More than a quarter of people in the US who take anti--depressants have never been diagnosed with any of the conditions the drugs are typically used to treat, according to a study.
As a result, millions could be exposed to side effects from the medicines without proven health benefits, said Jina Pagura, a psychologist and currently a medical student at the University of Manitoba in Canada, and colleagues who worked on the study.
“We cannot be sure that the risks and side effects of anti--depressants are worth the benefit of taking them for people who do not meet criteria for major depression,” Pagura said in an e-mail.
For the study, published in the Journal of Clinical Psychology, Pagura and colleagues tapped into data from the Collaborative Psychiatric Epidemiologic Surveys, which include a nationally representative sample of more than 20,000 US adults interviewed between 2001 and 2003.
Roughly one in ten people told interviewers they had been taking anti-depressants during the previous year, yet a quarter of those people had never been diagnosed with any of the conditions that doctors usually treat with the medications, such as major depression and anxiety disorder.
“These individuals are likely approaching their physicians with concerns that may be related to depression, and could include symptoms like trouble sleeping, poor mood, difficulties in relationships, etc,” Pagura said.
“Although an antidepressant might help with these issues, the problems may also go away on their own with time, or might be more amenable to counseling or psychotherapy.”
According to the National Institute of Mental Health, nearly 15 million people in the US suffer from major depression, and 40 million more have anxiety disorders.
Although the survey did not include all mental illnesses that might have led doctors to prescribe an antidepressant, other experts said the latest findings are not exaggerated.
“Reviews of claims records, which are diagnoses actually given by health care professionals, suggest that only about 50 percent of patients who are prescribed anti-depressants receive a psychiatric diagnosis,” said Mark Olfson, a psychiatrist at Columbia University in New York.
With sales of US$9.9 billion in 2009, up 3 percent from the previous year, anti-depressants rank fourth among prescription drugs in the US, said IMS Health, a company that analyzes the pharmaceutical industry.
While studies have shown the drugs may help some people with depression, they come with a price tag — and not only the US$100 or more that a month’s supply can cost. Some users experience sexual problems or gain weight.
However, it is still not easy to say if anti-depressants are being over-prescribed as a blanket statement, health experts said.
“There are undoubtedly many people being prescribed anti--depressants that may not be effective for them, but there are also millions of Americans suffering from depression who are not being prescribed anti--depressants or are being prescribed them at a suboptimal dose,” said Jeffrey Harman, who lectures in health services at the University of Florida in Gainesville.