Conceptualizing the later stage of bipolar disorder: Descriptive analyses from the ORBIT trial.

Latent phenomenological features relevant to individuals in the later stage of BD were identified. Two clusters of individuals in later stage BD differ based on these features as well as course of illness, suggesting that there are distinct subgroups of individuals in the later stage of BD, distinguishable based on current phenomenology and illness history. However, findings are exploratory and therefore require confirmation before they can be applied clinically.