Depression may be a feeling of state of dejection, sadness, or unhappiness, which may be brief in duration or a clinical syndrome characterized by persistent sadness, profound discouragement, or despair which persists two weeks or more and is associated with a change from previous functioning.

     It is also characterized by diminished interest in normal activities, mental slowing and poor concentration, insomnia or increased sleep, significant weight loss or gain due to altered eating and activity patterns, psychomotor agitation or retardation, feelings of guilt and worthlessness, decreased energy and libido, and suicidal ideation. ⁽¹⁾⁽²⁾

     Depression is the leading cause of disability worldwide, and is a major contributor to the overall global burden of disease. According to American Psychiatric Association, Depression affects an estimated 1 in 15 adults (6.7%) in any given year. And 1 in 6 people (16.6%) will experience depression at some time in their life. ⁽¹⁾

     There are many first-line medications available for depression but none meet the desirable outcome. Among patients receiving the currently available first-line treatment medications about 30–40% achieve a full remission and another one third respond to therapy but have residual symptoms. ⁽³⁾ Less than half of patients with depression adhere to their antidepressant regimen for the recommended duration, in part because of side-effects such as sleep disturbances, sexual dysfunction, and weight gain. ⁽³⁾  Thus, there is a strong need for improved therapies that have better tolerability and effectiveness.

              Vortioxetine is a new antidepressant for the treatment of depression which was approved on September 2013 by FDA ⁽⁴⁾ and May 2018 by DCGI. ⁽⁵⁾ . The mechanism of action of vortioxetine is thought to be related to a combination of two pharmacological modes of action: direct modulation of receptor activity and inhibition of the 5-HT (serotonin) transporter. ⁽⁶⁾   In vitro, vortioxetine acts as a 5-HT1A receptor agonist, 5-HT1B receptor partial agonist, 5-HT3, 5-HT7, and 5-HT1D receptor antagonist and inhibitor of the 5-HT transporter (SERT) ⁽⁷⁾.  This multimodal pharmacological activity is thought to be responsible for the antidepressant effects and improvement of cognitive function of vortioxetine. Its single dose therapy is also an advantage. As it is a relatively new drug, no clinical trials are available for this drug in Indian population. So this study will help to assess the efficacy and safety of this drug in Indian population.