Validity of specific subscales of the positive and negative symptom scales in older schizophrenia outpatients

The potential effect of metformin on cognitive and other symptom dimensions in patients with schizophrenia and antipsychotic-induced weight gain: a systematic review, meta-analysis, and meta-regression

Introduction

Metformin has shown good efficacy in the management of antipsychotic-induced metabolic syndrome (MetS) in patients with schizophrenia or schizoaffective disorders. Its ability to induce antidepressant behavioural effects and improve cognitive functions has also been investigated: yet information has not been systematized. The aim of this study was therefore to investigate the effects of metformin on cognitive and other symptom dimension in schizophrenic patients treated with antipsychotics through a systematic review and meta-analysis.

Methods

We searched PubMed, ClinicalTrials.Gov, Embase, PsycINFO, and WHO ICTRP database up to February 2022, Randomised Controlled Trials (RCT) evaluating patients diagnosed with schizophrenia and related disorders, who were treated with metformin as add-on therapy to antipsychotics for the treatment of weight gain and in which changes in psychiatric symptoms and cognitive functions were evaluated.

Results

A total of 19 RCTs met the inclusion criteria. Meta-analysis was performed on 12 eligible studies. We found a positive trend after 24 weeks of treatment in schizophrenic patients with stable conditions [SMD (95%CI) = -0.40 (-0.82;0.01), OR (95%CI) = 0.5 (-2.4;3.4)]. Better performance was detected in the Brief Assessment of Cognition in Schizophrenia and Positive and Negative Syndrome Scale (PANSS) with low heterogeneity among studies. One study reported changes in BACS-verbal memory subdomain in favour of placebo [MD (95%CI) = -16.03 (-23.65;8.42)]. Gastrointestinal disorders, xerostomia, and extrapyramidal syndrome were the most reported adverse effects. Psychiatric adverse events were also described: in particular, symptoms attributable to a relapse of schizophrenia.

Conclusion

Some degree of efficacy was found for Metformin in improving cognitive and other symptom dimensions in patients with Schizophrenia. Given the clinical relevance of this potential pharmacological effect, longer specific studies using adequate psychometric scales are strongly recommended. Likewise, how metformin acts in this context needs to be evaluated in order to enhance its efficacy or find more efficacious drugs.

Using dimensionality-reduction techniques to understand the organization of psychotic symptoms in persistent psychotic illness and first episode psychosis

Psychotic disorders are highly heterogeneous. Understanding relationships between symptoms will be relevant to their underlying pathophysiology. We apply dimensionality-reduction methods across two unique samples to characterize the patterns of symptom organization. We analyzed publicly-available data from 153 participants diagnosed with schizophrenia or schizoaffective disorder (fBIRN Data Repository and the Consortium for Neuropsychiatric Phenomics), as well as 636 first-episode psychosis (FEP) participants from the Prevention and Early Intervention Program for Psychosis (PEPP-Montreal). In all participants, the Scale for the Assessment of Positive Symptoms (SAPS) and Scale for the Assessment of Negative Symptoms (SANS) were collected. Multidimensional scaling (MDS) combined with cluster analysis was applied to SAPS and SANS scores across these two groups of participants. MDS revealed relationships between items of SAPS and SANS. Our application of cluster analysis to these results identified: 1 cluster of disorganization symptoms, 2 clusters of hallucinations/delusions, and 2 SANS clusters (asocial and apathy, speech and affect). Those reality distortion items which were furthest from auditory hallucinations had very weak to no relationship with hallucination severity. Despite being at an earlier stage of illness, symptoms in FEP presentations were similarly organized. While hallucinations and delusions commonly co-occur, we found that their specific themes and content sometimes travel together and sometimes do not. This has important implications, not only for treatment, but also for research-particularly efforts to understand the neurocomputational and pathophysiological mechanism underlying delusions and hallucinations.

Are the available apathy measures reliable and valid? A review of the psychometric evidence

OBJECTIVE

Apathy is highly prevalent among neuropsychiatric populations and is associated with greater morbidity and worse functional outcomes. Despite this, it remains understudied and poorly understood, primarily due to lack of consensus definition and clear diagnostic criteria for apathy. Without a gold standard for defining and measuring apathy, the availability of empirically sound measures is imperative. This paper provides a psychometric review of the most commonly used apathy measures and provides recommendations for use and further research.

METHODS

Pertinent literature databases were searched to identify all available assessment tools for apathy in adults aged 18 and older. Evidence of the reliability and validity of the scales were examined. Alternate variations of scales (e.g., non-English versions) were also evaluated if the validating articles were written in English.

RESULTS

Fifteen apathy scales or subscales were examined. The most psychometrically robust measures for assessing apathy across any disease population appear to be the Apathy Evaluation Scale and the apathy subscale of the Neuropsychiatric Inventory based on the criteria set in this review. For assessment in specific populations, the Dementia Apathy Interview and Rating for patients with Alzheimer's dementia, the Positive and Negative Symptom Scale for schizophrenia populations, and the Frontal System Behavior Scale for patients with frontotemporal deficits are reliable and valid measures.

CONCLUSION

Clinicians and researchers have numerous apathy scales for use in broad and disease-specific neuropsychiatric populations. Our understanding of apathy would be advanced by research that helps build a consensus as to the definition and diagnosis of apathy and further refine the psychometric properties of all apathy assessment tools.

Clinical characterization of late- and very late-onset first psychotic episode in psychiatric inpatients

OBJECTIVES

The goals of this study were to investigate the prevalence and initial symptoms of the late-onset schizophrenia (LOS: >40 years) and very-late-onset schizophrenia-like psychosis (VLOSLP: >60 years) nosological groups proposed by the International Late-Onset Schizophrenia Group.

DESIGN

This was a retrospective, cross-sectional, chart review study.

SETTING

The study was conducted at Centre Hospitalier Robert-Giffard (CHRG), Quebec City, Canada.

PATIENTS

The medical records of inpatients from the CHRG who presented with psychotic symptoms were analyzed.

MEASUREMENTS

Positive and negative symptoms were scored using the SAPS and SANS. Groups' symptoms were compared using chi(2), Fisher's exact tests, t tests, and exact Mann-Whitney tests. An exact conditional logistic regression analysis was performed to determine which clinical characteristics were the most predictive of the groups' classification.

RESULTS

Among the 1,767 unique, first-admission medical records reviewed, 23 (1.3%) inpatients developed their first psychotic symptoms at the age of 40-59 years old (LOS), and 13 (0.7%) at the age of 60 years and above (VLOSLP). LOS patients were more apathetic and presented more abnormal psychomotor activity than the VLOSLP. Persecutory delusions, auditory hallucinations, inappropriate social behavior, formal thought disorders and anhedonia were frequent in the two groups. A logistic regression model including psychomotor abnormalities was statistically relevant to predict the belonging to LOS group.

CONCLUSION

LOS and VLOSLP are rare. Abnormal psychomotor activity can properly differentiate VLOSLP and LOS. The nosological model proposed by the International Late-Onset Schizophrenia Group is at least partially supported by the present data.

Persistent negative symptoms in schizophrenia: an overview

Persistent negative symptoms represent an alternative approach for assessing negative symptoms in the context of clinical trials. Persistent negative symptoms are designed to capture those symptoms that lead to functional impairment but are currently understudied and for which there are no currently available effective treatments. Persistent negative symptoms differ from the 2 most commonly used approaches: primary, enduring negative symptoms or deficit symptoms and negative symptoms broadly defined to include negative symptoms, regardless of their etiology or duration. In contrast to deficit symptoms, persistent negative symptoms may include secondary negative symptoms. However, in contrast to negative symptoms broadly defined, the secondary negative symptoms included in the assessment of persistent negative symptoms only include those that have failed to respond to usual treatments for secondary negative symptoms. In consequence, the presence of persistent negative symptoms identifies a patient population with clinically relevant symptomatology, which is larger than the one with the deficit syndrome but less heterogeneous than that captured through the use of a nonrestrictive definition of negative symptoms. This may facilitate the selection of subjects for inclusion into research and efforts to develop new pharmacological treatments and enhance our understanding of a relevant clinical problem. Ultimately, the investigation of the different entities characterized by negative symptoms, such as persistent negative symptoms, and the enhanced understanding of their biological and clinical characteristics may help to unravel the psychopathological and biological heterogeneity of schizophrenia.

The five symptom dimensions and depression in schizophrenia

The aim of this study was to investigate the relationship between the five-factor model of psychopathology and depression in schizophrenia. Symptoms were rated using the Positive and Negative Syndrome Scale (PANSS) and the Montgomery and Asberg Depression Rating Scale (MADRS) in 105 chronic patients with schizophrenia. Principal-component analysis (PCA) produced a five-factor solution for the PANSS (psychomotor poverty, disorganisation, reality distortion, excitement, and depression), and a two-factor solution for the MADRS (psychological and behavioural depression). The PANSS depression factor was highly associated with the MADRS psychological depression factor but not with MADRS behavioural depression. By contrast, the PANSS excitement factor showed a strong positive correlation with the behavioural depression factor but not with psychological depression. These MADRS factors were not associated significantly with the core PANSS factors, including psychomotor poverty. It is suggested that depression exists as an independent domain, differentiated from negative symptoms, in the structure of schizophrenia symptomatology.

Assessing disturbed thinking and cognition using the Ego Impairment Index in older schizophrenia patients: paranoid vs. nonparanoid distinction

OBJECTIVE

We compared thought-disturbance via the Rorschach-derived Ego Impairment Index (EII) between DSM-IV paranoid vs. nonparanoid (undifferentiated and disorganized) subtypes of older schizophrenia patients.

METHODS

44 DSM-IV medically stable outpatients with schizophrenia (27 paranoid, 17 nonparanoid) and 45 normal comparison participants aged 45-100 years were assessed using the EII, a Rorschach-derived cognitive-based measure of disturbed thinking. Group differences on the EII and the relation of this measure to key demographic and clinical variables were examined.

RESULTS

Nonparanoid schizophrenia patients demonstrated significantly greater impairment on the EII than their paranoid counterparts. The EII performance of paranoid patients was similar to normal comparison participants. Furthermore, the paranoid patients displayed better premorbid intellectual functioning, less negative symptoms, and better global cognitive performance than nonparanoid patients. Finally, greater impairment on the EII was correlated with poor performance on a global measure of cognitive ability.

CONCLUSIONS

The present findings substantiate previous work suggesting that nonparanoid patients have a form of the illness characterized by worse premorbid functioning and greater disturbed thinking and cognition than their paranoid counterparts.