Despite the hardships of
major depressive disorder (MDD),
biomarkers for the diagnosis and pharmacological management of this condition are lacking.
MicroRNAs are epigenetic mechanisms that could provide promising MDD
biomarkers. Our aim was to summarize the findings and provide validation for the selection and use of specific
microRNAs as
biomarkers in the diagnosis and treatment of MDD. A systematic review was conducted using the PubMed/Medline, Cochrane, PsycINFO, Embase, and LILACS databases from March 2022 to November 2023, with clusters of terms based on "
microRNA" and "
antidepressant". Studies involving human subjects, animal models, and cell cultures were included, whereas those that evaluated
herbal medicines, non-pharmacological
therapies, or epigenetic mechanisms other than
miRNA were excluded. The review revealed differences in the expression of various
microRNAs when considering the time of assessment (before or after
antidepressant treatment) and the population studied. However, due to the heterogeneity of the
microRNAs investigated, the limited size of the samples, and the wide variety of
antidepressants used, few conclusions could be made. Despite the observed heterogeneity, the following
microRNAs were determined to be important factors in MDD and the
antidepressant response: mir-1202, mir-135, mir-124, and mir-16. The findings indicate the potential for the use of
microRNAs as
biomarkers for the diagnosis and treatment of MDD; however, more homogeneous studies are needed.