Here are some important facts about depression that will help readers better understand this mental illness:

Fact: Depression is extremely common

Depression is the most common psychiatric condition in the world, affecting more than 150 million people, according to the World Health Organization, or roughly 4% of the global adult population. Depression is more common in the developed world: In the U.S., the incidence of depression is much higher, at around 19% of the adult population (or 48 million people) according to a recent survey by the CDC. (Westly, 2010)

Fact: Women struggle more from depression

Although depression rates are higher among boys in childhood, at around puberty a major shift occurs, and depression becomes much more common among girls than boys. Overall, women are about twice as likely to be impacted by depression. However, whether this discrepancy represents an actual disparity or is merely the result of differences in gender conditioning remains to be seen. Boys are taught from very early on to suppress their emotions and to hide mental pain, which may result in lower rates of diagnosis.

Fact: Depression can be debilitating

Depression is more than a sad mood and a nuisance. It can be extremely debilitating, leaving a person unable to function in their everyday life. In the developed world, depression is the leading cause of medical disability among people between the ages of 15 and 44. (Insel, 2010)