Background: Depression is a debilitating disease that is affecting a growing
number of patients, both physically and mentally. In addition to mood changes, depression
results in cognitive impairment. Although depression studies have been going on for decades,
the underlying mechanism still remains unclear. MicroRNAs (miRNAs), a type of
small non-coding RNAs, predominantly control the expression of their target mRNAs to exert
their functions. Some evidences have revealed the importance of miRNAs in the mechanism
of depression,however, these studies are still in their infancy. Alterations in brain regions,
synaptic plasticity, hypothalamic-pituitary-adrenal (HPA) axis, changes in the levels
of serotonin and glucocorticoids, together with stress response have been proven to be involved
in depression. These alterations can influence cognition, learning and memory, with
recent evidences demonstrating the involvement of miRNAs in several aspects of stress response,
neural plasticity and neurogenesis as well as pathogenesis of depression.
Objective: In light of these theories of depression, this review was aimed at elucidating the
role of miRNAs in the underlying mechanisms of depression resulting in cognitive, learning
and memory impairments.
Method/Results: Both PubMed and Scopus databases were employed in scouring for research
reports pertaining to this area of study. A total of 180 articles were obtained from
these two databases.
Conclusion: With the probing of classical theories of depression as well as the connection
between miRNAs and depression, more studies,nevertheless, are needed to ascertain the full
mechanism of depression along with its resultant cognitive, learning and memory impediments.