Depressive disorders affect approximately 18.8 million American adults or about 9.5% of the U.S. population age 18 and older in a given year. This includes major depressive disorder, dysthymic disorder, and bipolar disorder.

According to the World Health Organization

• Depression is common, affecting about 121 million people worldwide.
• Depression is among the leading causes of disability worldwide.
• Depression can be reliably diagnosed and treated in primary care.
• Fewer than 25 % of those affected have access to effective treatments