The World Health Organization reports that more than 350 million people suffer from depression globally.
The announcement was meant to coincide with World Mental Health Day on Wednesday, reports AFP.
Dr Shekhar Saxena, head of the WHO's mental health and substance abuse department, told the AFP: "It is not a disease of developed countries, it is a global phenomenon. It's present in both genders and in rich and poor populations."
Saxena said that 50 percent more women suffer depression symptoms than men, while post-natal depression affected 20% of mothers and 10% of all young mothers in the developed world.
The World Health Organization defines depression as a "sustained feeling of sadness for two weeks or more" which interferes with "work, school or home."