Primary care doctors should not screen their patients for depression

KEYWORDS:

• Depression
• screening
• United States Preventive Services Task Force
• mental health
• primary care

1. Introduction

Major depression is a potentially disabling condition that is present in 5–10% of patients in primary care and as many as 10–20% of patients with certain chronic medical conditions [1]. Thus, there is little disagreement that health-care providers in primary care settings need to be vigilant to the possibility that patients may be depressed and that mental health assessment is a crucial part of standard care. Mental health assessment involves being alert and assessing for mental health problems by using clinical skills to observe, asking thoughtful questions about a patient’s mood and other relevant aspects of her or his experience, diagnosing as appropriate, and providing quality management when needed.

Recently, the United States Preventive Services Task Force (USPSTF) recommended that primary health-care providers should screen all adolescents and adults, including pregnant women, for depression as part of routine clinical care [2,3]. Depression screening, as described by the USPSTF, would involve the routine use of self-report depression symptom questionnaires with prespecified cutoff scores, administered to all patients, regardless of the perceived risk that they may have depression, to identify those who may have depression, but who have not sought treatment and have not otherwise been recognized as depressed by health-care providers or via self-report [1,4,5]. Thus, screening would occur in presumably asymptomatic patients who are not recognized as having symptoms. Identification of possible cases of depression would be based on screening test scores above a cutoff threshold.

Primary health-care providers should make every effort to provide the best possible mental health assessment and care. However, there are at least four important reasons why they should disregard the USPSTF recommendation to screen for depression. First, screening is premised on the idea that detection is unlikely or impossible as part of routine clinical care and that early identification of a progressive disease during an asymptomatic phase makes it possible to intervene in order to prevent that progression (e.g. some cancers). The presence of depression may not be readily apparent to some patients or clinicians. Symptoms of depression, however, are not hidden as they often are in early-stage infectious diseases or cancer. Rather, depression is a constellation of symptoms that are experienced by patients and that can be identified in many cases by patients or as part of usual clinical care without the use of a screening test. Second, there is no evidence from well-conducted randomized controlled trials (RCTs) that screening would improve mental health outcomes. Third, screening would unnecessarily harm some patients. Fourth, screening would consume valuable health-care resources that would then not be available for activities that would likely benefit patients.

2. Screening is premised on the idea that detection is unlikely or impossible in routine clinical care and that tests are needed to identify preclinical progressive disease

Health screening that has been demonstrated to successfully improve health outcomes has traditionally involved using medical tests to identify apparently healthy people with early stage, asymptomatic disease in order to increase the likelihood of effective intervention and improve future health. Enthusiasm for the idea of screening has, in recent years, resulted in an expansion of the scope of screening itself. In addition to screening to attempt to identify preclinical indicators of disease, the term ‘screening’ has been applied to using self-report patient questionnaires to ‘screen’ for currently experienced health problems or symptom-based syndromes, such as alcohol misuse, illicit substance use, intimate partner violence, and developmental delays in young children. Not surprisingly, using screening in this manner is controversial; the USPSTF has made recommendations to screen with questionnaires for depression, alcohol misuse, and intimate partner violence, whereas the Canadian Task Force on Preventive Health Care (CTFPHC), the United Kingdom National Screening Committee (UKNSC), or both have recommended against each of these practices [6]. A recent study found that none of the recommendations for questionnaire-based screening made by the USPSTF included evidence from well-conducted RCTs that screening improved health outcomes. On the other hand, there were six trials of questionnaire-based screening programs with negative or equivocal results [6].

3. There is no direct evidence that depression screening improves mental health outcomes

Many patients who meet criteria for depression are not recognized in current medical practice. Better training of providers in the diagnosis of depression, as well as increased sensitivity to the many manifestations of depression, would almost certainly improve case identification. While depression screening would also increase the number of patients who are diagnosed, screening identifies many individuals who do not have the condition. Some of this latter group may then be exposed to the harms of labeling and treatment without any chance of benefit. Thus, recommendations to launch new screening programs should be based on evidence from high-quality RCTs that screening results in sufficiently positive outcomes to justify the costs and potential harms of screening [1,4,5]. RCTs that test the effects of a screening program should at a minimum (1) randomize patients prior to the screening intervention and (2) provide similar treatment resources to patients detected with the condition or health problem in the screening and non-screening trial arms. Otherwise, the effects of screening and the effects of depression treatment, once depression is detected through screening or otherwise, cannot be separated [1,4,5]. The USPSTF has argued that there is evidence that screening and treatment improve depression outcomes [2,3]. Similar organizations, including the CTFPHC [7] and the UKNSC [8], however, have determined that there is not trial evidence to suggest benefit from depression screening, and both the CTFPHC and UKNSC recommend against this practice. In its recommendation, the CTFPHC [7] criticized the USPSTF for considering trials of depression care management programs as evidence on screening, since these trials used screening tools to establish trial eligibility prior to randomization, but did not test screening programs. Consistent with this, a recent study found that only 2 of 13 RCTs described by the USPSTF as screening trials separated screening from treatment [6]. One of those two trials reported that screening did not improve depression outcomes, and the other reported equivocal results, but there were concerns that what was reported did not represent what would likely occur in practice [6].

Beyond RCTs, attempts to implement screening in practice make it clear that skepticism is warranted. Investigators from the Netherlands attempted to screen patients and then provide collaborative depression care for high-risk primary care patients, including patients with a previous mental health problem, unexplained somatic complaints, or a high level of primary care service utilization. In that study, 1687 patients were sent a screening questionnaire with a letter from their general practitioner; 780 returned the questionnaire, and while 226 (29%) screened positive, only 17 patients (1% of those invited) initiated treatment for depression [9]. Notably, the number needed to treat for clinical improvement with antidepressants is 7 to 8 [10].

From 2006 to 2013, the UK Quality and Outcomes Framework financially incentivized routine depression screening of primary care patients with coronary heart disease or diabetes. It was estimated, however, that 976 patients had to be screened for each new diagnosis of depression and 687 for each new antidepressant prescription [11]. In 2013, depression screening was discontinued as a quality indicator.

4. Depression screening would harm some patients

There is a maxim that ‘All screening programmes do harm; some do good as well’ [12]. Approximately 13% of Americans took antidepressants in the last year [13], and others received psychological therapies. Depression screening would not lead to better care for those patients, but would only identify more individuals as possibly needing care. Some patients with false-positive screens will be correctly determined to not need treatment, but some number of patients will be treated without benefit. Indeed, all medical screening programs lead to the diagnosis and treatment of some patients who do not benefit, and this would also occur if depression screening were done. In the absence of evidence of benefit, the potential for overdiagnosis and overtreatment is concerning, particularly because the majority of patients who are treated for depression in the United States do not meet diagnostic criteria [14]. Potential harms include labeling of some problems that will resolve on their own as medical problems, as well as nocebo effects from telling patients who are not otherwise concerned that they have a diagnosis of depression [5]. Some number of patients who are subjected to screening, but do not benefit, will experience common side effects of antidepressants, including diarrhea, dizziness, dry mouth, fatigue, headache, nausea, sexual dysfunction, excessive sweating, tremors, and weight gain. Others will experience less common but more potentially serious adverse events, such as bleeding, effects on blood pressure and heart rate, and negative drug–drug interactions with other medications [9].

5. Depression screening would consume valuable health-care resources

The USPSTF does not consider cost and resource implications in its recommendations. While some have argued that screening questionnaires can be administered at little cost, a depression screening program would involve much more than passing out questionnaires. Such a program would need to include further assessment for patients who screen positive, consultations on management options, and treatment and follow-up services. One study reported that in primary care visits that include depression screening, more than 70% last at least 15 min and that 17% last more than 30 min compared to 42% and 6% when screening is not done [15]. Although it depends on the clinical setting and population, it is reasonable to expect that as many as 30% of primary care patients would screen positive and need follow-up assessments, even though the majority of these would represent false-positive screens [16].

It is well known that primary care providers are overburdened and cannot both address the immediate needs of their patients and provide all of the recommendations for prevention activities that have been made by the USPSTF. By 1996, based on a conservative estimate, a typical primary care physician in the US had to spend 7 to 8 h per day just to minimally comply with Grade A and B (should be provided) USPSTF recommendations [17]. Since 1996, the number of recommendations has increased. The USPSTF does not provide guidance on how to prioritize recommendations, but primary care providers in the US do not seem convinced that screening is a resource-wise activity. In 2012 to 2013, only 4% of primary care patients in the US were screened for depression, even though it was recommended by the USPSTF and covered per the Affordable Care Act [18].

6. Conclusion

Depression is an important condition that negatively affects quality of life. As part of standard care, clinicians should provide good mental health assessment. They should be alert to clinical cues that depression may be present, such as low mood, insomnia, anhedonia, or fatigue. They should be particularly aware with patients who may be at greater risk, including those with a family or personal history or those with a chronic medical condition, chronic pain, a history of traumatic life events, and drug or alcohol abuse, for example [1]. There are some conditions, like diabetes mellitus, that almost always require screening or other special laboratory testing to diagnose. Depression is not one of those conditions. Primary care providers are expected to have the necessary knowledge and expertise to diagnose and treat common health conditions like depression, and if they do not, they should obtain it. Indeed, a lack of knowledge is no excuse for using a screening tool with unacceptable test characteristics on all patients, and the best available evidence suggests that doing so would likely lead to more harm than good. Screening is not a substitute for good medical care.

The USPSTF was recently criticized by experts for the uncritical use of indirect evidence and for not adequately considering potential harms in recommending depression screening [19]. When high-quality trials are feasibly conducted, as is the case with depression screening, calls for screening should be based on direct evidence from RCTs of screening programs. Without such evidence, the USPSTF should reconsider its recommendations to screen for depression.

Declaration of interest

B.D. Thombs was supported by an Investigator Salary Award from the Arthritis Society. R.C. Ziegelstein was supported by the Miller Family Scholar Program of the Johns Hopkins Center for Innovative Medicine. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

This paper was not funded.