The potential of microRNAs as putative biomarkers in major depressive disorder and suicidal behavior

Major affective disorder are common and disabling conditions linked to significant psychosocial impairment as well as negative outcome (e.g., suicidal behaviors) . According to a molecular perspective, major depressive disorder and suicidal behavior have been associated with structural and synaptic plasticity disturbances. Small non-coding RNAs, such as microRNAs (miRNAs), may play a significant role in the translational regulation of the synapse. This comprehensive overview is aimed to carefully review the preclinical and clinical literature results regarding the involvement of miRNAs in the pathophysiology and pharmacotherapy of major psychiatric conditions . MiRNAs may act as gene expression regulators critically affecting brain development. The alteration of some intracellular mechanisms together with impaired assembly, localization, and translational regulation of specific RNA binding proteins may affect important functions such as learning and memory contributing to the pathophysiology of major depressive disorder and suicidal behavior. Based on the main findings, most of the miRNAs which have been identified to date are expressed in human brain, where they regulate prominent neurobiological processes, such as neurogenesis and neuroplasticity. The main implications of the present findings are critically discussed.