Depression has become a major public health concern all around the world. Depressive disorders were ranked fourth in terms of global burden by The Global Burden of Disease Project in 1990. Depression is predicted to affect 10.4% of the world's population. The expense of treating depressive illnesses has risen in tandem with the prevalence of these conditions. The National Institute of Mental Health (NIMH) estimated the yearly cost of treating depressive disorders in the United States to be $US26 billion in 2000. The accessibility and effectiveness of these medicines, in addition to the rising costs of treatment, limit their impact. Only 55 percent of patients with a depressive condition are receiving therapy, and only 32% of those who are receiving treatment report relief from their symptoms. According to more recent study, only 27.5 percent of depressive patients achieve remission after receiving initial pharmaceutical treatment. Between 17.6 percent and 24.8 percent of those who did not respond to first treatment responded to a medication switch, and 30 percent responded to boosted medication.
