Commentary

In 1996, the US Preventive Services Task Force (USPSTF) concluded that insufficient evidence existed to recommend routine screening for depression in adult primary care practice. Pignone et al updated the USPSTF systematic review by incorporating studies to August 2001. They concluded that screening and feedback increase the recognition of depression by a factor of 2 to 3 (absolute increase 10% to 47%). Some studies found an increase in the rate of treatment of depression in the intervention group, while others found no difference. Similar variability occurred in the clinical outcomes, notably the prevalence of depression at follow up. When the studies were pooled by meta-analysis, the intervention groups had a 10% to 13% reduction in relative risk and a 7% to 9% absolute decrease in the prevalence of persistent depression. This led the USPSTF to recommend screening for depression, citing good evidence that screening is beneficial, particularly when combined with effective follow up and treatment.

Why did the USPSTF recommendations change from those of 6 years ago? They did so primarily because of several larger studies released since the previous report, which account for more than half of the “weight” in the weighted meta-analysis.

What should we conclude from these studies? 2 conclusions seem warranted. Firstly, screening for depression with feedback of results is important, because it dramatically increases the recognition of depression. However, studies that relied on feedback, even when combined with treatment advice, generally did not have an effect on clinical outcomes. Therefore, the second conclusion is that the system of care needs to be reorganised¹ to support the screening and recognition, which can be accomplished through such methods as quality improvement. One approach to support that has worked well is the use of a care manager for depression.² Such system change is not only more likely to be beneficial, it is also more likely to endure over time.