Potential harm, but no demonstrated benefit from depression screening in primary care

Brett Thombs

September 19, 2011 – The Canadian Task Force on Preventive Health Care recommends routine screening for depression during primary care visits when systems are available for coordination of assessment and treatment. An article by an international panel of experts, published in the October issue of the Canadian Medical Association Journal, argues that there is no evidence that screening benefits patients and that, moreover, implementation of the practice would further burden an already financially-strapped health care system. The authors urged the Task Force to reconsider its position when it reviews the recommendation this year.

“Screening may seem like an obvious solution to an important problem, but there is no evidence that it works and there are many reasons to think it might not work, even under the best of circumstances,” said the article’s lead author, Dr. Brett Thombs of the Lady Davis Institute at the Jewish General Hospital and Associate Professor of Psychiatry at McGill University in Montreal. “We estimate that as many as five out of six patients identified as depressed through screening will probably not have depression.”

The authors conclude that no clinical trial has demonstrated that patients screened for depression have better mental health outcomes than patients who are not screened. They note that screening is only effective if it can successfully identify depressed patients who are not already identified and treated by their doctors, and if it can minimize the number of people incorrectly labelled as possibly depressed.

“Current prescriptions of anti-depressant medications exceed the number of patients with depression, leaving little room for finding additional people who would benefit from treatment,” added Thombs. “Anti-depressants are effective for people with serious depression, but they don’t work well for those with only mild symptoms of depression.”

In 2010, the National Institute of Clinical Excellence in the United Kingdom, noting the lack of evidence that depression screening benefited patients, did not recommend routine screening in primary care settings. Instead, it suggested that physicians be alert to symptoms of depression and respond accordingly when there is a specific concern.

“Inappropriate use of screening and inappropriate treatment for people who don’t need it is a bad idea. It may waste resources that are needed to treat those who are seriously ill and really should be getting care,” said John Ioannidis, Director of the Stanford Prevention Research Center, who is a co-author of the paper.

The Canadian Institutes of Health Research provided funding that supported work on this article. In addition to Thombs, members of the expert panel who contributed to the review included James C. Coyne, PhD, of the University of Pennsylvania, USA, and the University of Groningen, the Netherlands; Pim Cuijpers, PhD, of VU-University, Amsterdam the Netherlands; Peter de Jonge, PhD, of the University of Groningen, the Netherlands; Simon Gilbody, DPhil, FRCPsych, of the University of York, the UK; John P. A. Ioannidis, MD, DSc, of Stanford University, USA; Blair T. Johnson, PhD, of the University of Connecticut, USA; Scott B. Patten, MD, PhD, of the University of Calgary; Erick H. Turner, MD, of the Oregon Health and Science University and Portland Veterans Affairs Medical Center, USA; and Roy C. Ziegelstein, MD, of Johns Hopkins University, USA.


Tod Hoffman
Research Communications Officer
Lady Davis Institute for Medical Research
514-340-8222, ext. 8661

For further information about the Lady Davis Institute, visit www.ladydavis.ca.

For further information about the Jewish General Hospital, visit www.jgh.ca.