Longitudinal invariance of the positive and negative syndrome scale negative dimension in antipsychotic naïve first-episode schizophrenia.

AIM: Construct stability over time is required for reliable inference, but evidence regarding the longitudinal invariance of negative symptoms is still limited. Thus, we examined the longitudinal invariance of the negative dimension using the positive and negative syndrome scale (PANSS) in an antipsychotic-naïve first-episode schizophrenia sample at baseline and after 10 weeks. METHODS: Our study was conducted at a specialized early intervention service. PANSS ratings were analysed for 138 patients, and two different models were specified and tested: a unidimensional and a two-correlated factor solution. RESULTS: The unidimensional model fulfilled criteria for longitudinal invariance, whilst the two-correlated did not. CONCLUSION: Our study provides support for the PANSS negative unidimensional model use to evaluate negative symptoms' longitudinal change following first-episode schizophrenia.

What is the Best Latent Structure of Negative Symptoms in Schizophrenia? A Systematic Review.

BACKGROUND: Determining the best latent structure of negative symptoms in schizophrenia could benefit assessment tools, neurobiological research, and targeted interventions. However, no review systematically evaluated studies that assessed and validated latent models of negative symptoms. OBJECTIVE: To identify and evaluate existing latent structure models in the literature of negative symptoms and to determine the best model. METHOD: Systematic search of MEDLINE, EMBASE, and Scopus on July 19, 2020, for confirmatory factor analysis models of negative symptoms in patients with schizophrenia. The available evidence was assessed through 2 sets of criteria: (1) study design quality-based on negative symptoms assessment and modeling strategy and (2) psychometric quality and model fit-based on fit indices and factor definition quality. RESULTS: In total, 22 studies (n = 17 086) from 9 countries were included. Studies differed greatly regarding symptom scales, setting, and sample size (range = 86-6889). Dimensional models included 2-6 factors (median = 4). Twelve studies evaluated competing models and adopted appropriate instruments to assess the latent structure of negative symptoms. The 5-factor and hierarchical models outperformed unitary, 2-factor, and 3-factor models on all direct comparisons, and most of the analyses derived from the Brief Negative Symptom Scale. Considering the quality criteria proposed, 5-factor and hierarchical models achieved excellent fit in just one study. CONCLUSIONS: Our review points out that the 5-factor and hierarchical models represent the best latent structure of negative symptoms, but the immaturity of the relevant current literature may affect the robustness of this conclusion. Future studies should address current limitations regarding psychometric properties and also address biological and clinical validity to refine available models.

Evaluation of Ongoing Participation of People with Schizophrenia in a Mutual Support Group as a Complementary Intervention to Outpatient Psychiatric Treatment.

This study aims to evaluate a group of people with schizophrenia undergoing outpatient treatment and who participate in a mutual support intervention, compared to another group of people with the same diagnosis, but attending only the usual outpatient treatment. This is a prospective study, with two measurements between six months. The mutual support group was initially composed of 16 people and the treatment as usual group was composed of 15 people. Clinical (medication adherence and functioning) and Recovery (hope, well-being, recovery and internalized stigma) outcomes were assessed. Nonparametric tests were used to verify differences in measurements between groups and between two moments. A higher level of internalized stigma and a decrease in the adherence to drug treatment in the treatment as usual group were verified. When comparing the pre-post difference between groups, there was a greater increase in adherence to drug treatment in the mutual support group. Our data point to more favorable results in the mutual support group, showing that ongoing participation in these groups is an important tool for the recovery process and for the treatment itself.