Optimal management for patients with Bipolar II Disorder involves a tailored, individualised treatment approach that is informed, but not dictated, by the clinical trials' literature. It is precisely because of controversy and uncertainty about the nosology of BP II, and its differential diagnosis, that a systematic and thorough assessment of clinical features rightfully precedes treatment, in order to avoid premature diagnostic or therapeutic conclusions. Implementing reasonable and appropriate treatments, with clear rationales, can only occur after the careful evaluation of symptoms and clinical context in light of past history.

Consider the following vignette:

A 28-year-old man with no prior psychiatric history was referred for a second opinion after having presented with complaints of diffuse worry and mood swings. His symptoms began shortly after the break-up of a long-term relationship, which exacerbated feelings of social isolation and anxious ruminations about low self-worth. He denied suicidal thoughts or changes in appetite or sleep. Because of the patient's use of the term ‘mood swings’, he was begun on quetiapine 25 mg/day for a ‘probable diagnosis of Bipolar II Disorder’. Sedated, but without any improvement after 2 weeks, his quetiapine was increased to 50 mg/day and lamotrigine was added at 25 mg/day. Still with no relief two weeks later, the patient returned and inquired whether or not an antidepressant would be worth taking. He was warned by his psychiatrist of the probability that ‘antidepressants cause rapid cycling’ and, instead, oxcarbazepine was added as ‘a mood stabilizer that does not require blood tests’.