Introduction

Bipolar II Disorder is a significant public health problem, and there is a dearth of studies of effective treatment modalities for this specific condition. Literally, the evidence base for most of what we use to treat BP II comes from extrapolation of what we have learned from trials on BP I, unipolar depression, schizophrenia, and even epilepsy. Among several reasons, the two principal ones for this phenomenon are the relative ‘youth’ of the diagnostic category and the absence of a specific regulatory indication for marketing approval. Hence, in the practical absence of solid scientific grounds (El-Mallakh et al., 2006), opinion-based articles like the one by Parker become crucial to assist routine clinical care. I now offer some personal views.

Validity and reliability of the diagnosis of BP II Disorder

There is some evidence supporting BP II as a valid diagnostic category, but its reliability is relatively low (Vieta and Suppes, 2007). This is one of the major sources of both under-diagnosis and misdiagnosis (Akiskal, 2002). Most difficulties come from the frequently egosyntonic, pleasurable and transient nature of hypomania, which makes it very difficult to diagnose retrospectively. If this was a truly mild condition, nobody would care about under-diagnosis and misdiagnosis, but unfortunately, in my view, it is not mild. It only appears so when considered or observed cross-sectionally, but, in the long run it is associated with significant suffering, impairment and suicide (Vieta et al., 1997).