There is considerable controversy about whether screening for depression should be part of standard care for patients with cardiovascular disease (CVD). A 2008 American Heart Association (AHA) Science Advisory recommended routine screening for depression in all patients with coronary heart disease (1), but a subsequent systematic review concluded there is no evidence that screening is of benefit (2). Others have suggested that screening for depression may benefit patients, but only if performed in the context of a collaborative care treatment model, including frequent follow-up by a case manager and streamlined access to a mental health provider (3- 4). Now, Ziegelstein et al. (5) say “Never mind,” and call for a reassessment of the AHA Science Advisory.

How do we make sense of all of this? Should patients with CVD be screened for depression? Will screening improve cardiovascular outcomes?

The 2008 AHA Science Advisory concluded that “Depression is commonly present in patients with coronary heart disease and is independently associated with increased cardiovascular morbidity and mortality. Therefore, screening tests for depressive symptoms should be applied to identify patients who may require further assessment and treatment” (1). Given the overwhelming evidence that depression is associated with adverse outcomes in patients with CVD, and the availability of easy-to-administer and reasonably accurate screening instruments (6), it is understandable to think that screening for depression would improve outcomes. Indeed, our primary care colleagues came to this same conclusion 15 years ago when depression had been clearly linked with poor medical outcomes (7), and it was thought that screening and informing health care providers about depression would improve these outcomes.

Unfortunately, subsequent randomized controlled trials addressing this very question found little if any benefit from screening for depression (8- 11). Although screening resulted in enhanced recognition and treatment, it did not improve depression because the majority of patients did not receive adequate dosage or duration of antidepressant therapy. Nearly one-half of patients discontinued treatment during the first month, and few received the recommended levels of follow-up care (12). Alas, it was concluded that “there is substantial evidence that routinely administered screening questionnaires for depression have minimal impact on the detection, management or outcome of depression” (13).

The question then became: what else is needed for screening to be of benefit? Numerous randomized trials were conducted to determine whether screening for depression, in combination with a collaborative care intervention, would improve outcomes (14- 21). These and other trials eventually concluded that screening can improve depression, but only when combined with a collaborative care intervention (3- 4,22). There were also potential harms of screening, including perceived stigma from false-positive results and diversion of health care resources from other needs. However, at least in primary care settings, these potential harms seemed to be outweighed by the benefits of screening plus collaborative care (23).

What is collaborative care? Katon and Unutzer (23) have identified 2 essential elements: 1) a depression care manager (an allied health professional, preferably with a mental health background) to educate patients, provide close follow-up, and monitor treatment adherence; and 2) a psychiatrist to provide case load supervision for depression care managers and clinical advice to primary care providers. Collaborative care interventions typically take 3 to 6 months, and many aspects of treatment can be accomplished over the telephone (4,24- 26). Although collaborative care programs can be associated with increased cost in the short term (27), they are cost effective and probably cost saving in the longer term (28- 30).

In theory, patients with CVD should be at least as likely as primary care patients to benefit from depression screening in the context of a collaborative care treatment program. However, only a few studies have specifically evaluated this in the cardiovascular care setting. Freedland et al. (31) screened patients for depression after coronary artery bypass surgery and randomly assigned those with depression to cognitive behavioral therapy, supportive stress management, or usual care. Participants who received cognitive behavioral therapy or supportive care were more likely to achieve remission of depression than those who received usual care. In the Bypassing the Blues Trial (32), patients were screened for depression after coronary artery bypass grafting, and those who screened positive were randomly assigned to a collaborative care treatment intervention versus usual care. This study has recently been completed, and preliminary results are promising (33). Another multicenter randomized trial is currently evaluating the effect of a heart failure management program that includes screening plus collaborative care for depression on cardiovascular health status (J. Rumsfeld, M. Sullivan, personal communication, April 2009).

Where does this leave current cardiovascular practice with regard to depression screening? To date, there is no evidence that screening plus collaborative care improves cardiovascular outcomes (2). Importantly, absence of evidence does not equal evidence of absence, and there is also no evidence that screening plus collaborative care has any negative effects on cardiovascular outcomes. However, until we can demonstrate that screening plus collaborative care improves cardiovascular outcomes, the responsibility for screening will continue to remain with the primary care provider.

Does this mean that cardiologists can ignore depression? Absolutely not. Depression is present in at least 1 in 5 patients with CVD and is associated with both poor quality of life and adverse cardiovascular outcomes (34- 36). Details about case finding and treatment for depression in patients with CVD have been described elsewhere (6). This simply means that routine screening of patients who are not otherwise suspected to have depression has no proven benefit outside of a collaborative care treatment program. When depression is recognized, the most evidence-based approach is for the cardiologist to make sure that the patient is evaluated by a primary care provider who can offer collaborative care treatment.

Depression meets most criteria for screening (common disease with significant morbidity, low cost and risk of screening, effective therapy available), but whether early detection and treatment improves cardiovascular outcomes is unknown. What we do know is that depression deserves treatment regardless of its cardiovascular effects, reasonable screening tools are available, and screening plus collaborative care is cost effective in primary care settings. Until we are able to demonstrate that screening for depression improves cardiovascular outcomes, patients with CVD should be screened for depression by primary care providers in the context of a collaborative care treatment program. The optimal frequency of depression screening will require further study.