Depression (major depressive disorder or clinical depression) is a common and serious medical illness that negatively affects how you feel, the way you think and how you act. It is a significant contributor to the global burden of disease and affects people in all communities across the world. Depression is estimated to affect 350 million people. The World Mental Health Survey conducted in 17 countries found that on average about 1 in 20 people reported having an episode of depression in the previous year (WHO, 2012).

Depression causes feelings of sadness and/or a loss of interest in activities once enjoyed. It can lead to a variety of emotional and physical problems and can decrease a person’s ability to function at work and at home. To be diagnosed with depression, the symptoms must be present for at least two weeks.

Due to growing rates for depression the primary objective of the study is to determine the efficacy and safety response of Oral Drug ZX37200 in subjects with this diagnosed illness. The results of this study will help to provide further evidence of efficacy and safety of this drug and develop and optymalize the treatment of depression.