This article aims to propose a mathematically legitimate and externally validated subclassification of chronic affective disorders. Three subtypes emerged from the cluster analysis of the symptom data of 40 patients with chronic affective disorder that had been present without remission for more than 2 years; the subtypes were then validated by psychosocial variables. The first cluster, a predominantly male group with young onset, is characterized by past history of psychotic features and is named psychotic subtype. The second cluster, a predominantly female group with late onset, is tentatively called late-onset female subtype. The third cluster has the youngest onset and the longest duration, and is characterized by early object loss and high neuroticism score: depressive personality subtype.