Clinical Question

To what extent does universal screening for depression in primary care improve the lives of patients?

Bottom Line

There is considerable uncertainty, which is reflected in the disparate guidelines, about whether screening for depression is helpful to patients (rather than a way to label them as being depressed or not). Most of the positive scores on the Patient Health Questionnaire-9 tool will be falsely positive (77%) for patients screened in primary care and many of those who have mild depression will not benefit from treatment. (Level of Evidence = 5)

Synopsis

Universal screening of primary care patients for depression is not recommended by the U.K.’s National Institute for Health and Care Excellence or the Canadian Task Force, but is recommended by the U.S. Preventive Services Task Force if adequate systems for follow-up are in place. The authors used systematic reviews from these groups as the basis for their analysis, augmenting them with a search for randomized trials that evaluated the benefits associated with screening. The available studies used various screening tools and outcomes, the latter ranging from general mental health to depression symptoms to meeting diagnostic criteria for major or minor depression. The screening was designed to cast a wide net and emphasized not missing anyone. This approach resulted in a higher rate of false positives. The authors then provided an estimate: assuming 5% of patients screened in primary care will have undiagnosed depression at any visit, 18 patients will screen positive (a score of at least 10 on the Patient Health Questionnaire-9), but 77% of these results will be falsely positive (i.e., only four of those 18 patients will have depression). Only a small proportion of these patients will have moderate to severe depression that necessitates drug treatment.

Study design: Systematic review

Funding source: Self-funded or unfunded

Setting: Other

Reference: Thombs BD, Markham S, Rice DB, et al. Does depression screening in primary care improve mental health outcomes? BMJ. 2021;374:n1661.

Editor’s Note: Dr. Shaughnessy is an assistant medical editor for AFP.