Abstract

Many efforts have been made to develop coherent and clinically useful categories of depressive illness, especially to facilitate prediction of morbidity and guide treatment-response. They include proposals to resurrect the ancient concept of melancholia, as a form of severe depression with particular symptomatic and proposed psychobiological characteristics. However, modern research is inconsistent in supporting differences between melancholic and nonmelancholic depression. In our recent study of over 3200 patient-subjects with DSM-5 major depressive episodes with/without melancholic characteristics, and matched for illness severity, prevalence of melancholic features was 35.2% with remarkably few clinical and demographic differences between melancholic and nonmelancholic subjects. Also, our systematic review of trials comparing melancholic and nonmelancholic subjects found little difference in responses to antidepressant treatments. These findings indicate that the concept of melancholia may have limited value for clinical prediction and treatment-selection. Overlap of symptoms in melancholic and nonmelancholic depression, based on DSM criteria, may limit distinction of melancholia; alternative definitions can be sought, and psychomotor retardation is a particularly strong differentiating feature. For now, however, melancholia seems best considered a state-dependent depression-type strongly associated with greater symptomatic severity, rather than a distinct syndrome. Its DSM-5 current status as a depression-type specifier seems appropriate, and it may be a logical target for genetic and other biomedical studies.