A rise in prescribing of antidepressants by doctors who are not psychiatrists, often for uses other than depression/anxiety, has helped build what is now a massive market, according to an 11-year health policy study just published in Health Affairs. Such prescribing could signal a need for formulary or other changes, the study authors conclude.
According to IMS Health, sales of antidepressants in the United States alone surpassed $11 billion in 2010.
Antidepressants are now the third most commonly prescribed drug class in this country, Ramin Mojtabai, M.D., Ph.D., of the Johns Hopkins Bloomberg School of Public Health, notes in the article. Appearing in the Aug. 3 issue of the policy journal, the article was coauthored by Columbia University psychiatrist Dr. Mark Olfson, whose research was funded by the Agency for Healthcare Policy and Research as well as Eli Lilly.
Four out of five physicians prescribing antidepressants are not psychiatrists, and antidepressants are commonly prescribed by primary care doctors, the authors noted (Health Aff. 2011;30:1434-42 [doi:10.1377/hlthaff.2010.1024]). In addition, they found the drugs are increasingly being given for nonpsychiatric uses.
Between 1996 and 2007, the percentage of doctor visits during which antidepressants were prescribed but no psychiatric diagnosis was noted increased from 59.5% to 72.7%, according to the study, which was based on the National Ambulatory Medical Care Surveys conducted by the Centers for Disease Control and Prevention. The surveys canvas doctors for one randomly chosen week per year. Response rates in the study period ranged from 62.9% to 77.1%.
In the study period, the number of doctor visits that resulted in a psychiatric disorder diagnosis increased only slightly to moderately among nonpsychiatrists. Overall, the data show antidepressants were prescribed in 9.3% of visits to primary care doctors and 3.6% of visits to other nonpsychiatrists.
The authors noted that antidepressants have been demonstrated to be clinically effective for only a limited number of psychiatric conditions: major depressive disorder, chronic depression, some anxiety disorders, and a few other well-defined conditions.
But antidepressant use is becoming concentrated among people with less severe and poorly defined medical conditions, according to the study: "Associations between antidepressant prescriptions and problems such as tiredness, nonspecific pain, smoking problems, headaches, abnormal sensations and premenstrual tension suggest that antidepressants are being prescribed to treat these medical complaints."
Forays Into Additional Indications. During the study period, many antidepressant brands added additional, nonpsychiatric indications, so not all nonpsychiatric uses are off label. Those approvals have often launched with extensive advertising. Lilly’s Prozac (fluoxetine) was approved under the trade name Sarafem for premenstrual dysphoric disorder in 2000, Pfizer’s Zoloft (sertraline) added the PMDD claim in 2001, and GlaxoSmithKline’s Paxil CR (paroxetine) followed in 2003.
GlaxoSmithKline’s Wellbutrin (bupropion) was approved under the trade name Zyban as an aid to smoking cessation in 1997.
Pain and related indications have also been added for many of the branded products; while some approvals have come outside the study period, off-label use preceded the FDA imprimatur. Lilly’s Cymbalta (duloxetine) was approved for diabetic neuropathic pain in 2004 and chronic musculoskeletal pain in 2010. A fibromyalgia indication was cleared in 2008. Other antidepressants have been studied in fibromyalgia and are used off label.
Prescribing Trends Are ‘Worrisome.’ "We do not yet have proof that inappropriate use of antidepressants is increasing," the study authors say, "but the change in prescribing trends is worrisome."
They think the trends suggest that primary care physicians may overestimate the effectiveness of antidepressants in treating mild conditions, and that better communication is needed between primary care doctors and psychiatrists.
In the past, off-label prescribing of antidepressants has been tough to nail down, partly because patients may be prescribed a drug without a diagnosis code to protect privacy and avoid the stigma of a psychiatric disorder. Reimbursement patterns have also encouraged use of more general medical codes.
Identities of providers and patients in the National Ambulatory Medical Care Surveys are protected, however, and consequently providers had little motivation to deliberately withhold psychiatric diagnoses from researchers, the authors stated.
As part of the study, the researchers noted the presence of common conditions such as diabetes and heart disease, which have been linked to depression.
"Although such problems are often not the primary reason for a medical visit, a patient’s complaints about them may nevertheless prompt a provider to prescribe an antidepressant," the article stated.
Demographic data collected in the study suggest that those getting a prescription with no psychiatric diagnosis were more likely to be over 50, female, and covered by public health insurance. They were also more likely to have general indications of medical illness, such as diabetes or heart disease, and nonspecific pain or abnormal sensations.