CHICAGO — A persistent decline in the rate of Americans, especially children, newly diagnosed with depression followed the first federal warning on risks connected with antidepressant drugs, a study suggests.
In 2003, the U.S. Food and Drug Administration first warned about the risk of suicidal thoughts and behaviour in young people taking the drugs.
That action may have helped reverse a five-year trend of rising rates of diagnosis for depression, the researchers found.
The findings, published Monday in the Archives of General Psychiatry, are based on an analysis of eight years of data from nearly 100 managed care plans and more than 55 million patients.
It was already known that antidepressant use among young people had fallen since the drugs began carrying a so-called “black box” warning about risks. But the data showing an extended decline in the level of depression diagnoses are new.
In some cases, untreated depression can be more dangerous than suicidal feelings when starting antidepressants and a spike in teenage suicides in 2004 worried some experts that could be another unintended result of the FDA warnings. Then, teen suicides fell slightly the following year, offering hope that the suicide increase was just a blip.
The new research can’t explain why diagnosis rates have declined, said lead author Anne Libby of the University of Colorado Denver.
Diagnosis rates for anxiety and bipolar disorder, also sometimes treated with antidepressants, also fell.
“It could be that people who have depression aren’t coming forth and getting diagnosed,” Libby said. “It could be that providers are increasingly reluctant to diagnose cases of new mental health problems.”
Libby said the FDA “should reopen its discussion about the boxed warning on antidepressants.”
Only two antidepressants, Lexapro and Prozac, are approved for treating children and adolescents with depression, but doctors can legally prescribe others to young patients “off label.” Prozac, Luvox and Zoloft are approved for pediatric obsessive compulsive disorder, said FDA spokeswoman Sandy Walsh.
Pinning the slumping diagnosis rates on the FDA warning is a leap, said Dr. Peter Lurie of Public Citizen’s Health Research Group, which has warned of antidepressant risks in kids. There could be other explanations.
“It’s possible that the drive toward more diagnosis and treatment had been nearing a point of exhaustion,” Lurie said.
“The data are interesting but the conclusion seems forced.”
Lurie also questioned the authors’ suggestion that the FDA overreacted.
“Is the implication that patients would be better off kept in the dark (about risks)?” he asked.
Dr. Gregory Simon, a psychiatrist and researcher at Group Health Center for Health Studies in Seattle, said the findings are “pretty convincing” evidence that the FDA’s warning had unintended consequences.
“The warning appears to have scared people away from treatment; whether that’s doctors or patients is unclear,” Simon said.
Better follow-up care for patients on antidepressants is sorely needed, he said. Health plans consistently do poorly on quality measures of such follow-up visits, important for avoiding problems when people start taking antidepressants.
The study examined health claims data from July 1999 through June 2007.
For children, the rate of new depression diagnoses rose from 3.3 per 1,000 patients in 1999 to 5.2 in 2004. But by 2007, the rate had fallen to 3.5 per 1,000 patients.
A lesser downward shift was seen for adults, which the authors said could be a spillover effect of the FDA warnings.