Cyclothymia, a circular mood disorder.

Ewald Hecker (1843-1909) was a collaborator of Karl Ludwig Kahlbaum (1828-1899). Both worked outside the university and public mental institutions of Germany. By meticulously observing clinical signs and illness-course, they laid the groundwork for modern descriptive psychiatry. Their clinical approach influenced Kraepelin and continues to dominate psychiatric classification. Hecker popularized several of Kahlbaum's syndromal concepts, including hebephrenia. Another was cyclothymia, a relatively benigh form of manic-depressive illness, introduced by Kahlbaum, in 1882. It included depressive (dysthymia), hypomanic (hyperthymia), and mixed hypomanic-depressive phases. The Kahlbaum-Hecker syndrome of cyclothymia survives in DSM-IV bipolar II disorder and cyclothymia. An annotated English translation of Hecker's 1898 paper is provided, with historical notes on Hecker and the significance of his work.