4.7 percent of U.S. population suffers from persistent depression or anxiety disorders

Dec 3 2008

Though effective treatments are available for individuals suffering from chronic depression and anxiety, very little is known about how often these treatments are used or how prevalent these conditions are among the nation's general population.

But in a first-of-its-kind study, UCLA researchers have developed estimates for both the prevalence of chronic psychiatric illness in the general population and how often individuals suffering from such illnesses receive appropriate treatment.

In the study, published in the December issue of the peer-reviewed journal Psychiatric Services and currently available online, researchers found that approximately 4.7 percent of the nation's population suffers from persistent depression or anxiety disorders, with a minority of those afflicted receiving adequate medication or counseling.

"From a policy perspective, this study indicates that we have to do much better in terms of helping people in the population and clinicians in primary care," said lead author Dr. Alexander S. Young, a UCLA professor of psychiatry and director of health services for the Department of Veterans Affairs Desert Pacific Mental Illness Research, Education and Clinical Center (MIRECC). "We need to understand that psychiatric disorders are treatable with psychotherapy and/or medication. Patients would benefit if we improved linkages between primary care and specialty mental health care so that patients are referred and accept referrals to mental health specialists, especially when they are chronically ill.

"Also, we have to improve insurance arrangements so that they encourage more intensive treatment in people who remain ill," he said.

The study was based on data from Healthcare for Communities, a nationally representative household survey of adults in the United States. The researchers analyzed responses from 1,642 adults with major depression or anxiety disorders. These surveys, conducted in 1997 and 1998, with follow-ups approximately two-and-a-half years later, assessed diagnosis, quality of life, treatment satisfaction, medical conditions, suicidal thoughts, insurance, and the use of medications and counseling.

At follow-up, the researchers found that 59 percent of the individuals no longer met the criteria for having a psychiatric disorder. But to their surprise, they found that among those who remained ill, there were only modest increases in medication use and no statistically significant increase in the use of counseling for their disorders - measures that are known to significantly improve outcomes, especially when used in combination. Among this subgroup:

• 87 percent had a chronic, co-morbid medical disorder.
• In the prior year, 88 percent had seen a primary care practitioner, but only 22 percent had consulted a mental health specialist.
• In the two-and-a-half years between baseline and follow-up, use of medication rose from 21 percent to 29 percent, and use of counseling fell from 23 percent to 19 percent.
• Only 12 percent with persistent illness were getting both medication and counseling (the appropriate treatment in this situation).
• 51 percent had suicidal thoughts at follow-up.
• Men and those with less education received less treatment.

"Persistent depressive and anxiety disorders are remarkably common in the U.S. population and are associated with substantial morbidity. There are significant problems with the quality of care received by this population, and these problems persist over time," the researchers concluded. "In the population with persistent depressive and anxiety disorders, increasing the rate of appropriate care from its current low level could result in substantial improvement in individuals' lives."