The five symptom dimensions and depression in schizophrenia

Associations between fearlessness about death and suicidal ideation in individuals with psychosis

BACKGROUND

Despite high rates of suicide among people with psychosis, relatively little is known about the mechanisms underlying the transition from suicidal ideation to behavior in this population. The Interpersonal Psychological Theory of Suicide (IPTS) proposes that fearlessness about death (FAD) may play a role in this relationship. The present study tested whether constructs of the IPTS [thwarted belongingness (TB), perceived burdensomeness (PB), and FAD] were associated with the severity of suicidal ideation in a sample of adults with histories of psychosis.

METHOD

261 adults with histories of psychosis completed measures of IPTS constructs, current severity of suicidal ideation, and history of suicidal attempts. We examined differences between those with past suicide attempts and those without and conducted regression analyses to evaluate the associations among TB, PB, FAD and severity of current suicidal ideation.

RESULTS

Contrary to expectations, a history of suicidal behavior was not uniquely associated with FAD. Regression analyses revealed TB × PB and FAD × PB interactions emerged as significant correlates of the severity of suicidal ideation, with the relationship between PB and suicidal ideation more pronounced at higher levels of FAD and TB. Interestingly, positive symptoms of psychosis were positively associated with PB.

IMPLICATIONS

This study provides support for broadening the investigation of FAD as a contributor to suicidal ideation in individuals with psychotic symptoms. Future research investigating the role of other contributors that may influence capability for suicide (e.g., impulsivity) may add additional understanding of suicide in this population.

Immune dysregulation is associated with symptom dimensions and cognitive deficits in schizophrenia: accessible evidence from complete blood count

BACKGROUND

Schizophrenia (SCZ) is a psychotic disorder with an unknown pathogenesis accompanied by varying degrees of cognitive deficits. Recent studies have shown that immune dysregulation plays an important role in developing symptoms and cognitive deficits in SCZ. This study aimed to determine the complete blood count (CBC), including white blood cells, neutrophils, monocytes, lymphocytes, platelets, neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and monocyte-lymphocyte ratio (MLR), in patients with SCZ and explore their correlations with SCZ symptom dimensions and cognitive function.

METHODS

Seventy-four patients with SCZ and 57 age- and sex-matched healthy controls with available demographic and clinical information were recruited for this study. Blood samples were collected, and symptom dimensions and cognitive function were evaluated using the Positive and Negative Syndrome Scale (PANSS) and MATRICS Consensus Cognitive Battery (MCCB) separately.

RESULTS

Our results demonstrate that SCZ patients showed higher monocyte counts, PLR, MLR, and worse performance in the total MCCB than healthy controls. Neutrophil and lymphocyte counts and NLR were positively related to symptom severity and negatively related to depressive symptoms. White blood cell (WBC) count, monocyte count, and MLR were positively correlated with cognitive performance in patients with SCZ.

CONCLUSION

In summary, this study suggests that cognitive deficits and symptom severity in patients were associated with dysregulation of immunity. Moreover, we found that WBC could be used as a marker for symptom severity and cognitive deficits in SCZ and that neutrophils are more closely related to the former and monocytes to the latter. We hope that clinicians will pay more attention to dysregulated immunity in patients with SCZ in the future.

Large-scale evaluation of the Positive and Negative Syndrome Scale (PANSS) symptom architecture in schizophrenia

Although the Positive and Negative Syndrome Scale (PANSS) is widely utilized in schizophrenia research, variability in specific item loading exist, hindering reproducibility and generalizability of findings across schizophrenia samples. We aim to establish a common PANSS factor structure from a large multi-ethnic sample and validate it against a meta-analysis of existing PANSS models. Schizophrenia participants (N = 3511) included in the current study were part of the Singapore Translational and Clinical Research Program (STCRP) and the Clinical Antipsychotic Trials for Intervention Effectiveness (CATIE). Exploratory Factor Analysis (EFA) was conducted to identify the factor structure of PANSS and validated with a meta-analysis (N = 16,171) of existing PANSS models. Temporal stability of the PANSS model and generalizability to individuals at ultra-high risk (UHR) of psychosis were evaluated. A five-factor solution best fit the PANSS data. These were the i) Positive, ii) Negative, iii) Cognitive/disorganization, iv) Depression/anxiety and v) Hostility factors. Convergence of PANSS symptom architecture between EFA model and meta-analysis was observed. Modest longitudinal reliability was observed. The schizophrenia derived PANSS factor model fit the UHR population, but not vice versa. We found that two other domains, Social Amotivation (SA) and Diminished Expression (DE), were nested within the negative symptoms factor. Here, we report one of the largest transethnic factorial structures of PANSS symptom domains (N = 19,682). Evidence reported here serves as crucial consolidation of a common PANSS structure that could aid in furthering our understanding of schizophrenia.

The psychometric validity of the Montgomery-Åsberg Depression Rating Scale (MADRS) in recent onset schizophrenia spectrum disorders

Earlier recognition and accurate assessment of depressive symptoms is important to improving outcomes in individuals with recent-onset schizophrenia spectrum disorders (termed SSD hereafter)-regardless of whether positive psychotic symptoms are present or have resolved. The Montgomery-Åsberg Depression Rating Scale (MADRS) is frequently used to assess depressive symptoms in SSD, but no study has examined the psychometric validity of MADRS scores in individuals exclusively with SSD and sub-grouped by those with and without positive psychotic symptoms. This study involved baseline data from the Psychosis Recent Onset GRoningen Survey (PROGR-S). Measures used were: MADRS, depressive and negative subscales of Positive and Negative Syndrome Scale (PANSS_D, PANSS_N), and Schedules for Clinical Assessment in Neuropsychiatry (SCAN). The MADRS total score had sufficient concurrent validity with PANSS_D (evidence by ρ≥0.70), and insufficient divergent validity with PANSS_N (evidenced by ρ ≥0.30), in the full cohort and when sub-grouped by positive psychotic symptoms. In symptom networks, divergent communities comprising either MADRS or PANSS_N items were found, except the MADRS item inability to feel overlapped with PANSS_N items. The most divergent MADRS items were sadness, pessimism, and suicidal thoughts. The MADRS total score had sufficient predictive validity for determining caseness for MDD based on SCAN, but the optimal cut-off differed in those with and without positive psychotic symptoms (MADRS≥18 versus MADRS≥11). The MADRS has sufficient validity for assessing depressive symptoms in SSD. Since scores might depend upon symptoms of SSD, MADRS≥11 and the presence of sadness, pessimism, or suicidal ideation might be the best indicator of MDD in SSD.

Meta-analysis of the positive and Negative Syndrome Scale (PANSS) factor structure

A meta-analysis of the results of 45 factor analyses (n = 22,812) of the Positive and Negative Syndrome Scale (PANSS) was conducted. Meta-analyses of the PANSS was conducted using both a co-occurrence similarity matrix and reproduced correlations. Both methods produced similar results. Five factors (Positive Symptoms, Negative Symptoms, Disorganization, Affect and Resistance) emerged clearly across both analyses. The factors and the items defining them were Positive Symptoms (P1 Delusions, G9 Unusual thought content, P3 Hallucinatory behavior, P6 Suspiciousness and persecution, P5 Grandiosity), Negative Symptoms (N2 Emotional withdrawal, N1 Blunted affect, N4 Passive apathetic social withdrawal, N6 Lack of spontaneity, N3 Poor rapport, G7 Motor retardation, G16 Active social avoidance), Disorganization often termed Cognitive (P2 Conceptual disorganization, G11 Poor attention, N5 Difficulty in abstract thinking, G13 Disturbance of volition, N7 Stereotyped thinking, G5 Mannerisms/posturing, G15 Preoccupation, G10 Disorientation), Affect often termed Depression-Anxiety (G2 Anxiety, G6 Depression, G3 Guilt feelings, G4 Tension, G1 Somatic concern) and a small fifth factor that might be characterized as Resistance or Excitement/Activity (P7 Hostility, G14 Poor impulse control, P4 Excitement, G8 Uncooperativeness). Items G1, G4, G10, P5, G5, G15 may not be core items for the PANSS factors and G12 lack of judgment is not a core item. Results of the PANSS meta-analyses were relatively similar to those for meta-analysis of both the BPRS and BPRS-E all of which contain the original 18 BPRS items. The PANSS is distinguished by a much larger number of items to clearly define and measure Negative Symptoms as well as a sufficient number of items to much more clearly identify a Disorganization factor than the BPRS or BPRS-E.

A cross-national factor analytic comparison of three models of PANSS symptoms in schizophrenia

The 30-item Positive and Negative Syndrome Scale (PANSS) is used worldwide in the assessment of symptom severity in schizophrenia. The present study uses confirmatory factor analysis (CFA) to compare three different factorial models and to evaluate the best-fitting representation of schizophrenia symptom structure on the PANSS across four samples of patients diagnosed with schizophrenia from the US (the CATIE schizophrenia trial), São Paulo, Brazil, and from Beijing and Changsha, China. We examine the goodness of fit of several previously proposed models. The traditional trifactorial model for the PANSS and two five-factor models were evaluated using absolute and incremental indices. Single group CFA found that the five-factor model proposed by NIMH researchers based on an extensive literature review demonstrates the best fit in each of the four samples. This model used 20 of the 30 PANSS items grouped into five factors: positive, negative, disorganized, excited, and depressed symptoms. Subgroups defined by age, gender, nationality, hospitalization status, and severity of illness also did not differ in overall symptom structure as assessed by several standard indices. Our findings suggest that the five factor NIMH model showed the best representation among all four samples from different countries and potentially contrasting cultures.

Reliability, validity and ability to detect change of the PANSS negative symptom factor score in outpatients with schizophrenia on select antipsychotics and with prominent negative or disorganized thought symptoms

The PANSS is a valid instrument assessing schizophrenia symptom severity. Analyses have identified a five-factor solution. The negative symptom factor (NSFS) is robust, having been replicated in multiple analyses. The score has superior content validity versus the negative subscale. Aspects of validity in patients with predominant negative symptoms have yet to be established. The present data are from a Phase IIb study of add-on bitopertin therapy in schizophrenia outpatients with prominent negative or disorganized thought symptoms treated with antipsychotics. Analyses were conducted to evaluate reliability, validity and sensitivity to change. Test-retest screening to baseline was high (ICC=0.93). This was maintained in-study, for patients with no change in CGI negative symptom severity (CGI-S-N). Internal consistency at baseline was adequate (α=0.71) and increased at later assessments. Pearson correlation at baseline showed a good association between NSFS and CGI-S-N (0.63), but not overall CGI-S (0.31). Association with PSP at baseline was moderate (-0.39) and for change at Week eight good (-0.65). NSFS responders (≥20% improvement) at Week eight showed a significant improvement in function. The analyses demonstrated reliability, validity and ability to detect change of the NSFS, in schizophrenia patients with prominent negative or disorganized thought symptoms.

Multilevel ordinal factor analysis of the positive and negative syndrome scale (PANSS)

Clinical assessments of the presence and severity of psychopathology are often collected by health care professionals in mental health services or clinical researchers trained to use semi-structured interviews. Clustering by interviewer or rater needs to be considered when performing psychometric analyses such as factor analysis or item response modelling as non-independence of observations arises in these situations. We apply more suitable multilevel methods to analyse ordinally scored Positive and Negative Syndrome Scale (PANSS) items. Our aim is to highlight the differences in results that occur when the data are analysed using a hierarchically sensitive approach rather than using a traditional (aggregated) analysis. Our sample (n = 507) consisted of patients diagnosed with schizophrenia who participated in a multi-centre randomized control clinical trial, the DIALOG study. Analyses reported and compared include an exploratory factor analysis as well as several recently published multifactor models re-estimated within a confirmatory analysis framework. Our results show that the fit of the model and the parsimony of the exploratory factor analysis (EFA) models indicated by the number of factors necessary to explain the inter-correlation among PANSS items improved significantly when data clustering is taken into account through multilevel analysis. Our modeling results support the pentagonal PANSS model first proposed by White et al. (1997). Copyright © 2014 John Wiley & Sons, Ltd.

A new Integrated Negative Symptom structure of the Positive and Negative Syndrome Scale (PANSS) in schizophrenia using item response analysis

BACKGROUND

Debate persists with regard to how best to categorize the syndromal dimension of negative symptoms in schizophrenia. The aim was to first review published Principle Components Analysis (PCA) of the PANSS, and extract items most frequently included in the negative domain, and secondly, to examine the quality of items using Item Response Theory (IRT) to select items that best represent a measurable dimension (or dimensions) of negative symptoms.

METHODS

First, 22 factor analyses and PCA met were included. Second, using a large dataset (n=7187) of participants in clinical trials with chronic schizophrenia, we extracted items loading on one or more PCA. Third, items not loading with a value of ≥ 0.5, or loading on more than one component with values of ≥ 0.5 were discarded. Fourth, resulting items were included in a non-parametric IRT and retained based on Option Characteristic Curves (OCCs) and Item Characteristic Curves (ICCs).

RESULTS

15 items loaded on a negative domain in at least one study, with Emotional Withdrawal loading on all studies. Non-parametric IRT retained nine items as an Integrated Negative Factor: Emotional Withdrawal, Blunted Affect, Passive/Apathetic Social Withdrawal, Poor Rapport, Lack of Spontaneity/Conversation Flow, Active Social Avoidance, Disturbance of Volition, Stereotyped Thinking and Difficulty in Abstract Thinking.

CONCLUSIONS

This is the first study to use a psychometric IRT process to arrive at a set of negative symptom items. Future steps will include further examination of these nine items in terms of their stability, sensitivity to change, and correlations with functional and cognitive outcomes.

Two subdomains of negative symptoms in psychotic disorders: established and confirmed in two large cohorts

Negative symptoms of schizophrenia are normally grouped into a single category. However, the diversity of such symptoms suggests that they are actually made up of more than one dimension. The DSM-V proposes two negative symptom domains, namely expressive deficits and avolition/asociality. We investigated whether the negative symptoms do indeed have two dimensions. An exploratory factor analysis was carried out based on interviews with the PANSS (664 patients). We restricted our analysis to items that had been described as negative symptoms in previous factor analyses. The symptom structure was then tested for stability by performing a confirmatory factor analysis on PANSS interviews from a separate cohort (2172 patients). Exploratory factor analysis yielded a two-factor structure of negative symptoms. The first factor consisted of PANSS items Flat affect, Poor rapport, Lack of spontaneity, Mannerisms and posturing, Motor retardation, and Avolition. The second factor consisted of Emotional withdrawal, Passive/apathetic social withdrawal, and Active social avoidance. The first factor could be related to expressive deficits, reflecting a loss of initiative, and the second factor to social amotivation, related to community interaction. This factor structure supports the DSM-V classification and may be relevant for pathophysiology and treatment of schizophrenia and other psychotic disorders.

Bipolar depressed patients show both failure to activate and failure to de-activate during performance of a working memory task

BACKGROUND

Bipolar depression has been found to be associated with changes in prefrontal cortex activity during performance of cognitive tasks. However, the role of task-related de-activations has been little investigated.

METHOD

Forty-one bipolar depressed patients and 41 matched normal controls underwent fMRI scanning while performing baseline, 1-back and 2-back versions of the n-back task. Linear models were used to obtain maps of within-group activations and areas of differential activation between the groups.

RESULTS

The bipolar depressed patients showed reduced activation in the dorsolateral prefrontal cortex (DLPFC) bilaterally and several other regions. After controlling for differences in task performance only differences in the DLPFC and cerebellum remained. Left DLPFC activation was inversely correlated with Hamilton and MADRS scores. The patients showed failure to de-activate in the medial prefrontal cortex, an area corresponding to the anterior medial node of the default mode network.

LIMITATIONS

To confirm default mode network dysfunction demonstration of resting-state connectivity abnormalities would also be required. The study was carried out on treated patients, and did not assess for presence of depressive symptoms in the healthy controls.

CONCLUSIONS

Both prefrontal cortical and default mode network dysfunction appear to characterise bipolar depression. The former, but not the latter, is associated with symptom severity.

Cognition and the five-factor model of the positive and negative syndrome scale in schizophrenia

Different exploratory and confirmatory factorial analyses of the Positive and Negative Syndrome Scale (PANSS) have found a number of factors other than the original positive, negative, and general psychopathology. Based on a review of previous studies and using confirmatory factor analyses (CFA), Wallwork et al. (Schizophr Res 2012; 137: 246-250) have recently proposed a consensus five-factor structure of the PANSS. This solution includes a cognitive factor which could be a useful measure of cognition in schizophrenia. Our objectives were 1) to study the psychometric properties (factorial structure and reliability) of this consensus five-factor model of the PANSS, and 2) to study the relationship between executive performance assessed using the Wisconsin Card Sorting Test (WCST) and the proposed PANSS consensus cognitive factor (composed by items P2-N5-G11). This cross-sectional study included a final sample of 201 Spanish outpatients diagnosed with schizophrenia. For our first objective, CFA was performed and Cronbach's alphas of the five factors were calculated; for the second objective, sequential linear regression analyses were used. The results of the CFA showed acceptable fit indices (NNFI=0.94, CFI=0.95, RMSEA=0.08). Cronbach's alphas of the five factors were adequate. Regression analyses showed that this five-factor model of the PANSS explained more of the WCST variance than the classical three-factor model. Moreover, higher cognitive factor scores were associated with worse WCST performance. These results supporting its factorial structure and reliability provide robustness to this consensus PANSS five-factor model, and indicate some usefulness of the cognitive factor in the clinical assessment of schizophrenic patients.

Validated five-factor model of positive and negative syndrome scale for schizophrenia in Chinese population

The Positive and Negative Syndrome Scale (PANSS) is the most widely used instrument to assess the severity of symptoms of schizophrenia. Most studies have showed that PANSS measures five dimensions of symptomatology of schizophrenia. However, few studies have ever investigated the structure of PANSS in Chinese schizophrenia population. We recruited two large independent study samples including 903 and 942 Chinese schizophrenia patients and examined the underlying structure of PANSS. By building a confirmatory factor analysis (CFA) model based on the factor loadings of the exploratory factor analysis (EFA) and by testing the CFA model in an independent validation sample, we found that PANSS scores consisted of five factors, which were positive factor, negative factor, excitement factor, depression factor, and cognitive factor. The items loaded on these factors were similar to the consensus items published in previous studies except for PANSS items P2 conceptual disorganization, P5 grandiosity, N5 abstract thinking, and G11 poor attention. This difference might be due to the influence of culture on clinical presentation of schizophrenia. By elucidating the structure, symptoms of Chinese schizophrenia patients could possibly be deconstructed and investigated in future studies.

Clinical and neuropsychological aspects of non-fatal self-harm in schizophrenia

PURPOSE

To investigate demographic, clinical and neuropsychological aspects of self-harm in schizophrenia and identify which are independently predictive of and therefore the most relevant to clinical intervention.

SUBJECTS AND METHODS

Eighty-seven patients with schizophrenia were interviewed regarding substance misuse, depression, hopelessness, negative/positive symptoms and illness insight. Neuropsychological assessment included premorbid IQ, continuous performance test, cognitive-motor and trait impulsivity. A prospective three-month review of medical records was also undertaken.

RESULTS

Fifty-nine patients (68%) reported past self-harm (including attempted suicide). Those with past self-harm, compared to those without, were significantly more likely to report depression, hopelessness, impulsivity, a family history of self-harm, polysubstance abuse and had higher premorbid IQ. Logistic regression revealed that depression, higher premorbid IQ and polysubstance abuse were independently linked to self-harm. Five participants attempted self-harm during the 3-month prospective follow-up period. These all had a history of past self-harm and were significantly more likely to have been depressed at the initial interview than those who did not go on to self-harm.

DISCUSSION AND CONCLUSIONS

Independent predictors of self-harm in schizophrenia are premorbid IQ and polysubstance abuse. In addition, depression was both independently associated with past self-harm and predictive of self-harm in the follow-up period.

A systematic review of instruments to measure depressive symptoms in patients with schizophrenia

BACKGROUND

Depressive symptoms require accurate recognition and monitoring in clinical practice of patients with schizophrenia. Depression instruments developed for use in depressed patients may not discriminate depressive symptoms from negative psychotic symptoms.

OBJECTIVE

We reviewed depression instruments on their reliability and validity in patients with schizophrenia.

METHODOLOGY

A systematic literature search was carried out in three electronic databases. Psychometric properties were extracted for those instruments of which reliability, divergent, concurrent and predictive validity were reported in one or more publications.

RESULTS

Forty-eight publications described the reliability and validity of six depression instruments in patients with schizophrenia. The only self-report was the Beck Depression Inventory (BDI). The Brief Psychiatric Rating Scale-Depression subscale (BPRS-D), Positive and Negative Syndrome Scale-Depression subscale (PANSS-D), Hamilton Rating Scale for Depression (HAMD), Montgomery Asberg Depression Rating Scale (MADRS) and Calgary Depression Scale for Schizophrenia (CDSS) were clinician rated. All instruments were reliable for the measurement of depressive symptoms in patients with schizophrenia. The CDSS most accurately differentiated depressive symptoms from other symptoms of schizophrenia (divergent validity), correlated well with other depression instruments (concurrent validity), and was least likely to miss cases of depression or misdiagnose depression (predictive validity).

CONCLUSIONS

We would recommend to use the CDSS for the measurement of depressive symptoms in research and in daily clinical practice of patients with schizophrenia. A valid self-report instrument is to be developed for the use in clinical practice.

Searching for a consensus five-factor model of the Positive and Negative Syndrome Scale for schizophrenia

Although the developers of the Positive and Negative Syndrome Scale (PANSS) grouped items into three subscales, factor analyses indicate that a five-factor model better characterizes PANSS data. However, lack of consensus on which model to use limits the comparability of PANSS variables across studies. We counted "votes" from published factor analyses to derive consensus models. One of these combined superior fit in our Caucasian sample (n=458, CFI=.970), and in distinct Japanese sample (n=164, CFI=.964), relative to the original three-subscale model, with a sorting of items into factors that was highly consistent across the studies reviewed.

Sample size requirements for the internal validation of psychiatric scales

The ratio of subjects to variables (N/p), as a rule to calculate the sample size required in internal validity studies on measurement scales, has been recommended without any strict theoretical or empirical basis being provided. The purpose of the present study was to develop a tool to determine sample size for these studies in the field of psychiatry. First, a literature review was carried out to identify the distinctive features of psychiatric scales. Then, two simulation methods were developed to generate data according to: (1) the model for factor structure derived from the literature review and (2) a real dataset. This enabled the study of the quality of solutions obtained from principal component analysis or Exploratory Factor Analysis (EFA) on various sample sizes. Lastly, the influence of sample size on the precision of Cronbach's alpha coefficient was examined. The N/p ratio rule is not upheld by this study: short scales do not allow smaller sample size. As a rule of thumb, if one's aim is to reveal the factor structure, a minimum of 300 subjects is generally acceptable but should be increased when the number of factors within the scale is large, when EFA is used and when the number of items is small.

Sustained attention in the context of emotional processing in patients with schizophrenia

Patients with schizophrenia show dysfunction in sustained attention and facial emotion processing. We investigated the interplay between sustained attention and emotion by presenting emotional faces as background during AX-CPT in patients with schizophrenia. Nineteen schizophrenia patients and 21 healthy control subjects participated. We presented AX-CPT number stimuli superimposed on the nose of background facial expressions (happy, neutral or sad) over three experimental blocks for each emotion. Signal detection sensitivity (A') and reaction time were measured. Patients showed a steeper sensitivity decline when happy faces (compared with sad faces) were presented as background stimuli. By contrast, controls' sensitivity was not affected by the background facial emotion stimuli. Across the emotion conditions, the decline of sensitivity over time was evident in patients, but not in controls. To our knowledge, the present study is the first to explore a change in sustained attention accompanied by simultaneous processing of emotional faces in schizophrenia patients. Our findings suggest that mechanisms underlying continuous performance test (CPT) performance decline over time and facial emotion deficit may interact with each other in patients with schizophrenia.

The effects of psychopathology on subjective experience of side effects of antipsychotics in patients with schizophrenia

This study was conducted to delineate the relationship between self-reported side effects and psychopathology in schizophrenia patients. Patients with schizophrenia completed the Liverpool University Neuroleptic Side Effects Rating Scale for subjective side effects and were evaluated with the Positive and Negative Syndrome Scale for their psychopathology. Based on a series of multiple linear regression analyses, we derived a model accounting for the relationships among the specific domains of psychopathology and red herring (RH) items of the Liverpool University Neuroleptic Side Effects Rating Scale in predicting subjective side effects. The model with anxiety/depressive symptoms and RH serving as mediators between positive symptoms and side effects was found to show good fit. Positive symptoms caused mostly anxiety symptoms and tendency to report RH items, whereby resulting in over-generalized reporting of subjective side effects. However, a large proportion of variance of side effects was explained by RH, which was only partially explained by positive symptoms alone. Therefore, patients with severe levels of positive and anxiety/depressive symptoms may be prone to nocebo-like effects of antipsychotics. Studies that include acute stage patients presenting severe levels of these symptoms should not rely only on the subjective report of side effects but also apply objective measures.

Characterization of affective domains within the nonaffective psychotic disorders

OBJECTIVE

To characterize the affective dimensions of psychopathology in patients with a nonaffective psychosis and to examine their validity against a number of external variables.

METHODS

Five-hundred and thirty-five patients with a lifetime DSM-IV diagnosis of nonaffective psychosis were assessed during the index episode for 22 affective symptoms. These symptoms were factor analyzed and the resulting factor scores were examined for associations with a number of risk factors, illness characteristics, index episode psychopathology and outcome variables.

RESULTS

One-hundred and fifty-six patients (29.1%) met the criteria for a mood disorder during the index episode. Factor analysis of affective symptoms resulted in six factors (mania, core depression, anxiety, retarded depression, dysphoria and lability/mixed) explaining 56% of the variance. Regressions of clinical variables on the six factor scores (p < 0.01 after Bonferroni correction) revealed that mania was related to familial loading to bipolar disorder, shorter duration of the index episode and severity of disorganization symptoms; simple depression was related to suicidal behavior; anxiety was related to psychosocial stressors and reality-distortion symptoms; retarded depression was related to familial loading to major depression, poor premorbid adjustment and negative symptoms; dysphoria was related to violent behavior; lastly, the lability/mixed factor was related to better global functioning, shorter duration of the index episode, better response to treatment and episode polymorphism.

CONCLUSIONS

These results extend the phenomenology of nonaffective psychoses beyond the existing literature to include six affective domains. The validity of each domain is supported by their differential association pattern with illness-related variables.

Stability and relationships between trait or state anhedonia and schizophrenic symptoms in schizophrenia: a 13-year follow-up study

The aim of the present study was to explore the stability of anhedonia and its relationships with schizophrenic symptoms across a 13-year study period. We tested the hypothesis that trait anhedonia, rated by the Physical Anhedonia Scale (PAS), was stable and independent of schizophrenic symptoms across this period, while measures of state anhedonia were not. Sixty schizophrenic subjects were evaluated at two time points, at hospital admission or during an ambulatory psychiatric consultation and 13 years later. Trait anhedonia was assessed using the Chapman Physical Anhedonia Scale, while state anhedonia was assessed with a subscale extracted from the Beck Depression Inventory. The Positive and Negative Syndrome Scale (PANSS) was used to rate schizophrenic symptomatology. Unlike trait anhedonia, state anhedonia decreased significantly over time. Based on results from multiple regressions, negative and depressive dimensions were significant predictors of state anhedonia. Trait anhedonia was not associated with negative symptoms, but was associated with severity of disorganization symptoms at baseline and with our state measure of anhedonia at follow-up. In the current study, state and trait anhedonia were correlated, but depressive symptoms in general were not associated with physical anhedonia. The results indicated that trait anhedonia, in contrast to state anhedonia, had absolute stability, was independent of the negative dimension, as measured by the PANSS, of schizophrenic symptomatology and correlated with specific aspects of depressive anhedonia.

The temporal relationship between symptom change and treatment discontinuation in a pooled analysis of 4 schizophrenia trials

Treatment discontinuation is common in antipsychotic trials for the treatment of schizophrenia and is often associated with symptom worsening. This study assessed the timing and the magnitude of symptom change associated with treatment discontinuation for any cause, and whether improvement in specific symptom domains was predictive of treatment persistence. This post hoc analysis used pooled data from 1627 patients with schizophrenia spectrum disorders who were enrolled in 4 randomized, double-blind antipsychotic comparator trials of 24 to 28 weeks duration. Mean change in the Positive and Negative Syndrome Scale (PANSS) total scores during the last available visit interval were compared for patients who did and did not complete the trial. Improvements in positive, negative, and depression subscores of the PANSS were used to predict trial persistence. A total of 866 patients (53%) discontinued treatment of any cause during the studies. Patients who discontinued treatment early (weeks 0-4) had no significant improvement in mean PANSS total score during the last visit interval, whereas those who discontinued beyond week 4 had significant worsening of mean PANSS total score in the final visit interval. Improvements in either PANSS positive or depression subscores, but not in the PANSS negative subscore, were strongly predictive of study completion. These findings suggest that early failure to establish treatment response and later symptom worsening are associated with treatment discontinuation for any cause. Early improvement in positive or depressive/anxiety symptoms is especially predictive of treatment persistence.

The negative syndrome as a dimension: factor analyses of PANSS in major depressive disorder and organic brain disease compared with negative syndrome structures found in the schizophrenia literature

OBJECTIVE

To explore the concept of the negative syndrome as a dimensional entity that exists in multiple primary diagnoses, and to compare the negative syndrome in nonschizophrenic disorders and schizophrenia.

BACKGROUND

Although initially considered specific to schizophrenia, the negative syndrome has subsequently been described in major depression, stroke, and dementia.

METHOD

We performed an exploratory factor analysis on Positive and Negative Symptom Scale scores of 82 subjects with major depressive disorder and 76 subjects with organic brain disease (dementia or stroke).

RESULTS

The examination of the resultant symptom clusters revealed that the structure of the negative syndrome in major depressive disorder and organic brain disease closely corresponded to that in schizophrenia literature.

CONCLUSIONS

The negative syndrome may be a nosologic entity, which remains fairly consistent across psychotic and nonpsychotic diagnostic categories. Confirmatory studies are merited to determine the degree and strength of the similarity in structure of the negative syndrome in psychotic, affective, and cognitive illness.

Standardized assessment of psychopathology by relatives of mentally disordered patients. Preliminary results of using the positive and negative syndrome scale to compare schizophrenic and affective disorders

BACKGROUND

For optimizing the validity of diagnoses of mental disorders, several sources of information should be used to assess psychopathological symptoms. Among these are relatives of patients with mental illness. The very low number of empirical studies examining the assessment of psychopathology by relatives of adult, nondemented mentally ill patients stands in significant contrast to the clinical importance of this source of information, however.

SAMPLING AND METHODS

Using the Positive and Negative Syndrome Scale (PANSS), researchers asked 163 relatives of patients with the main clinical ICD-10 diagnosis of schizophrenic, recurrent depressive or bipolar disorders to rate the current symptoms of the patients at the time of outpatient community-oriented treatment.

RESULTS

On average, severity of symptoms was rated as absent or minimal, although anxiety, depression and passive/apathetic social as well as emotional withdrawal, motor retardation, poor attention, and disturbance of volition were clearly rated above the PANSS mean total score for all patients. A six-factor structure identified by factor analysis better illustrates the significant differences in the assessments of the three main diagnostic groups than the three established PANSS scales. With the exception of 'problematic social behavior', differences among the diagnostic groups appeared in all factors and were particularly pronounced for 'delusional beliefs' and 'motor impairments'.

CONCLUSIONS

The results of this study showed that the use of standardized instruments such as PANSS for the assessment of psychopathology by relatives is not only practical, but produces adequately reliable results. The use of PANSS for this purpose, however, requires interviewing of relatives by trained experts able to explain technical terms. Because this study did not sufficiently explore the validity of this approach, further research on this specific issue is urgently needed and should, for example, assess the concordance of ratings between professionals and relatives as well as correlation with suitable external criteria.

Validation of the factorial structure of the Positive and Negative Syndrome Scale in use by untrained psychiatrists in routine care

Background. The Positive and Negative Syndrome Scale (PANSS) can be called the standard for the assessment of schizophrenic disorders. It is well-known and routinely used. In scientific studies and clinical practice extensive training of raters in the use of the scale can often not be provided. The question is whether under such conditions psychometric properties of the scale can be guaranteed. Method. In a 2-year drug utilization study on risperidone, 1895 schizophrenic outpatients were assessed by their treating psychiatrists, who were working under conditions of routine care, using a modified version of the Positive and Negative Symptom Scale (PANSS/m). Physicians could not be trained in the use of the scale. The results of these ratings were analysed, comparing means and internal consistency with the original Kay et al. results (Kay et al. The positive and negative syndrome scale (PANSS) for schizophrenia. Schizophr Bull 1987;13:261), and by factor analysis for the total sample and split halves. Results. Means for the positive subscale were similar (6.5 and 6.4, respectively) and means for the negative subscale (11.9 and 8.0, respectively) slightly higher than the original Kay et al. results. Internal consistency of the positive and negative subscales (0.80 and 0.87, and 0.73 and 0.83, respectively) were similar to Kay et al. The same clear factorial solution was found for the total sample and the subsamples. Discussion. Scores for the subscales reflect the predominance of negative symptoms in schizophrenic outpatients. The factorial solution supports the positive and negative subscales of the PANSS. The PANSS/m was easy to use under conditions of routine treatment and is a good and robust scale.