Seki T, et al. - Considering the recent work indicating that long noncoding RNAs (lncRNAs) play an important role in chromatin structure, gene expression, and the subsequent manifestation of various biological processes in the central nervous system, researchers examined aberrant expression and function of lncRNAs is linked to the pathophysiology of major depressive disorder (MDD). In the peripheral blood leukocytes of 29 MDD patients and 29 age- and gender-matched healthy controls, expression levels of 83 lncRNAs were assessed using quantitative reverse transcription PCR (RT-qPCR) analysis. As measured by the Hamilton Depression Rating Scale, depression severity was correlated with the expression level of one specific lncRNA (RMRP). A mouse model of depression displayed lower RMRP expression, supporting the observation in MDD patients. Taken together, these data support the potential utility of lower RMRP levels as a biomarker for MDD.