The use of antidepressants in the United States increased as much as 400 percent from 1988–1994 through 2005–2008, according to the Centers for Disease and Control Prevention.

For experts, the study exposed two main issues regarding depression in the U.S. The first, is that many physicians may be prescribing antidepressants "like candies" due to the lack of enough mental health providers to treat patients. And second, that patients with depression may be more and more seeking help.

The study released Thursday found that 11 percent of Americans aged 12 and over (more than 1 out of 10) are taking an antidepressant. It also found that two thirds of people with severe depression symptoms are not taking antidepressants at all and 8 percent of Americans without any depressive symptoms take the pills.

The new study was based on responses from 12,000 people during an annual survey in 2005 through 2008.

Antidepressants were the third most common prescription drug taken by Americans of all ages in 2005–2008 and the most frequently used by persons aged 18–44 years, the CDC said.

The study also addressed the period of time the pills are been taken. More than 60 percent of Americans have taken the medications for 2 years or longer, with 14 percent having taken the medication for 10 years or more.

Regarding sex and ethnic groups with greater use, the study published on the CDC's National Center for Health Statistics data brief, noted that females are more likely to take antidepressants than are males with 23 percent of women aged 40–59 taking them.

It also found that non-Hispanic white persons are more likely to take antidepressants: about 14 percent of non-Hispanic white persons take antidepressant medications compared with 4% of non-Hispanic black and 3% of Mexican-American persons.