Are rating scales for bipolar disorders fit for purpose?

The DSM-5 definition of bipolar disorder elevates increased activity or energy as a cardinal symptom (alongside mood changes) for mania and hypomania ('hypo/mania'). The ICD-10 likewise requires increases in activity and energy (alongside mood) for hypo/mania, as well as decreases for bipolar depression. Using bipolar disorder as an example, we propose that, when diagnostic criteria are revised, instruments used to measure clinical course and treatment response may need revisiting. Here, we highlight that the 'gold-standard' symptom rating scales for hypo/mania and depression were developed in an era when abnormalities of mood were viewed as the cardinal symptom of bipolar disorder. We contend that archetypal measures fail to give proportionate weighting to activity or energy, undermining their utility in monitoring bipolar disorder and treatment response in clinical and research practice.Declarations of interestJ.S. and G.M. are members of mMARCH, (Motor Activity Research Consortium for Health), which is led by Dr Kathleen Merikangas, National Institute for Mental Health. J.S. reports being a visiting professor at Diderot University, the Norwegian University of Science and Technology, Swinburne University of Technology and The University of Sydney; receiving grant funding from the UK Medical Research Council and from the UK Research for Patient Benefit programme; and receiving a personal fee from Janssen-Cilag for a non-promotional talk on sleep problems.