To the Editor In JAMA Psychiatry, Pine and Leibenluft1 highlighted the importance of biomarkers in elucidating mechanisms. However, there is an issue regarding the nomenclature of biomarkers that clouds the field in that the term biomarker is typically used as an interchangeable umbrella term for a diversity of biological and clinical phenomena. The fields would be assisted in this regard by greater systematized precision in the use of the term biomarker.