Clinical implications of a staging model for bipolar disorders.

A model of staging in the field of bipolar disorder (BD) should offer a means for clinicians to predict response to treatment and more general outcome measures, such as the level of functioning and autonomy. The present staging model emphasizes the assessment of patients in the interepisodic period and includes: latent phase: individuals who present mood and anxiety symptoms and increased risk for developing threshold BD; Stage I--patients with BD who present well established periods of euthymia and absence of overt psychiatric morbidity between episodes; Stage II--patients who present rapid cycling or current axis I or II comorbidities; Stage III--patients who present a clinically relevant pattern of cognitive and functioning deterioration, as well as altered biomarkers; and Stage IV--patients who are unable to live autonomously and present altered brain scans and biomarkers. Such a model implies a longitudinal appraisal of clinical variables, as well as assessment of neurocognition and biomarkers in the interepisodic period. Staging facilitates understanding of the mechanisms underlying progression of the disorder, assists in treatment planning and prognosis and, finally, underscores the imperative for early intervention.