Thing one and thing two¹: What 'Doctors use' to doctor you?

This perspective piece is a detailed analysis of the critique by Gordon Parker of the mood disorders clinical practice guidelines (MDcpg²⁰²⁰), in which he claims that bipolar II disorder has been 'banished' despite its formal status in current taxonomies. In this article, I defend the reasoning used by the Committee to adopt a dimensional model for describing and managing mood disorders, in particular bipolar disorder. I also robustly contend the many erroneous inferences made by him in his Viewpoint regarding management recommendations within the MDcpg²⁰²⁰ and demonstrate that there is no valid justification for subtyping bipolar disorder - especially in the manner proposed by the Diagnostic and Statistical Manual of Mental Disorders, 5th edition. Thus, I argue that it was appropriate for the MDcpg²⁰²⁰ Committee to pursue an alternative model to the usual subtyping of bipolar disorder into 'thing one' and 'thing two' and conclude that the now clearly redundant model of Bipolar II should be altogether removed from our lexicon and clinical practice. Indeed, it is time to develop new and alternative models for defining bipolar disorder and among these a dimensional model should be given consideration.