Dimensions of psychosis in patients with bipolar mania as measured by the positive and negative syndrome scale.
ABSTRACT Psychosis is present in 50% or more of patients with bipolar mania and is commonly evaluated in clinical research by means of the Positive and Negative Syndrome Scale (PANSS). The aim of the present analysis was to investigate the psychotic dimensions of bipolar disorder and its contributing symptoms based on a factor analysis of baseline PANSS scores and to compare them with those identified in studies of patients with schizophrenia and bipolar disorder.
Baseline data were analyzed from two 3-week, double-blind, placebo-controlled studies of risperidone monotherapy for acute mania associated with bipolar I disorder (n = 535). Inclusion criteria were a DSM-IV diagnosis of bipolar I disorder with manic features, with or without psychotic features, age > or =18 years, and mean baseline Young Mania Rating Scale scores > or =20. A principal component analysis of the 30 PANSS item scores of the 535 patients with a diagnosis of a manic episode at baseline was conducted.
Five factors were extracted by the analysis: anxiety (13.4% of the variance), negative symptoms (12.3%), depression (10.5%), excitement (10.3%), and positive symptoms (8.7%). Similar factors, in particular the negative, excitement, and positive factors, have been identified in patients with schizophrenia. There was an absence of a cognitive factor supporting the notion that bipolar patients may present fewer cognitive symptoms.
The results of the present analysis and those of other studies indicate similarities in psychotic symptom domains, as measured by the PANSS, in patients with bipolar mania and schizophrenia. Future analyses will address the effects of treatment on the identified factors.
- [Show abstract] [Hide abstract]
ABSTRACT: OBJECTIVE: Both categorical and dimensional methods appear relevant to classifying psychotic disorders; however, there is no clear consensus on the most appropriate categories and dimensions or on the best approach for constructing nosologic criteria that integrate these 2 methods. This review examines the evidence on specific dimensions and categories that would best characterize psychoses. METHOD: Entries in the MEDLINE database between 1980 and 2011 were searched for studies of the dimensional and/or categorical structure of psychosis. Studies were included if samples represented a spectrum of psychotic disorders and dimensions/categories were empirically derived using principal components analysis, factor analysis, or latent class analysis. RESULTS: Most dimensional studies observed 4 or 5 dimensions within psychosis, with positive, negative, disorganization, and affective symptom domains most frequently reported. Substance abuse, anxiety, early onset/developmental, insight, cognition, hostility, and behavioral/social disturbance dimensions appeared in some studies. Categorical studies suggested 3 to 7 major classes within psychosis, including a class similar to Kraepelin's dementia praecox and one or more classes with significant mood components. Only 2 studies compared the relative fit of empirically derived dimensions and categories within the same data set, and each had significant limitations. CONCLUSION: There is relatively consistent evidence on appropriate categories and dimensions for characterizing psychoses. However, the lack of studies directly comparing or combining these approaches provides insufficient evidence for definitive conclusions about their relative merits and integration. The authors provide specific recommendations for designing future studies to identify valid dimensions and/or categories of the psychoses and investigate hybrid approaches to model the structure of the underlying illnesses.Comprehensive psychiatry 06/2012; · 2.08 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Despite the wide use of the Excited Component of the Positive and Negative Syndrome Scale (PANSS-EC) in a clinical setting to assess agitated patients, a validation study to evaluate its psychometric properties was missing. Data from the observational NATURA study were used. This research describes trends in the use of treatments in patients with acute psychotic episodes and agitation seen in emergency departments. Exploratory principal component factor analysis was performed. Spearman's correlation and regression analyses (linear regression model) as well as equipercentile linking of Clinical Global Impression of Severity (CGI-S), Agitation and Calmness Evaluation Scale (ACES) and PANSS-EC items were conducted to examine the scale's diagnostic validity. Furthermore, reliability (Cronbach's alpha) and responsiveness were evaluated. Factor analysis resulted in one factor being retained according to eigenvalue ≥1. At admission, the PANSS-EC and CGI-S were found to be linearly related, with an average increase of 3.4 points (p < 0.001) on the PANSS-EC for each additional CGI-S point. The PANSS-EC and ACES were found to be linearly and inversely related, with an average decrease of 5.5 points (p < 0.001) on the PANSS-EC for each additional point. The equipercentile method shows the poor sensitivity of the ACES scale. Cronbach's alpha was 0.86 and effect size was 1.44. The factorial analyses confirm the unifactorial structure of the PANSS-EC subscale. The PANSS-EC showed a strong linear correlation with rating scales such as CGI-S and ACES. PANSS-EC has also shown an excellent capacity to detect real changes in agitated patients.Health and Quality of Life Outcomes 03/2011; 9:18. · 2.27 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Associations between symptom dimensions and cognition have been mainly studied in non-affective psychosis. The present study investigated whether previously reported associations between cognition and four symptom dimensions (reality distortion, negative symptoms, disorganisation and depression) in non-affective psychosis generalise to a wider spectrum of psychoses. It also extended the research focus to mania, a less studied symptom dimension. Linear and non-linear (quadratic, curvilinear or inverted-U-shaped) associations between cognition and the above five symptom dimensions were examined in a population-based cohort of 166 patients with first-onset psychosis using regression analyses. Negative symptoms showed statistically significant linear associations with IQ and processing speed, and a significant curvilinear association with verbal memory/learning. Significant quadratic associations emerged between mania and processing speed and mania and executive function. The contributions of mania and negative symptoms to processing speed were independent of each other. The findings did not differ between affective and non-affective psychoses, and survived correction for multiple testing. Mania and negative symptoms are associated with distinct patterns of cerebral dysfunction in first-onset psychosis. A novel finding is that mania relates to cognitive performance by a complex response function (inverted-U-shaped relationship). The associations of negative symptoms with cognition include both linear and quadratic elements, suggesting that this dimension is not a unitary concept. These findings cut across affective and non-affective psychoses, suggesting that different diagnostic entities within the psychosis spectrum lie on a neurobiological continuum.Schizophrenia Research 07/2012; 140(1-3):221-31. · 4.59 Impact Factor