Questions in Psychiatry (QuiP): Is staging bipolar disorder possible? If so, where to begin?

The prospect of staging psychiatric disorders has been a source of ongoing controversy since the idea was first proposed in the early 1990s, based on the staging models used for cancer. More recently, several staging models have been proposed for bipolar disorder; however, as yet there is no consensus as to which model (or composite) is best, and there is no substantive evidence in support of any one of the models. The fundamental problem is that, unlike cancer, the pathophysiology of psychiatric disorders such as bipolar disorder is essentially unknown. The illness has many neurobiological underpinnings, but whether these are truly causal and if so how they lead to the illness, remains a mystery. As a consequence, there is no way of predicting when the illness will emerge and what trajectory it will take. Its response to treatment and prognosis is equally unpredictable, and therefore, models attempting to stage the disorder on the basis of clinical markers have limited utility. This is especially so, because the clinical presentation of bipolar disorder is particularly complex as it often occurs in the context of comorbidities, which further obscure the clinical picture. Therefore, in this QuiP, we provide insights as to why current methods of staging bipolar disorder are hamstrung and propose a way forward that may yield meaningful insights.