Background: Depression or Major depressive disorder (MDD) is a prolonged condition
of sadness. MDD is the most common mental disorder that affects more than 264 million people
worldwide. According to the monoamine hypothesis, serotonin (5-hydroxy tryptamine, 5-HT), dopamine
(DA) and norepinephrine (NE) are the major neurotransmitters (NTs) involved in depression.
Methods: The methodology adopted for writing this review article is essentially based on the secondary
literature search through a systematic literature review. This review mainly focussed on
the role of 5-HT3 receptor antagonists (5-HT3RA) in depression and comorbid disorders like anxiety.
Results: Out of three major NTs mentioned above, serotonin has a predominant role in the pathophysiology
of depression. The serotonin type-3 receptors (5-HT3R) are well renowned to be expressed
in the central nervous system (CNS) in regions which have significance in the vomiting reflex,
perception of pain, the reward system, cognition, depression and anxiety control. 5-HT3R are
the receptors of serotonergic family that belong to ligand-gated ion channel. 5-HT3RA inhibit the
binding of serotonin to postsynaptic 5-HT3R and increases its availability to other receptors like 5-
HT1A, 1B and 1D as well as 5-HT2 receptors and produces anti-depressant-like effect. 5-HT3RA also
have an important role in mood and stress disorders. Some of the studies have shown the effectiveness
of these agents in stress disorder.
Conclusion: The present article focussed on the role of 5-HT3R and their antagonists in the treatment
of depression and anxiety. Further studies are warranted to prove their efficacy with respect
to other standard anti-depressants.