Depression is a persistent and serious psychiatric illness, affecting over 120 million people worldwide. 13%~20% people have the experience of depressive disorder and the lifetime prevalence rate is 6.1%~9.5%. Moreover, 35.5%~50.3% of seriously depressed patients in developed countries had no appropriate treatment and this rate in lessdeveloped countries has rocketed to 76.3%~85.4%.Nowadays, depression has been one of the most important risk factors for lifetime suicide attempts and the population attributable risk proportion has been approximately 28%. According to the World Health Organization (WHO) statistics, depression would be the largest leading cause ended up to death worldwide by 2030.Both the suffering from depressed patients and the premature deaths by suicide resulted from depression lead to a significant social burden. The primary ways to reduce these burdens are the promotion of health systems efficiency and cost-effective treatment strategies.
The discovery of tricyclic antidepressants (TCAs) as well as monoamine oxidase inhibitors (MAOIs) in the 1950s gave impetus on research into developing new antidepressant medications with a better safety profile and less side effects. Then, the selective 5-HT reuptake inhibitors (SSRIs) were considered as more effective antidepressants. More recently, 5-HT-norepinephrine reuptake inhibitors (SNRIs) have been widely used in clinic. Though the treatment of depression is efficacious, these antidepressant drugs frequently produce side effects and are generally expensive.

References

1.Guo-jiang Penga et al. Current Neuropharmacology, 2015, 13, 514-523.