From 1996 to 2005, twice as many Americans went on antidepressants, according to a new study reported on by Reuters.

Researchers said about 6 percent—or 13 million people—were prescribed antidepressant medication in 1996. In 2005, this number jumped to more than 10 percent or 27 million people.

“Significant increases in antidepressant use were evident across all sociodemographic groups examined, except African Americans,” said Mark Olfson, MD, of Columbia University and Steven Marcus, PhD, of the University of Pennsylvania in Philadelphia.

The researchers noted that in addition to more U.S. citizens being treated with antidepressant pills, those in treatment are acquiring more prescriptions for these meds.

Last year, more than 164 million prescriptions were written for antidepressants, adding up to $9.6 billion in U.S. sales, according to IMS Health, an information provider to the pharmaceutical industry.

Researchers attribute the trend to cost and social acceptance. It’s cheaper for people to pop a pill than visit a therapist, they said, and most people find it socially acceptable to take antidepressants.

Another health professional, however, expressed concern about the study’s findings.

“Antidepressants are only moderately effective on population level,” said Eric Caine, MD, of the University of New York at Rochester, who was not involved in the research.

Caine noted that several studies indicate depression therapy is as effective if not more so than drug treatment.

Read RH’s “Take Off the Mask” for more about how depression affects the black community.