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Abstract
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The revised US Preventive Services Task Force (USPSTF) guidelines1,2 advise screening for major depressive symptoms in primary care (B statement), as in past iterations. The evidence base on this point is compelling. Major depressive disorder itself contributes massively to morbidity and mortality worldwide, and for almost every other illness, the presence of depression can make the management of that illness more difficult. The depression screening instruments have repeatedly been shown to have good sensitivity for identifying depressive episodes.3 Depression treatments, whether pharmacologic or psychosocial, have repeatedly demonstrated efficacy compared with placebo treatment.4 The effect sizes of such treatments may be smaller than we might hope, but notwithstanding some popular misconceptions to the contrary, their effect sizes are clinically significant.
But while physicians are advised to screen for depression, the guidelines1,2 explicitly do not advise for or against screening for the most feared complication of depression, suicide risk (I statement). In general, guidelines in other disorders would advise for screening for the disorder as well as its major complications. What accounts for this apparent inconsistency?
The lack of a recommendation is not attributable to a lack of potential impact: suicide represents a leading cause of death in the US.5 The screening measures themselves are valid, insofar as they estimate future risk, although as the USPSTF report notes,1,2 the positive predictive value is very low. But the USPSTF conclusions1,2 rest primarily on a paucity of evidence that interventions to prevent suicide are efficacious--primarily drawn from studies of self-harm in borderline personality disorder. The report emphasizes that, absent sufficient data, it cannot advise for or against screening for suicidality.1,2
But if there are effective treatments for depression, and depression is a risk factor for suicide, it should follow that treating depression reduces suicide risk. This association has been profoundly difficult to demonstrate. The notable exception is among adults aged 65 years and older, for whom an analysis of clinical trials data by the US Food and Drug Administration (FDA) found that antidepressants were associated with a significant diminution in risk of suicidal thoughts and behaviors compared with placebo.
There are a multitude of reasons that diagnosis and treatment of depression is important, many outlined in the USPSTF report.1,2 Unfortunately, there remains a lack of clinical trials demonstrating antisuicide efficacy for most antidepressant interventions. Notably, emerging short-term studies do support benefit for acute interventions, such as ketamine infusion, but these interventions remain inaccessible to most patients, as public and private insurance generally will not yet pay for them.
In fact, perhaps the most important impact of the USPSTF guidelines1,2 is to underscore the mismatch between the amount of discussion of suicidality and the amount of data. In light of the indisputable public health impact, it is worth considering why we lack such studies.
Language: en |