September 12, 2011

Antidepressant RXs on rise in those with no psychiatric diagnosis

Americans are no strangers to antidepressants. During the last 20 years the use of antidepressants has grown significantly, making them one of the most costly, and the third most commonly prescribed class of, medications in the United States. According to the Centers for Disease Control and Prevention, from 2005 to 2008 nearly 8.9 percent of the U.S. population had at least one prescription in this drug class during any given month.

A new study led by researchers at the Johns Hopkins Bloomberg School of Public Health examines national trends in antidepressant prescribing and finds that much of this growth was driven by a substantial increase in antidepressant prescriptions by nonpsychiatrist providers without any accompanying psychiatric diagnosis. The results are featured in the August issue of Health Affairs.

“We’ve seen a marked increase in antidepressant use among individuals with no psychiatric diagnosis. Nearly four out of every five antidepressant prescriptions are written by nonpsychiatrist providers,” said Ramin Mojtabai, lead author of the study and an associate professor in the Bloomberg School’s Department of Mental Health. “Between 1996 and 2007, the number of visits where individuals were prescribed antidepressants with no psychiatric diagnoses increased from 59.5 percent to 72.7 percent, and the share of providers who prescribed antidepressants without a concurrent psychiatric diagnosis increased from 30 percent of all nonpsychiatrist physicians in 1996 to 55.4 percent in 2007.”

Using data from the 1996–2007 National Ambulatory Medical Care Surveys, researchers reviewed a national sample of office-based physician visits by patients ages 18 years and older during a one-week period. They conducted two sets of logistic regression analyses, comparing antidepressant visits lacking psychiatric diagnoses with antidepressant visits including psychiatric diagnoses and with visits lacking both prescriptions for antidepressants and psychiatric diagnoses. In addition, Mojtabai and colleagues assessed physician practice-level trends in antidepressant visits without psychiatric diagnosis and found that in the general medicine practice, antidepressant use was concentrated among people with less severe and poorly defined mental health conditions.

An earlier study led by Mojtabai and published in the Journal of Affective Disorders examined the impact of expansion of antidepressant use on the prevalence and characteristics of depression and suicidal ideations. That study found that antidepressant use significantly reduced the prevalence of more severe depression and suicidal ideations among individuals with severe depressive episodes. The findings led researchers to recommend that antidepressants be prescribed primarily to individuals with severe depression or a confirmed psychiatric diagnosis.

“With nonspecialists playing a growing role in the pharmacological treatment of common mental disorders, practice patterns of these providers are becoming increasingly relevant for mental health policy,” Mojtabai said. “To the extent that antidepressants are being prescribed for uses not supported by clinical evidence, there may be a need to improve providers’ prescribing practices, revamp drug formularies or undertake broad reforms of the health care system that will increase communication between primary care providers and mental health specialists.”

“The Proportion of Antidepressants Prescribed Without a Psychiatric Diagnosis Is Growing” was written by Mojtabai and Mark Olfson and was supported in part by the Agency for Healthcare Research and Quality.

“The Public Health Impact of Antidepressants: An Instrumental Variable Analysis” was written by Mojtabai.