A Comparison of the Familiality of Chronic Depression in Recurrent Early-onset Depression Pedigrees Using Different Definitions of Chronicity

Background The study of chronicity in the course of major depression has been complicated by varying definitions of this illness feature. Because familial clustering is one component of diagnostic validity we compared family clustering of chronicity as defined in the DSM-IV to that of chronicity determined by an assessment of lifetime course of depressive illness.