Current research is mainly focused on ‘classical episodic’ forms of bipolar disorder (I and II). Despite its historical roots, cyclothymia is still neglected among the bipolar spectrum disorders. Contrary to DSM definition, based on the recurrence of low-grade episodes, cyclothymia is better defined as an exaggeration of cyclothymic temperament: early onset, complex temperament structure, high mood instability and reactivity, and rapid switching. Current epidemiological and clinical research has demonstrated the high prevalence and the validity of cyclothymia as a distinct form of bipolarity. In this article, the authors discuss their own clinical research and expertise on the understanding and medical management of cyclothymia. This is the beginning of challenging work concerning psychoeducation, clinical, phamacological and genetic research.