However, compared to the ANS patients, the HNS patients showed regions of significantly reduced activation in the left ventrolateral and dorsolateral prefrontal cortex, and in the right lingual and fusiform gyrus. HNS and ANS patients showed no activation differences in ventral striatal or midbrain regions-of-interest (ROIs), but the HNS patients showed reduced activation in a left orbitofrontal cortex ROI.

CONCLUSIONS

The findings do not suggest that a generalized reduction of RPE signalling underlies negative symptoms. Instead, they point to a more circumscribed dysfunction in the lateral frontal and possibly the orbitofrontal cortex.

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.

What factors should we modify to promote high functioning and prevent functional decline in people with schizophrenia?

Background

Since research in schizophrenia mainly focuses on deficits and risk factors, we need studies searching for high-functioning protective factors. Thus, our objective was to identify protective (PFs) and risk factors (RFs) separately associated with high (HF) and low functioning (LF) in patients with schizophrenia.

Methods

We collected information (sociodemographic, clinical, psychopathological, cognitive, and functional) from 212 outpatients with schizophrenia. Patients were classified according to their functional level (PSP) as HF (PSP > 70, n = 30) and LF (PSP ≤ 50, n = 95). Statistical analysis consisted of Chi-square test, Student's t-test, and logistic regression.

Results

HF model: variance explained: 38.4-68.8%; PF: years of education (OR = 1.227). RFs: receiving a mental disability benefit (OR = 0.062) and scores on positive (OR = 0.719), negative-expression (OR = 0.711), and negative-experiential symptoms (OR = 0.822), and verbal learning (OR = 0.866). LF model: variance explained: 42.0-56.2%; PF: none; RFs: not working (OR = 6.900), number of antipsychotics (OR = 1.910), and scores on depressive (OR = 1.212) and negative-experiential symptoms (OR = 1.167).

Conclusion

We identified specific protective and risk factors for high and low functioning in patients with schizophrenia and confirmed that high functioning factors are not necessarily the opposite of those associated with low functioning. Only negative experiential symptoms are a shared and inverse factor for high and low functioning. Mental health teams must be aware of protective and risk factors and try to enhance or reduce them, respectively, to help their patients improve or maintain their level of functioning.

Bridge centrality network structure of negative symptoms in people with schizophrenia

Negative symptoms are complex psychopathology. Although evidence generally supported the NIMH five consensus domains, research seldom examined measurement invariance of this model, and domain-specific correspondence across multiple scales. This study aimed to examine the interrelationship between negative symptom domains captured by different rating scales, and to examine the domain-specific correspondence across multiple scales. We administered the Brief Negative Symptom Scale (BNSS), the Self-evaluation of Negative Symptoms (SNS), and the Scale for Assessment of Negative Symptoms (SANS) to 204 individuals with schizophrenia. We used network analysis to examine the interrelationship between negative symptom domains. Besides regularized partial correlation network, we estimated bridge centrality indices to investigate domain-specific correspondence, while taking each scale as an independent community. The regularized partial correlation network showed that the SNS nodes clustered together, whereas the SANS and the BNSS nodes intermingled together. The SANS attention domain lied at the periphery of the network according to the Fruchterman-Reingold algorithm. The SANS anhedonia-asociality (strength = 1.48; EI = 1.48) and the SANS affective flattening (strength = 1.06; EI = 1.06) had the highest node strength and EI. Moreover, the five nodes of the BNSS bridged the nodes of the SANS and the SNS. BNSS blunted affect (strength = 0.76; EI = 0.76) and SANS anhedonia-asociality (strength = 0.76; EI = 0.74) showed the highest bridge strength and bridge EI. The BNSS captures negative symptoms and bridges the symptom domains measured by the SANS and the SNS. The three scales showed domain-specific correspondence.

Revisiting the latent structure of negative symptoms in schizophrenia: Evidence from two second-generation clinical assessments

BACKGROUND

Negative symptoms are core symptom of schizophrenia, and many previous research studied the latent structure of negative symptoms based on a single measurement scale. Applying two second-generation negative symptom scales to the same sample can address measurement-invariance of latent structure.

METHODS

Three-hundred-and-five schizophrenia patients were assessed using the CAINS and the BNSS. Confirmatory Factor Analysis (CFA) tested four competing factor-models: (1) a 1-factor model; (2) a 2-factor model comprising the motivation and pleasure (MAP) domain and the diminished expression (EXP) domain; (3) a 5-factor model comprising anhedonia, avolition, asociality, blunted affect and alogia; (4) a hierarchical model comprising the "first-order" 5-domain factors and the "second-order" MAP &amp; EXP factors.

RESULTS

The CFA results for the data of the CAINS showed that the 2-factor model had the best data fit over the other competing models. The CFA using the BNSS data in the same sample also supported the superiority of the 2-factor model. Lastly, after combining the items of the BNSS and CAINS together in the same sample for CFA, the 2-factor model prevailed over the other competing models.

CONCLUSIONS

The 2-factor model appears to be measurement-invariant latent structure of negative symptoms. The novel method of combining the items of the CAINS and BNSS might have circumvented the possible imperfect construct of a single scale. Our findings support the MAP and EXP factors as the latent structure for negative symptoms.

Updated perspectives on the clinical significance of negative symptoms in patients with schizophrenia

INTRODUCTION

Negative symptoms in schizophrenia are associated with poor response to available treatments, poor quality of life, and functional outcome. Therefore, they represent a substantial burden for people with schizophrenia, their families, and health-care systems.

AREAS COVERED

In this manuscript, we will provide an update on the conceptualization, assessment, and treatment of this complex psychopathological dimension of schizophrenia.

EXPERT OPINION

Despite the progress in the conceptualization of negative symptoms and in the development of state-of-the-art assessment instruments made in the last decades, these symptoms are still poorly recognized, and not always assessed in line with current conceptualization. Every effort should be made to disseminate the current knowledge on negative symptoms, on their assessment instruments and available treatments whose efficacy is supported by research evidence. Longitudinal studies should be promoted to evaluate the natural course of negative symptoms, improve our ability to identify the different sources of secondary negative symptoms, provide effective interventions, and target primary and persistent negative symptoms with innovative treatment strategies. Further research is needed to identify pathophysiological mechanisms of primary negative symptoms and foster the development of new treatments.

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.

The role of BDNF and NGF plasma levels in first-episode schizophrenia: A longitudinal study

Neurotrophins have been proposed to be involved in biological mechanisms which might underlie different clinical outcomes in schizophrenia. The aims of the present study were to examine the BDNF/NGF plasma levels in a cohort of first-episode schizophrenia (FES) patients in remission as potential biological predictors of relapse; to study the associations between these neurotrophins and the symptomatology severity through different stages after a FES in two independent cohorts. 2EPs-Cohort: 69 first-episode in clinical remission were included. BDNF/NGF plasma levels and symptom severity were measured at enrollment and at 3-year or at the time of the second episode/relapse. FLAMM-PEPs-Cohort: 65 first-episodes were also included. BDNF/NGF and symptom severity were obtained at enrollment and 2-year follow-up. Symptomatology was assessed with the Marder-PANSS-Factor scores. Plasma neurotrophins did not differ significantly over time and neither BDNF/NGF were predictors of relapse. Besides, in remission stages, baseline BDNF levels showed significant correlations with both positive and negative symptoms (p<0.05); NGF, with negative symptomatology (p<0.01). Similarly, in the FLAMM-PEPs-Cohort, baseline BDNF/NGF levels showed significant correlations with negative symptoms (and not positive symptomatology) at follow-up (p<0.05). In both cohorts, lower levels correlated with higher symptom severity. Findings did not support a role for BDNF/NGF plasma levels as biomarkers of relapse in FES patients. Nevertheless, baseline BDNF/NGF may lead to be considered potentially useful biomarkers of long-term severity in schizophrenia and of the underlying illness traits, specially of negative symptomatology severity. More longitudinal studies in FES samples and adding a control group are warranted to replicate these findings.

Impact of Negative Symptoms on Functioning and Quality of Life in First Psychotic Episodes of Schizophrenia

Negative symptoms are not considered a unitary construct encompassing two different domains, diminished expression, and avolition-apathy. The aim of this study was to explore the relationships between each domain and psychosocial functioning and quality of life in people with a first psychotic episode of schizophrenia. In total, 61 outpatients were assessed with the Clinical Assessment Interview for Negative Symptoms (CAINS), The Functioning Assesment Short Test (FAST) and The Quality of Life Scale (QLS). The mean global score for CAINS was 21.5 (SD: 15.6), with a CAINS Avolition-Apathy (MAP) score of 17.0 (SD: 11.8), and CAINS Diminished Expression (EXP) score of 4.5 (SD: 5.0). The mean FAST score was 31.9 (SD: 18.9), and 41.1 (SD: 17.9) for QLS. Linear regression analysis revealed a significant (F(4,53) = 15.65, p < 0.001) relationship between MAP and EXP CAINS’ score and FAST score. CAINS-MAP was more predictive of FAST scores (β = 0.44, p = 0.001) than CAINS-EXP (β = 0.37, p = 0.007). Linear regression analysis for QLS revealed a significant model (F(4,56) = 29.29, p < 0.001). The standardized regression weight for the CAINS-MAP was around three times greater (β = −0.63, p < 0.001) than for CAINS-EXP (β = −0.24, p = 0.024). The two different domains are associated differently with functionality and quality of life.

Validation of a European Spanish adaptation of the Apathy Evaluation Scale-self-rated version (AES-S) in patients with schizophrenia

INTRODUCTION

Apathy is a negative symptom of schizophrenia and is associated with poor real world functioning. Therefore, it is important to have validated psychometric instruments to assess this symptom. This is the first study to validate the Spanish adaptation of the self-rated version of the Apathy Assessment Scale (AES-S) in patients with schizophrenia.

MATERIALS AND METHODS

Naturalistic, cross-sectional, validation study in 104 patients with schizophrenia evaluated using the following scales: Clinical Global Impression-Severity (CGI-S), Personal and Social Performance (PSP), Clinical Assessment Interview for Negative Symptoms (CAINS), Self-report of Negative Symptoms (SNS), Motivation and Pleasure Scale-Self-Report (MAP-SR), Calgary Depression Scale for Schizophrenia (CDSS), and Apathy Evaluation Scale-self-rated version (AES-S).

RESULTS

Reliability: Internal consistency (Cronbach's alpha) was 0.908. Convergent validity: The Pearson correlation coefficient between AES-S and CAINS-MAP total scores was -0.483 (p<0.001). For SNS, total and avolition subscale scores were -0.803 and -0.639 (p<0.001), respectively. With the MAP-SR, the correlation coefficient was -0.727 (p<0.001). Divergent validity: The Pearson correlation coefficient between AES-S and PSP total scores was 0.504 (p<0.001). Furthermore, with the CDSS, the correlation coefficient was -0.431 (p<0.001). Discriminant validity: The AES-S discriminated between different levels of illness severity according to CGI-S scores. Factor analysis: A three-component solution explained 57.32% of the variance. Pearson correlations between coefficients were 1-2=0.265, 1-3=0.464, and 2-3=0.060.

CONCLUSION

The Spanish AES-S is a reliable and valid instrument for assessing apathy in Spanish patients with schizophrenia. It seems to be appropriate for use in everyday clinical practice as a means of monitoring apathy in these patients.

Validation of a European Spanish-version of the Self-Evaluation of Negative Symptoms (SNS) in patients with schizophrenia

INTRODUCTION

Negative symptoms can be grouped into five domains: apathy/avolition, anhedonia, asociality, alogia, and affective flattening. There are few validate self-rated measures that assess these five dimensions. Therefore, this study aimed to validate the Self-Evaluation of Negative Symptoms (SNS) in Spanish patients with schizophrenia.

MATERIAL AND METHODS

Cross-sectional, validation study in 104 outpatients with schizophrenia evaluated using the Spanish version of the following scales: Clinical Assessment Interview for Negative Symptoms (CAINS), Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression Scale for Schizophrenia (CGI-SCH), Personal and Social Performance (PSP), Motivation and Pleasure Scale - Self-Report (MAP-SR), 36-item Short-Form Health Survey (SF-36) and the Self-Evaluation of Negative Symptoms (SNS).

RESULTS RELIABILITY

Internal consistency (Cronbach's alpha) was 0.915. Convergent validity: The Pearson correlation coefficient between MAP-SR and SNS Total scores was 0.660 (p<0.001). For PANSS-N, the correlation was 0.437 (p<0.005) and with the CAINS-Total was 0.478 (p<0.005). Divergent validity: The Pearson correlation coefficient between SNS and PSP was r=-0.372 (p≤0.001), and with SF-36 Physical and Mental Summary Component scores were r=-0.213 (p=0.066) and r=-0.144 (p=0.219), respectively. Discriminant validity: SNS Total scores were significantly statistically different according to the severity of the negative symptomatology rated by the CGI-SCH negative scale (p<0.001).

CONCLUSION

The SNS is a reliable and valid instrument to self-rate the five domains of negative symptoms in patients with schizophrenia and seems to be appropriate for use in everyday clinical practice as a complementary measure to the evaluation performed by the clinician.

Validation of the French Clinical Assessment Interview for Negative Symptoms in a Sample of Stable French Individuals With Schizophrenia

OBJECTIVES

The Clinical Assessment Interview for Negative Symptoms (CAINS) is an interview-based instrument evaluating the existence and severity of negative symptoms in people diagnosed with schizophrenia or schizoaffective disorder. The aim of this study is to translate and validate a French version of the CAINS in a French sample of outpatients diagnosed with schizophrenia or schizoaffective disorder.

METHODS

In this study, we included 84 outpatients with a diagnosis of schizophrenia from the University Department of Adult Psychiatry in Montpellier, France. All participants were assessed for the severity of negative symptoms as well as level of depression. Psychometric properties of the French CAINS were investigated including its factor structure, internal consistency, and interrater and test-retest reliabilities. We also determined the discriminant and convergent validity.

RESULTS

Exploratory factor analysis and parallel analysis reproduced the two-factor model, and explained 43.55% of the total score variation with good internal consistency (Cronbach α of 0.87). Both interrater and test-retest reliabilities were high for the CAINS and its subscales (intraclass correlation coefficient range, 0.89-0.99). The standard errors of measurement and minimal detectable change were also investigated. Convergent validity of the CAINS was underpinned by correlations obtained with various measures of negative symptoms. Adequate discriminant validity was established by showing that the CAINS did not correlate with positive symptoms.

CONCLUSION

Overall, our results obtained were similar to those found in the original study of the CAINS. Structural analyses also replicated the two-factor model of the CAINS. Our results indicate that the French CAINS has robust psychometric properties and is a valid tool for evaluating negative symptoms in French-speaking individuals diagnosed with schizophrenia.

Negative schizophrenic symptoms as prefrontal cortex dysfunction: Examination using a task measuring goal neglect

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Negative schizophrenic symptoms have been considered to reflect prefrontal cortex dysfunction.

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Functional imaging support for this theory is however weak, perhaps due to the tasks used.

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We examined negative symptom patients using a novel executive task measuring volitional behaviour.

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Comparison to patients without negative symptoms revealed prefrontal hypoactivation.

Background

The negative symptoms of schizophrenia have been proposed to reflect prefrontal cortex dysfunction. However, this proposal has not been consistently supported in functional imaging studies, which have also used executive tasks that may not capture key aspects of negative symptoms such as lack of volition.

Method

Twenty-four DSM-5 schizophrenic patients with high negative symptoms (HNS), 25 with absent negative symptoms (ANS) and 30 healthy controls underwent fMRI during performance of the Computerized Multiple Elements Test (CMET), a task designed to measure poor organization of goal directed behaviour or ‘goal neglect’. Negative symptoms were rated using the PANSS and the Clinical Assessment Interview for Negative Symptoms (CAINS).

Results

On whole brain analysis, the ANS patients showed no significant clusters of reduced activation compared to the healthy controls. In contrast, the HNS patients showed hypoactivation compared to the healthy controls in the left anterior frontal cortex, the right dorsolateral prefrontal cortex (DLPFC), the anterior insula bilaterally and the bilateral inferior parietal cortex. When compared to the ANS patients, the HNS patients showed reduced activation in the left anterior frontal cortex, the left DLPFC and the left inferior parietal cortex. After controlling for disorganization scores, differences remained in clusters in the left anterior frontal cortex and the bilateral inferior parietal cortex.

Conclusions

This study provides evidence that reduced prefrontal activation, perhaps especially in the left anterior frontal cortex, is a brain functional correlate of negative symptoms in schizophrenia. The simultaneous finding of reduced inferior parietal cortex activation was unexpected, but could reflect this region’s involvement in cognitive control, particularly the ‘regulative’ component of this.

A blinded validation of the Swedish version of the Clinical Assessment Interview for Negative Symptoms (CAINS)

PURPOSE

The Clinical Assessment Interview for Negative Symptoms (CAINS) was developed in order to advance the assessment of negative symptoms. The aim of this study was to validate the Swedish version of the CAINS.

MATERIALS AND METHODS

Thirty-four out-patients with a schizophrenia spectrum disorder were recruited. All patients were videotaped while interviewed with the CAINS and the Brief Psychiatric Rating Scale (BPRS). Another rater watched the video recordings in the reverse order, enabling a blinded design. The patients also filled in self-reported measures of depression, quality of life, and social and vocational functioning. We calculated inter-rater agreement and internal consistency for the CAINS. We also calculated validity measures by correlating the subscales Motivation and Pleasure (CAINS-MAP) and Expression (CAINS-EXP) to subscales of the BPRS.

RESULTS

The blinded inter-rater agreement for the CAINS total score was high (ICC = 0.92) but slightly lower for the expression subscale (ICC = 0.76). Cronbach's alpha was 0.84 for the total score. Convergent validity with the negative symptoms subscale of BPRS was different for the blinded and the unblinded data, with a CAINS-MAP correlation of 0.10 (p = 0.580) and a CAINS-EXP correlation of 0.48 (p = 0.004) in the blinded data. The unblinded data had a CAINS-MAP correlation of 0.38 (p = 0.026) and a CAINS-EXP correlation of 0.87 (p < 0.001). Self-rated measures of anhedonia correlated to CAINS-MAP with a coefficient of 0.68 (p < 0.001), while the CAINS-EXP only had a correlation of 0.16 (p = 0.366) to these measures.

CONCLUSION

The Swedish version of the CAINS displays adequate psychometric properties in line with earlier validation studies.

Factor structure and internal consistency of the Clinical Assessment Interview for Negative Symptoms (CAINS) on a sample of persons with psychotic disorders in Bosnia and Herzegovina

The assessment of negative symptoms is crucial for development of adequate therapeutic interventions. This is a challenging task due to complex clinical presentation and lack of reliable and valid instruments. This study examined the psychometric characteristics of the Clinical Assessment Interview for Negative Symptoms (CAINS). The sample consisted of 81 persons with schizophrenia or schizoaffective disorder recruited from two health institutions in the Sarajevo Canton: the Clinical Center of the University of Sarajevo and the Psychiatric Hospital of the Sarajevo Canton. The 13 CAINS items grouped into four factors (expression, motivation and satisfaction in the recreational domain, motivation and satisfaction with social relationships, motivation and satisfaction with job and education). The four-factor solution accounted for 87.83% of the variance of manifest items. The reliabilities of extracted factors were as follows: for motivation and satisfaction with social relationships α = 0.897, for motivation and satisfaction with job and education α = 0.961, for Motivation and satisfaction in the recreation domain α = 0.981, and for expression α = 0.938. The highest correlation between factors was found between Motivation and satisfaction with recreation and Motivation and satisfaction with social relationships. On the other hand, the lowest correlation was found between motivation and satisfaction with social relations and motivation and satisfaction with job and education. In conclusion, the study showed that the latent structure of CAINS is adequate, clearly interpretable, and consisted of four factors. The measure can be used for assessment of the negative symptoms in outpatients with psychosis in Bosnia and Herzegovina.

Cognitive, community functioning and clinical correlates of the Clinical Assessment Interview for Negative Symptoms (CAINS) in psychotic disorders

Negative symptoms are a core dimension of schizophrenia and other psychoses that account for a large degree of the poor functional outcomes related to these disorders. Newer assessment scales for negative symptoms, such as the Clinical Assessment Interview for Negative Symptoms (CAINS), provide evidence for separate dimensions of motivational and pleasure (MAP) and expression (EXP) dimensions. This study was aimed at extending the analysis of the clinical, functional and cognitive correlates of CAINS dimensions in a sample of patients with psychotic disorders (n = 98) and 50 healthy controls.A psychopathological evaluation was conducted by using the Comprehensive Assessment of Symptoms and History (CASH). To assess the extrapyramidal signs, the UKU scale was used. Community functioning was evaluated by means of real-world and functional attainment measures. Additionally, a full neuropsychological test battery was administered. Pearson correlation and hierarchical multiple linear regression analyses were performed to identify the influencing and predictive factors associated with the CAINS dimensions.The MAP and EXP dimensions showed strong associations with the Scale for the Assessment of Negative Symptoms (SANS) items and were not significantly associated with extra-pyramidal or cognitive deficits. The MAP and EXP CAINS dimensions revealed good predictive validity for real-world functioning and functional attainment measures.These findings suggest that the CAINS scale endorses good convergent validity for the assessment of negative symptoms and is very useful in the prediction of psychosocial functioning. In addition, the CAINS dimensions might provide advantages over old assessment scales on disentangling the complex associations between negative symptoms and cognitive impairment.

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.

Factorial Structure of the Serbian Version of the Clinical Assessment Interview for Negative Symptoms - Evidence for Three Factors of Negative Symptoms

Introduction: Negative symptoms are a common occurrence in patients with psychosis spectrum disorders. Previous analysis of the latent structure of the Clinical Assessment Interview for Negative Symptoms (CAINS) - which was developed to advance the assessment of negative symptomatology - showed two underlying sub-domains (Motivation and Pleasure; Expression). Recent findings indicate that a more complex structure might be more applicable. Aim: To evaluate the psychometric properties of the Serbian version of the CAINS in a sample of outpatients (N = 67) with psychosis spectrum disorders. Materials and Methods: Negative symptoms and general level of psychopathology were assessed with Serbian translations of the CAINS, the 53-item version of the Brief Symptom Inventory (BSI), and the 24-item version of the Brief Psychiatric Rating Scale (BPRS). Principal component analysis (PCA) was carried out on the CAINS items, and correlation analyses were done to assess its convergent and discriminant validity. Results: Our results showed an excellent internal consistency (Cronbach's alpha = 0.92). PCA revealed a three-component solution consisting of Expressiveness and Motivation for Social and Family Relationships (Factor 1), Motivation for Vocational Activities (Factor 2), and Motivation for Recreation (Factor 3). Convergent validity was supported by significant correlations with the Negative symptoms domain of the BPRS (Factor 1, 0.695, p < 0.01; Factor 2, 0.352, p < 0.05; Factor 3, 0.452, p < 0.01). When assessing discriminant validity, weak correlations were found with BPRS and BSI scores. Conclusion: The Serbian version of CAINS is a valid, reliable and useful tool for the assessment of negative symptomatology. Our findings support a three-factor structure of CAINS, which indicates that the construct is more complex than envisaged by the original conceptualization of two distinct factors.

Cognitive impairment and C-reactive protein in clinically stable schizophrenia outpatients: a focus on sex differences

Although previous findings identified an association between C-reactive protein (CRP) levels, and impaired cognitive functions in patients with schizophrenia (SZ), little is currently known about the relationship between inflammation, cognition, and sex in SZ. The current study aimed to explore the association between peripheral inflammation and cognitive impairment in SZ as a function of sex. The sample included 132 clinically stable patients with SZ, of whom 82 were males (62.1%) and 50 females (37.9%). Sociodemographic data were collected, an accurate assessment was performed using the Positive and Negative Syndrome (PANSS), Clinical Assessment Interview for Negative Symptoms (CAINS), and Calgary Depression (CDS) scales, and the MATRICS Consensus Cognitive Battery (MCCB), and CRP levels were tested. A Pearson correlation and multiple regression analyses, including potential confounding factors, were performed. We found an inverse association between CRP levels and performance on visual learning (r = − 0.386, p = 0.006) domain in female patients only, whereas no correlations were found in males. The regression model for women retained age (β = − 0.319, p = 0.017), the CAINS-MAP score (β = − 0.247, p = 0.070), and the CRP (β = − 0.321, p = 0.013) as predictors of visual learning. Our results suggest the possible existence of sex-specific modulation of the association between systemic inflammation and the cognitive features of the illness.

Validation of a European Spanish-version of the Self-Evaluation of Negative Symptoms (SNS) in patients with schizophrenia

INTRODUCTION

Negative symptoms can be grouped into five domains: apathy/avolition, anhedonia, asociality, alogia, and affective flattening. There are few validate self-rated measures that assess these five dimensions. Therefore, this study aimed to validate the Self-Evaluation of Negative Symptoms (SNS) in Spanish patients with schizophrenia.

MATERIAL AND METHODS

Cross-sectional, validation study in 104 outpatients with schizophrenia evaluated using the Spanish version of the following scales: Clinical Assessment Interview for Negative Symptoms (CAINS), Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression Scale for Schizophrenia (CGI-SCH), Personal and Social Performance (PSP), Motivation and Pleasure Scale - Self-Report (MAP-SR), 36-item Short-Form Health Survey (SF-36) and the Self-Evaluation of Negative Symptoms (SNS).

RESULTS RELIABILITY

Internal consistency (Cronbach's alpha) was 0.915. Convergent validity: The Pearson correlation coefficient between MAP-SR and SNS Total scores was 0.660 (p<0.001). For PANSS-N, the correlation was 0.437 (p<0.005) and with the CAINS-Total was 0.478 (p<0.005). Divergent validity: The Pearson correlation coefficient between SNS and PSP was r=-0.372 (p≤0.001), and with SF-36 Physical and Mental Summary Component scores were r=-0.213 (p=0.066) and r=-0.144 (p=0.219), respectively. Discriminant validity: SNS Total scores were significantly statistically different according to the severity of the negative symptomatology rated by the CGI-SCH negative scale (p<0.001).

CONCLUSION

The SNS is a reliable and valid instrument to self-rate the five domains of negative symptoms in patients with schizophrenia and seems to be appropriate for use in everyday clinical practice as a complementary measure to the evaluation performed by the clinician.

Validation of a European Spanish adaptation of the Apathy Evaluation Scale-self-rated version (AES-S) in patients with schizophrenia

INTRODUCTION

Apathy is a negative symptom of schizophrenia and is associated with poor real world functioning. Therefore, it is important to have validated psychometric instruments to assess this symptom. This is the first study to validate the Spanish adaptation of the self-rated version of the Apathy Assessment Scale (AES-S) in patients with schizophrenia.

MATERIALS AND METHODS

Naturalistic, cross-sectional, validation study in 104 patients with schizophrenia evaluated using the following scales: Clinical Global Impression-Severity (CGI-S), Personal and Social Performance (PSP), Clinical Assessment Interview for Negative Symptoms (CAINS), Self-report of Negative Symptoms (SNS), Motivation and Pleasure Scale-Self-Report (MAP-SR), Calgary Depression Scale for Schizophrenia (CDSS), and Apathy Evaluation Scale-self-rated version (AES-S).

RESULTS

Reliability: Internal consistency (Cronbach's alpha) was 0.908. Convergent validity: The Pearson correlation coefficient between AES-S and CAINS-MAP total scores was -0.483 (p<0.001). For SNS, total and avolition subscale scores were -0.803 and -0.639 (p<0.001), respectively. With the MAP-SR, the correlation coefficient was -0.727 (p<0.001). Divergent validity: The Pearson correlation coefficient between AES-S and PSP total scores was 0.504 (p<0.001). Furthermore, with the CDSS, the correlation coefficient was -0.431 (p<0.001). Discriminant validity: The AES-S discriminated between different levels of illness severity according to CGI-S scores. Factor analysis: A three-component solution explained 57.32% of the variance. Pearson correlations between coefficients were 1-2=0.265, 1-3=0.464, and 2-3=0.060.

CONCLUSION

The Spanish AES-S is a reliable and valid instrument for assessing apathy in Spanish patients with schizophrenia. It seems to be appropriate for use in everyday clinical practice as a means of monitoring apathy in these patients.

Association of the brain-derived neurotrophic factor Val66Met polymorphism with negative symptoms severity, but not cognitive function, in first-episode schizophrenia spectrum disorders

Objective

A functional polymorphism of the brain-derived neurotrophic factor gene (BDNF) Val66Met has been associated with cognitive function and symptom severity in patients with schizophrenia. It has been suggested that the Val66Met polymorphism has a role as a modulator in a range of clinical features of the illness, including symptoms severity, therapeutic responsiveness, age of onset, brain morphology and cognitive function. However, little work has been done in first-episode schizophrenia (FES) spectrum disorders. The objective of this study is to investigate the association of the BDNF Val66Met polymorphism on cognitive function and clinical symptomatology in FES patients.

Methods

Using a cross-sectional design in a cohort of 204 patients with FES or a schizophrenia spectrum disorder and 204 healthy matched controls, we performed BDNF Val66Met genotyping and tested its relationship with cognitive testing (attention, working memory, learning/verbal memory and reasoning/problem-solving) and assessment of clinical symptom severity.

Results

There was no significant influence of the BDNF allele frequency on cognitive factor scores in either patients or controls. An augmented severity of negative symptoms was found in FES patients that carried the Met allele.

Conclusions

The results of this study suggest that in patients with a first-episode of schizophrenia or a schizophrenia spectrum disorder, the BDNF Val66Met polymorphism does not exert an influence on cognitive functioning, but is associated with negative symptoms severity. BDNF may serve as suitable marker of negative symptomatology severity in FES patients within the schizophrenia spectrum.

The relationship between depressive symptoms and negative symptoms in people with non-affective psychosis: a meta-analysis

The negative symptoms of psychosis and depressive symptomatology share several features, e.g. low motivation, apathy and reduced activity. Understanding the associations between these two sets of symptoms will support improved assessment and the development of interventions targeting these difficulties in people with psychosis. This is the first large systematic review and meta-analysis to quantify the relationship between these two categories of symptoms, as measured in studies to date. PsycInfo, Embase and Medline were systematically searched to identify eligible studies. Inclusion criteria ensured the studies measured both depression and negative symptoms using validated measures in a sample of over 8000 participants with non-affective psychosis diagnoses. The search led to 2020 records being screened and 56 included in the meta-analysis and review. Both meta-analyses and meta-regressions were conducted to explore the main effect and potential moderating variables. A clear pattern emerges showing that higher ratings of negative symptoms are associated with higher levels of depressive symptoms, with a small effect [standardised effect size = 0.19, p < 0.05). This did not vary greatly with the measures used (SES = 0.19-0.26) and was not moderated by demographic variables or quality ratings. Interestingly, higher depressive symptoms predict a significant relationship with co-occurring negative symptoms. However, higher negative symptoms predict that it is less likely there will be a relationship with co-occurring depressive symptoms. Heterogeneity was high across these analyses. The findings support the adoption of a symptom-specific approach to understanding the interplay between negative and depressive symptoms in psychosis, to improve assessment and intervention.

Network Analysis Reveals the Latent Structure of Negative Symptoms in Schizophrenia

Prior studies using exploratory factor analysis provide evidence that negative symptoms are best conceptualized as 2 dimensions reflecting diminished motivation and expression. However, the 2-dimensional model has yet to be evaluated using more complex mathematical techniques capable of testing structure. In the current study, network analysis was applied to evaluate the latent structure of negative symptoms using a community-detection algorithm. Two studies were conducted that included outpatients with schizophrenia (SZ; Study 1: n = 201; Study 2: n = 912) who were rated on the Brief Negative Symptom Scale (BNSS). In both studies, network analysis indicated that the 13 BNSS items divided into 6 negative symptom domains consisting of anhedonia, avolition, asociality, blunted affect, alogia, and lack of normal distress. Separation of these domains was statistically significant with reference to a null model of randomized networks. There has been a recent trend toward conceptualizing the latent structure of negative symptoms in relation to 2 distinct dimensions reflecting diminished expression and motivation. However, the current results obtained using network analysis suggest that the 2-dimensional conceptualization is not complex enough to capture the nature of the negative symptom construct. Similar to recent confirmatory factor analysis studies, network analysis revealed that the latent structure of negative symptom is best conceptualized in relation to the 5 domains identified in the 2005 National Institute of Mental Health consensus development conference (anhedonia, avolition, asociality, blunted affect, and alogia) and potentially a sixth domain consisting of lack of normal distress. Findings have implications for identifying pathophysiological mechanisms and targeted treatments.

Assessing negative symptoms in schizophrenia: Validity of the clinical assessment interview for negative symptoms in Singapore

This study aimed to examine the validity of the Clinical Assessment Interview for Negative Symptoms (CAINS) in Singapore. 274 participants with schizophrenia were assessed on the CAINS, Scale for the Assessment of Negative Symptoms (SANS), Positive and Negative Syndrome Scale (PANSS), Calgary Depression Scale for Schizophrenia (CDSS), Social and Occupational Functioning Assessment Scale (SOFAS) and the Simpson-Angus Extrapyramidal Side Effects Scale (SES). Factor analyses were conducted and Cronbach's coefficient alpha was calculated. Spearman's correlation coefficient was used to assess correlations. The 2-factor model of the CAINS failed to fit our data. Exploratory factor analysis of a randomly selected split-half of the sample yielded four factors: motivation-pleasure (MAP) social, MAP vocational, MAP recreational and expression (EXP), accounting for 73.94% of the total variance. Confirmatory factor analysis on the remaining sample supported this factor structure. Cronbach's alpha for the CAINS was 0.770. Significant correlations were observed between the CAINS total and the SANS total and PANSS negative subscale scores. Good divergent validity was shown by insignificant correlations with PANSS positive subscale score and CDSS total score. The MAP social and recreational factor scores had moderate correlations with the SANS anhedonia-asociality subscale scores, whereas the MAP vocational factor had the highest correlation with the avolition-apathy subscale of the SANS. EXP factor score correlated strongly with the SANS affective flattening and alogia subscales scores. In conclusion, the CAINS has good psychometric properties and can be used by clinicians to assess negative symptoms in individuals with schizophrenia in the local population.

Revisiting the persistent negative symptoms proxy score using the Clinical Assessment Interview for Negative Symptoms

OBJECTIVE

The present study aimed to validate a severity cut-off of negative symptoms for persistent negative symptoms (PNS) identification using the Clinical Assessment Interview for Negative Symptoms (CAINS).

METHOD

A total of 206 patients with schizophrenia were recruited and divided into the PNS group (n = 57) and the Non-PNS group (n = 149) using PNS criteria based on the SANS and the SAPS. To determine the appropriate cut-offs on the CAINS in identifying PNS, Receiver Operating Characteristic (ROC) curve analysis was conducted in the PNS and Non-PNS groups.

RESULTS

Our results showed that the cutoffs for identifying PNS on the CAINS total score, the Motivation and Pleasure (MAP) subscale score and the Expression (EXP) subscale score were 25, 17, and 5 respectively. Area Under the Curve (AUC) analysis indicated excellent discrimination of the PNS group from the Non-PNS group using the cut-off for the CAINS total score. However, discrimination was somewhat better for the MAP subscale score than the EXP subscale score. The Positive Predictive Value (PPV) and Negative Predictive Value (NPV) of the MAP subscale were 81.54% and 97.16%.

CONCLUSION

We found that the cut-off scores derived from the CAINS to identify PNS are comparable to existing scales. The CAINS offers an alternative means in identifying PNS patients in clinical trials that overcomes methodological and conceptual limitations of older scales.

Elevated C-reactive protein as a predictor of a random one-year clinical course in the first ten years of schizophrenia

We investigate whether C-reactive protein (CRP) levels could predict the clinical course of patients with schizophrenia in a prospective study of 50 stable outpatients during a random 1-year period within the first 10 years of illness. Positive, negative, depressive, and cognitive symptoms were evaluated. Patients with low-grade inflammation (CRP = 3-10 mg/L; 28%) at baseline showed significant worsening of PANSS-positive and general psychopathology at 1-year follow-up compared with those with CRP ≤ 3 mg/L. Elevated CRP may be a biomarker of poor 1-year clinical course in patients with schizophrenia.

Cross Cultural Validation and Extension of the Clinical Assessment Interview for Negative Symptoms (CAINS) in the Chinese Context: Evidence from a Spectrum Perspective

The Clinical Assessment Interview for Negative Symptoms (CAINS) was designed in accordance with the recent theory and research in social affective neuroscience and to address the psychometric and conceptual limitations of other instruments assessing negative symptoms. The present study aimed to provide a large-scale validation of the CAINS in China and examine its applicability and validity evidence across the schizophrenia spectrum. Using confirmatory factor analysis, our results replicated the original findings in the US development samples that the CAINS possesses a stable 2-factor structure, namely "motivation/pleasure" and "expression". We also found significant correlations between the CAINS and other negative symptom measures. The CAINS demonstrated good discriminant validity in differentiating negative symptoms in people with schizophrenia, nonpsychotic first-degree relatives and people with social anhedonia. People with schizophrenia exhibited significantly higher CAINS subscale scores than first-degree relatives and healthy controls. In addition, first-degree relatives had higher "motivation/pleasure" scores than healthy controls. The "motivation/pleasure" subscale scores of individuals with social anhedonia were also significantly higher than healthy controls.

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.

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.

The course of negative symptoms in first-episode schizophrenia and its predictors: A prospective two-year follow-up study

AIMS

This study aimed to investigate the course of negative symptoms and its stability over a two-year period following a first-episode schizophrenia (FES) and the possible predictors of higher severity in this symptomatology after this period.

METHODS

In this longitudinal two-year prospective follow-up study we included 268 patients with a FES, according to DSM-IV. Analysis of variance was conducted in patients who completed the full follow-up to study changes in negative symptoms over three visits. Regression analyses were conducted to show correlates and potential predictors of negative symptoms at two-year follow-up.

RESULTS

There was a significant effect for time in negative symptomatology, which was less severe at one-year follow-up after a FES and remained stable up to two years (Time 1>Time 2>Time 3); F(2,151)=20.45, p<0.001. Poorer premorbid adjustment (p=0.01) and higher negative symptoms at baseline (p<0.001) made a significant contribution to the changes in the negative symptoms severity at two-years after a FES (R²=0.21, p<0.001).

CONCLUSIONS

We found a reduction in the negative symptomatology at one-year after a FES. This change remained stable at two-year. Our results suggested that the presence of this symptomatology early in the course of the illness, together with a poorer premorbid adjustment, predict more severe negative symptoms at mid-term outcome.

Current developments and challenges in the assessment of negative symptoms

Reliable and valid assessment of negative symptoms is crucial to further develop etiological models and improve treatments. Our understanding of the concept of negative symptoms has undergone significant advances since the introduction of quantitative assessments of negative symptoms in the 1980s. These include the conceptualization of cognitive dysfunction as separate from negative symptoms and the distinction of two main negative symptom factors (avolition and diminished expression). In this review we provide an overview of existing negative symptom scales, focusing on both observer-rated and self-rated measurement of negative symptoms. We also distinguish between measures that assess negative symptoms as part of a broader assessment of schizophrenia symptoms, those specifically developed for negative symptoms and those that assess specific domains of negative symptoms within and beyond the context of psychotic disorders. We critically discuss strengths and limitations of these measures in the light of some existing challenges, i.e. observed and subjective symptom experiences, the challenge of distinguishing between primary and secondary negative symptoms, and the overlap between negative symptoms and related factors (e.g. personality traits and premorbid functioning). This review is aimed to inform the ongoing development of negative symptom scales.

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.

A Psychometric Comparison of the Clinical Assessment Interview for Negative Symptoms and the Brief Negative Symptom Scale

In 2005, the National Institute of Mental Health held a consensus development conference on negative symptoms of schizophrenia. Among the important conclusions of this meeting were that there are at least 5 commonly accepted domains of negative symptoms (blunted affect, alogia, avolition, anhedonia, asociality) and that new rating scales were needed to adequately assess these constructs. Two next-generation negative symptom scales resulted from this meeting: the Brief Negative Symptom Scale (BNSS) and Clinical Assessment Interview for Negative Symptoms (CAINS). Both measures are becoming widely used and studies have demonstrated good psychometric properties for each scale. The current study provides the first direct psychometric comparison of these scales. Participants included 65 outpatients diagnosed with schizophrenia or schizoaffective disorder who completed clinical interviews, questionnaires, and neuropsychological testing. Separate raters completed the BNSS and CAINS within the same week. Results indicated that both measures had good internal consistency, convergent validity, and discriminant validity. High correspondence was observed between CAINS and BNSS blunted affect and alogia items. Moderate convergence occurred for avolition and asociality items, and low convergence was seen among anhedonia items. Findings suggest that both scales have good psychometric properties, but that there are important distinctions among the items related to motivation and pleasure.

A Two-Factor Model Better Explains Heterogeneity in Negative Symptoms: Evidence from the Positive and Negative Syndrome Scale

Acknowledging separable factors underlying negative symptoms may lead to better understanding and treatment of negative symptoms in individuals with schizophrenia. The current study aimed to test whether the negative symptoms factor (NSF) of the Positive and Negative Syndrome Scale (PANSS) would be better represented by expressive and experiential deficit factors, rather than by a single factor model, using confirmatory factor analysis (CFA). Two hundred and twenty individuals with schizophrenia spectrum disorders completed the PANSS; subsamples additionally completed the Brief Negative Symptom Scale (BNSS) and the Motivation and Pleasure Scale—Self-Report (MAP-SR). CFA results indicated that the two-factor model fit the data better than the one-factor model; however, latent variables were closely correlated. The two-factor model’s fit was significantly improved by accounting for correlated residuals between N2 (emotional withdrawal) and N6 (lack of spontaneity and flow of conversation), and between N4 (passive social withdrawal) and G16 (active social avoidance), possibly reflecting common method variance. The two NSF factors exhibited differential patterns of correlation with subdomains of the BNSS and MAP-SR. These results suggest that the PANSS NSF would be better represented by a two-factor model than by a single-factor one, and support the two-factor model’s adequate criterion-related validity. Common method variance among several items may be a potential source of measurement error under a two-factor model of the PANSS NSF.