[Erik Essen-Möller and the roots of multiaxial classification in psychiatry]

Against the background of the preparation of ICD-11 and DSM-V, the historical roots of a multiaxial diagnostic assessment in psychiatry are reviewed. The principles of such an approach are traced back to the Swedish psychiatrist Erik Essen-Möller who had proposed a distinction between aetiological and descriptive aspects in the classification of mental disorders. Furthermore, he suggested to break down the descriptive classification into the cross-sectional psychopathological picture and the clinical course. Nowadays, a multiaxial assessment is used in diagnostic systems such as DSM-IV. However, these current concepts differ considerably from Essen-Möller's suggestions. A return to the original approach of multiaxial diagnostic assessment comprising the axes "syndromes", "course types" and "aetiology" would be in line with current neurobiological findings and may provide a bridge between the traditional categorical diagnostic approach and dimensional models.