Linden and Vodermaier1 claim that the rate of false-positives with screening for depression is “very acceptable.” Whether a false-positive rate is acceptable depends on the prevalence of disease in the population being screened. Given the prevalence of depression in a typical primary care setting and that about half of patients with depression are typically identified without screening,2 most individuals who screen positive in primary care will not have depression (Figure 1). This is hardly acceptable when one considers the potential harms to patients with false-positive screens and resultant costs to society.2,3 The cost of screening includes assessments, consultations, treatment and follow-up services and is much greater than the cost of administering a questionnaire.4,5 Linden and Vodermaier cite a single randomized controlled trial (RCT) in patients with cancer,6 which did not improve depression scores at follow-up, to support routine screening of depression in primary care. That trial was described as a screening trial, but it did not use depression or distress screening scores to determine which patients would be offered a psychosocial evaluation. Rather, patients received a consultation if they requested one, regardless of their questionnaire results. Referrals for supportive services were potentially recommended to patients following consultation based on many different factors, including, but not limited to, symptoms of depression or anxiety, distress, pain, fatigue, drug or alcohol use, as well as concerns about transportation, parking, and groceries.
Percentage of true- and false-positive screens among patients who screen positive for depression.
Linden and Vodermaier suggest that screening could provide the “social justice of equal access to care.” Access to care would achieve social justice if the benefits of that care outweighed its harms, but this has not been shown for screening for depression. Linden and Vodermaier appear to agree that treatment for depression is most effective when patients have more severe symptoms of depression. Yet most patients who screen positive, but are not otherwise recognized as having depression, will have relatively low depression severity2 (as described in our article).2
No RCT results have shown that patients who are screened for depression have better depression outcomes than patients who are not screened for depression, and there have been many negative trials.2 Thus, we re-assert that the available evidence does not support screening for depression as routine health policy.