As common as depression is, most people with depression in the U.S. are not being treated for it. That's the conclusion of a national survey that looked at over 46,000 adults. It found that less than a third of the people who screen positive for depression received treatment in the last year.

Researchers from Columbia University Medical Center (CUMC) and the University of Pennsylvania analyzed data from a national survey focusing on the treatment of depression. The survey, conducted in 2012 and 2013, gathered information on depressive symptoms, serious psychological distress, whether people were treated with antidepressants and psychotherapy, the types of health care professionals providing treatment, and other variables including age, gender, race, education, marital status, income and health insurance.

There's still a substantial mismatch between those who are depressed and those who are being treated for it.

Depression was nearly five times more common among low income individuals than in people with high income. It was also common among adults who were separated, divorced or widowed, had public health insurance or had less than a high school education.

Those who were most likely to receive treatment included publicly-insured individuals and separated/divorced/widowed people, whereas those least likely to get treated were the uninsured, racial and ethnic minorities and men.

Most people (70.1%) who were being treated for depression did not screen positive for it on the two-question screen. This might not seem that surprising — antidepressant prescriptions became so widespread in the 1990s that some people began calling the United States Prozac Nation. Many of these prescriptions were not for depression. Nowadays, even some pets take Prozac. Yet the finding indicates that's there's still a substantial mismatch between those who are depressed and those who are being treated for it.

In other words, healthcare providers need to pay more attention to how severe a person's depression is and then treat based on each patient's needs. “These patterns suggest that more needs to be done to ensure that depression care is neither too intensive nor insufficient for each patient. Although screening tools provide only a rough index of depression severity, increasing their use might nevertheless help align depression care with each patient's needs,” said Mark Olfson, MD, MPH, professor of psychiatry at CUMC and senior author of the report.

The study concludes that: “Although access to depression care has expanded in recent years, critical treatment gaps persist, especially for racial/ethnic minorities, low income individuals, less educated adults and uninsured people.”

The study appears in JAMA Internal Medicine.