Screening pulmonary hypertension patients for depression

Pulmonary arterial hypertension (PAH) is a rare and debilitating disease characterised by progressive increases in pulmonary arterial pressure and pulmonary vascular resistance, leading to right ventricular failure and death (1-4). As there is no cure, the primary goal of disease management is to alleviate symptoms and prolong survival. Although treatment of patients with PAH with agents such as prostanoids, endothelin receptor antagonists and phosphodiesterase inhibitors have been shown to improve exercise capacity (5, 6), many patients still experience diminished quality of life, severe limitations in mobility requiring lifestyle modifications, and a potential for social isolation. The physical burden imposed by PAH may result in loss of work, adding to the worry about paying for expensive therapies. Despite improvements in the treatment of PAH, patients still suffer from the uncertainty of this progressive disease. Thus, patients with PAH can accumulate a number of life stressors which have been associated with the development of depression (7). As a result of diminished quality of life, decreased mobility, social isolation, financial burdens, unemployment and an uncertain prognosis, patients with PAH may be more vulnerable to developing depression. This perspective provides rationale for the importance of routine screening of PAH patients for depressive symptoms. Patients with pulmonary arterial hypertension can accumulate a number of life stressors, including physical, emotional and social burdens, which have been associated with the development of depression. According to the World Health Organization (WHO), depression is the leading cause of disability as measured by Years Living with a Disability, and organisations such as the Institute of Medicine emphasise that depression screening and treatment should be a priority for US medicine in the 21st century (8). This is particularly true for PAH patients for the reasons noted above. Importantly, data from the REVEAL registry(9), a multicenter observation cohort study of WHO Group I PAH, shows that of the most frequent comorbid conditions experienced by PAH patients (including hypertension, thyroid disease and obesity), clinical depression is the single most clinically significant condition that predicts medical disability in patients with PAH (10). A recent study performed at two large PAH referral centres has shown that depression is common in PAH patients, with 55% of PAH patients demonstrating depressive symptoms (11). This study utilised a simple and well-validated instrument, the Patient Health Questionnaire-8 (PHQ-8) (12), to determine the prevalence and severity of depressive symptoms in patients with PAH. The PHQ-8 is a useful measure for establishing the presence of depressive symptoms, and it has the capability of identifying an “at-risk” group or one that may also need treatment even though not meeting strict criteria for major depressive disorder. Data from the REVEAL Registry demonstrated that 25% of patients report a history of depression (9). This registry relied upon self-reporting a history of depression, as opposed to utilisation of a standardised instrument, like the PHQ-8, with good sensitivity and specificity for the detection of depressive symptoms. The difference between this self-reported frequency of a history of depression, and the prevalence of depressive symptoms detected using an instrument like the PHQ-8, illustrates the importance of the routine screening of PAH patients for depressive symptoms. The sensitivity for detecting the presence of depressive symptoms may be considerably higher using a screening instrument. In spite of the frequency of depression as a comorbidity in patients with PAH, formal screening and treatment of depressive disorders is not currently a common practice in most pulmonary hypertension referral centres. A majority of patients are seen in their respective pulmonary hypertension clinics every 3–6 months, making the PAH provider well positioned to recognise and address concurrent psychiatric illness. Continuity of care is especially important in managing patients with a long term, life-threatening illness such as pulmonary hypertension. Unfortunately, however, inadequate assessment for depression and other co-morbid psychiatric disorders is the rule rather than the exception. In a busy pulmonary hypertension practice, clinic time with each patient is limited, patients need to be assessed rapidly, tests need to be ordered, and very little time remains to be spent addressing the patient’s psychosocial needs. In addition, PAH providers may lack the training to adequately address their patients’ psychiatric disorders. Undiagnosed comorbid depression makes it difficult for the provider to properly evaluate the patient. We depend on our patients to comply with their medical regimen, but if they are depressed, their medication adherence may be erratic. The presence of depression might also affect their reporting of symptoms, and make it more difficult for the provider to determine the correct plan of care. It is also possible that depression might affect functional assessment of the patient. The 6-min walk test has been one of the non-invasive standards for evaluating pulmonary hypertension, but one might ask whether the patient is walking slower because of worsening disease, or because they are depressed and unmotivated, or perhaps because their depression reduces their compliance with taking medications? A false impression of the patient’s functional capacity might influence the prescription of expensive therapies with potential side effects. Patient reported symptoms, and the formal assessment of their functional class, might also be influenced by the presence of depression. The patient’s complaints of increasing fatigue and worsening symptoms may in fact be depression rather than disease progression. Routine screening of pulmonary hypertension patients for depression is likely to improve detection of depression in this patient population. Without a plan for screening and referral, depression may be under-diagnosed and undertreated by PAH providers. Our recent study (11) found that 69% of patients with mild-to-moderate depressive symptoms were not on antidepressant therapy, and 50% of patients with severe depressive symptoms were not taking an antidepressant. Patients who are emotionally distressed may choose not to seek help for fear of stigmatisation, or they may wish to attempt to solve the problem on their own. If we don’t ask, or screen, we may never know. Depression may be insidious in onset, and patients as well as providers may struggle to discriminate between changes in mood and changes in their state of health. A patient who is followed for years in their PH clinic may undergo transition through different stages of coping with their disease, and ongoing assessment is necessary to detect these potentially important changes. Without a plan for screening and referral, depression may be under-diagnosed and undertreated by PAH providers. Undiagnosed comorbid depression makes it difficult for the provider to properly evaluate the PAH patient. Several simple screening tools exist for the detection of depressive symptoms, including the 2-, 8- and 9-item Patient Health Questionnaires (PHQ-2, PHQ-8 and PHQ-9) (12-14). These screening tools focus on the frequency that patients suffer from specific depressive symptoms. The PHQ-8 and -9 have been found to be both sensitive and specific for diagnosing major depressive disorder. These tools are time-efficient and could be integrated into standard inpatient and outpatient evaluations. Patients can complete the questionnaire while waiting in the waiting room, and results of the test can be reviewed by the provider. The practice of universal depression screening of PH patients should be accompanied by a plan for referral for further evaluation and treatment if needed.This might involve communication with the patient’s primary care provider, or perhaps referral to a specialist, such as a psychiatrist. Such a plan ensures that affected patients would undergo a more thorough evaluation for depression, and would have resources available for treatment if needed, including pharmacological and/or psychotherapeutical options. The choice of therapy may depend on available resources and patient preferences. An important component of any evaluation includes assessment of risk for suicide, which is a major complication of depression. In addition, depressed individuals frequently suffer from other psychiatric illnesses, such as anxiety disorders and substance dependence, which may be contributing to or exacerbating the depression. In light of the impact of depression on compliance, functional status and accurate assessment of the patient's symptoms, it is of paramount importance that depression be promptly detected and addressed. In conclusion, routine depression screening of all pulmonary hypertension patients is recommended, and should be accompanied by a plan for appropriate referral and management of affected patients. In light of the potential impact on compliance, functional status and accurate assessment of the patient’s symptoms, it is of paramount importance that depression be promptly detected and addressed.