Staging bipolar disorder: clinical, biochemical, and functional correlates

Grande I, Magalh~aes PV, Chendo I, Stertz L, Panizutti B, Colpo GD,Rosa AR, Gama CS, Kapczinski F, Vieta E. Staging bipolar disorder:clinical, biochemical, and functional correlates.Objective: There are several models of staging in bipolar disorder (BD),but none has been validated. The aims of this study were to empiricallyinvestigate clinical variables that may be useful to classify patients inclusters according to stage and study the association with biomarkers asbiological validators.Method: This was a historical cohort study. Patients (n = 115)diagnosed with BD and not in an acute episode and first-degreerelatives of patients diagnosed with BD (n = 25) were recruited.Sociodemographic, clinical, and functional data were collected. Serumcytokines, brain-derived neurotrophic factor, and biomarkers of lipidand protein oxidation were assessed. Cluster analysis was carried out tobuild a model of staging, and logistic regression was conducted to studyassociations between the model and biomarkers.Results: Cluster analysis divided the sample into two equitable groups,denominated early and late stage, with empirical cutoffs for theFunctioning Assessment Short Test score, number of episodes, age atonset of the disorder, and time elapsed since first episode. In the logisticregression, IL-6 was associated with late stage (P = 0.029).Conclusion: This study supports that clinical, functional, andbiochemical variables may help to define a classification of staging inBD.