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.

Impact of duration of untreated psychosis in short-term response to treatment and outcome in antipsychotic naïve first-episode psychosis.

AIM: Duration of untreated psychosis (DUP) is one of the few potentially modifiable outcome predictors in psychosis. Previous studies have associated a longer DUP with a poor prognosis, but few of them were performed in countries with low and middle level of income. This study aimed to investigate the DUP in a Brazilian sample of antipsychotic-naïve first-episode psychosis (AN-FEP) patients and its association with clinical characteristics and treatment outcomes in a short-term follow-up. METHODS: One hundred forty-five AN-FEP patients between 16 and 40 years were enrolled and were reassessed 10 weeks after risperidone treatment. We investigated the association between DUP and symptom severity, functionality and response to treatment, using the Positive and Negative Syndrome Scale (PANSS), the Clinical Global Impression-Severity Scale (CGI) and the Global Assessment of Functionality (GAF) scale. DUP was defined as the period between the onset of the first psychotic symptoms and the first effective antipsychotic treatment. For the analysis, we performed multivariate linear regressions. RESULTS: The DUP's median was 61 days. At baseline, we did not find any significant association between DUP and clinical characteristics. After treatment, the longer DUP predicted worse positive and negative symptom dimensions, worse total PANSS, GAF and CGI scores and poorer response to treatment. CONCLUSION: Our results showed that DUP is associated with worse outcomes after short treatment, but it does not modify the baseline clinical profile of the AN-FEP patients. Such results reinforce the need to develop early intervention strategies, reducing DUP.

Cannabis acute use impacts symptoms and functionality in a cohort of antipsychotic naïve First Episode of Psychosis individuals.

INTRODUCTION: Cannabis use increases the risk of developing psychosis, and subjects with psychosis are more likely to use cannabis. However, studies on the influence of cannabis on psychotic dimensions, response to treatment, and functional outcomes showed conflicting results. Such heterogeneity may be due the inclusion of patients who were already under treatment, and lack of specificity in evaluations. We investigated whether cannabis use yields distinct symptom profiles and functionality in a cohort of antipsychotic-naïve patients at first episode of psychosis (FEP). METHODS: This research is part of a prospective cohort study performed in Sao Paulo, Brazil. The baseline assessment was completed by 175 individuals, and 99 of them were reassessed in a ten-week follow up. We investigated the relationship between cannabis exposure variables (acute use, lifetime use and age at first use) and outcomes: symptom dimensions and functioning. RESULTS: Individuals who reported acute use of cannabis had higher excitement symptoms at baseline, higher excitement and positive response rates, but no significant differences at follow-up. Additionally, more days of cannabis use in the last month predicted worse functionality and clinical impression at baseline but not at follow-up. DISCUSSION: The acute use of cannabis influenced the clinical presentation at our FEP baseline assessment, but did not to influence symptoms or functional outcomes at 10-week follow-up. Additionally, acute cannabis users had a better response for excitement and positive symptoms. Higher excitement symptoms at presentation of FEP should raise concerns of possible acute use of cannabis. Longer follow-up times may elucidate whether the effects on functionality would be more evident later in disease development.