Major depressive disorder (MDD) is one of the most common mood disorders and is a global public health concern because it affects the quality of life of millions of people.

According to the 2010 Global Burden of Disease Study, MDD is a major contributor of disease burden, accounting for 85% of years lost to disability (YLD) within depressive disorders. GlobalData epidemiologists forecast an increase in the 12-month total prevalent cases of MDD in the seven major markets (7MM) of the US, France, Germany, Italy, Spain, the UK and Japan, from 37,157,683 cases in 2015 to 38,142,749 cases in 2025 at an annual growth rate (AGR) of 0.27% (Figure 1).

It is difficult to estimate the true burden of MDD because of the low rates of diagnosis and the social stigma associated with mental health disorders.

In the US and five major European markets (5EU), France, Germany, Italy, Spain and the UK, the 12-month total prevalence for both men and women is similar, at approximately 7%. However, in Japan, prevalence is much lower, at approximately 2.20%.

The lower prevalence of MDD in Japan is likely a reflection of cultural differences and medical practice rather than lower rates of the disease. In Japan, medical practice has considered depression to be primarily a physical condition rather than a combination of both physical and psychological ailments. In addition to disability, MDD is associated with an increased mortality risk by either suicide or simultaneous medical conditions.

Considering the increase in 12-month total prevalent cases in the 7MM projected for 2025 and the extensive disability and mortality burden associated with MDD, it is essential to increase public awareness on the importance of diagnosing and treating MDD, and to eliminate the social stigma associate with the disorder.

The appropriate treatment and diagnosis of MDD are vital because depressive disorders affect not only patients, but also their friends, family members, and employers.