CHAPEL HILL, N.C. - Symptoms of major depression are most likely to persist in people who also have an anxiety disorder, according to a study headed by a psychiatrist at the University of North Carolina at Chapel Hill.
The new findings can help primary care doctors target patients needing more aggressive treatment for depression, says Dr. Bradley Gaynes, assistant professor of psychiatry and director of the Psychiatric Consultation Service at UNC-CH.
Gaynes points out that primary care doctors - typically family physicians and internists - provide nearly half of the outpatient care for people in the United States diagnosed with depression. "And they provide at least as many anti-depressant prescriptions annually compared to psychiatrists," he says.
"Major depression accounts for somewhere between 5 percent and 13 percent of the primary care population, making it more common than high blood pressure, and the problems associated with it match or exceed that associated with most of the common chronic medical conditions," he says.
Depression among primary care patients generally is not as severe as in psychiatric settings, and a certain proportion of depressed patients in primary care get better whether or not they receive the appropriate treatment for their psychiatric problem. Still, as Gaynes explains, primary physicians are in a difficult position regarding the problem largely due to the time crunch per patient associated with managed care.
"They average on the order of 10 minutes per visit and must deal with a large number of medical issues per patient. So it becomes a challenge to decide which of their depressed patients do they need to worry about," he says. "Namely, in which patients might symptoms of major depression persist at least one year to potentially cause serious difficulties?"
In a report published June 15 in General Hospital Psychiatry, Gaynes and co-authors from Duke University Medical Center and the National Institute of Mental Health decided to focus on "coexisting anxiety disorder" as a key indicator of that risk.
According to the study team, several reasons account for their choice. First, anxiety disorders have been identified as a predictor of persistent depressive illness among patient in mental health settings. Second, anxiety disorders commonly coexist with major depression in primary care settings -- in 28-66 percent of patients, studies show. Also, depression among people with coexisting anxiety disorders, such as panic disorder, tends to worsen.
This 12-month study involved 85 Duke family practice patients for whom diagnostic interviews indicated major depression. Of these, 43 had a coexisting anxiety disorder (38 with social phobia) and 42 depression only. There were no substantial demographic differences between the groups, nor were there any differences in severity of medical illness, severity of depressive illness, or number of workdays lost due to disability.
All patients were followed-up at three-month intervals. "The risk for persistent depression at 12 months was 44 percent greater in those with coexisting anxiety," the authors state. And in those without an anxiety disorder, only 57 percent had a depressive illness at the one-year follow-up.
Gaynes says the findings point to a course of action in the primary care setting. "Patients who present with a depressive disorder should also be screened for anxiety symptoms. If a coexisting anxiety disorder is present, those patients are the primary care group that physicians need to worry about because their depressive illness is more likely to persist."
He also says that having depression coexistent with anxiety can alter the form of treatment. These patients may be much more susceptible to the anxiety-related effects of the newer antidepressant medications, the serotonin selective re-uptake inhibitors, or SSRIs, such as Prozac.
"One of the primary side effects of SSRIs is they tend to agitate and make people anxious. It could lead depressed people with coexisting anxiety to stop taking the medication. This group would benefit from a lower initial dose of SSRIs and may need a more gradual increase in their dose," he says. "One of the greatest problems in treating depression in primary care clinics is noncompliance within the first three months. They just stop taking the medication because it's not working or making them feel worse."
In addition, the presence of coexisting anxiety might suggest the need for "adjunctive treatment" in addition to the anti-depressant. "Patients may also need anti-anxiety medication or they might benefit from a referral to a psychologist or psychiatrist for some form of psychotherapy," Gaynes says.
Note to media:
Dr. Bradley N. Gaynes can be reached at 919-966-8028; email:
bgaynes@css.unc.edu.
UNC-CH School of Medicine media contact is Lynn Wooten,
919-966-6046 or email LWooten@unch.unc.edu.