Background - Depression and Heart Disease
Depression and heart disease: How common is this?Heart disease and depression are both high prevalence disorders and are forecast to be the two leading contributors to burden of disease by the year 2020 (Murray & Lopez 1996).
Comorbidity refers to the occurrence of more than one disorder at the same time. "When depression appears in conjunction with other disorders it produces even more disability than when it occurs in isolation" (Sartorius et al 1996). Numerous studies have shown a disproportionately high prevalence of depression in patients with heart disease (Lett et al. 2004). As many as 45% of patients report feeling depressed after a heart attack (Schleifer et al. 1989), including about 20% with symptoms of major depression. This is substantially higher than depression rates in the general population. A community survey in South Australia found 17.4% with depressive symptoms, of which 6.8% of people reported symptoms of major depression (Hawthorne et al. 2003).
The link between depression and heart diseaseDepression can develop without apparent cause, although stressful circumstances including a serious or life-threatening illness can be a trigger. Depression has also been found to increase the risk of developing a cardiac condition. Hence depression is a concern - whether it occurs alone or after heart disease has developed.
Although depression severity is independent of cardiac disease severity (Schleifer et al. 1989), there are several behavioural and biological explanations for the association between depression and heart disease (Lett et al. 2004).
Depressed patients may neglect their health, not comply with recommended treatments or lifestyle modifications, and have several cardiac risk factors eg. smoking, alcohol consumption, physical inactivity.
Depression is associated with chemical changes in the body. These changes may also increase the risk of a cardiac event in patients with depression, probably through the release of stress hormones and changes in blood coagulation.
Depression is more than a feeling of sadness or unhappiness. Anyone experiencing a number of the following symptoms every day for at least two weeks and they are interfering with daily activities should be advised to see their General Practitioner. Symptoms of depression include:
- weight loss or gain, with increase or decrease in appetite;
- insomnia or hypersomnia (difficulty sleeping or excessive tiredness);
- feeling agitated or sluggish;
- fatigue or loss of energy;
- feelings of hopelessness, worthlessness or guilt;
- diminished ability to concentrate, indecisiveness;
- recurrent thoughts of death or suicide.
What are the consequences on health outcomes?The Australian Heart Foundation (Bunker et al. 2003) recently highlighted evidence that depression is an independent risk factor for poorer prognosis in patients with heart disease. This increased risk is of similar order to the conventional risk factors of smoking, high cholesterol and hypertension. Major depression increases the risk of poor prognosis by 3-5 times, but even mild depression can double the risk.
Depression has been found to predict quality of life (QoL) better than physiological measures of cardiac function (Ruo et al. 2003). Depression in cardiac patients is associated with increased length of hospital stay, more readmissions and more outpatient medical visits, for mild as well as major depression (Frasure-Smith et al. 2000).
Psychosocial interventions, exercise programs and antidepressant medications have all been found to provide some benefit in treating depression in heart disease patients (Lett et al 2004). Although several large studies ie. SADHART (Glassman et al. 2002) and ENRICHD (Berkman et al. 2003), have investigated the effect of treatments for major depression on cardiac outcomes, further clinical trials are needed. Treatment with the selective serotonin release inhibitor (SSRI) anti-depressant (Sertraline) was found to improve quality of life in the subgroup of SADHART patients with major depression who had a history of recurrent depression (Swenson et al. 2003).
Depression often becomes a chronic disorder. Even with treatment, many people do not recover completely from major depression (Andrews et al. 2000). Studies are still needed to determine the time-course of depression in patients with a physical illness. One study of cardiac patients found that depression resolved in only 23% of patients with major depression by 3-4 months after a heart attack, although 65% of those with mild depression recovered (Schleifer et al 1989). This indicates that it may be important to identify those patients in whom depression is likely to persist or reoccur.
Depression often undiagnosed and untreated in patients with physical illnessAlthough depression is known to adversely impact upon recovery from a physical illness, many doctors (and patients) accept that depression may be a natural reaction to a cardiac event (Guck et al. 2001), resulting in comorbid depression often being unrecognised, or untreated, or poorly treated ( Hickie 1999).
- Some symptoms are common to both depression and heart disease
- Physicians and patients may erroneously believe that depression is a normal reaction to heart disease or a cardiac event
- Patients may be reluctant to report symptoms of depression
- Physicians may be reluctant to ask about depression
- Physicians may be reluctant to prescribe antidepressant medications to patients with heart disease because of potential for interactions with their other medications.One researcher found that less than 25% of cardiac patients with major depression were diagnosed with depression, and only about 50% of those who were diagnosed then received treatment for depression (Musselman, Evans & Nemeroff 1998).
Psychological disorders which occur in the context of obvious life stressors are typically described as `adjustment disorders' which imply a maladaptive behavioural responses which is short-lived and associated with minor degrees of disability. "This approach substantially underestimates the impact of such presentations on primary care practitioners and the degree of risk and disability which may result". (Hickie, 1999).
Screening tests can assist identification of symptoms of depression (Nease, Malouin 2003), but providing doctors with screening test results alone has not been found to increase treatment of depression (Gilbody, House & Sheldon 2001 ). Screening for depression is likely to be of benefit when undertaken in association with procedures to promote evidence-based treatment of depression (Pignone et al. 2002, Hickie, Davenport & Ricci 2002). A multi-faceted approach to disseminating and implementing guidelines or evidence based management is recommended, and little benefit is gained from passive methods (Feder et al 1999).
Characteristics which may assist by identifying patients at risk of developing depression (Guck et al 2001) are:
- History of depression
- Family history of depression
- Lack of social support (especially if living alone)
- Loss of functioning or major life role
- Female gender
Anxiety, hostility and other emotional factors
- Anxiety disorders
- Panic disorders
- Chronic life events
- Work related stressors (job control, demands and strain)
- Type A behaviour patterns
Depression with other diseasesDepression is frequently comorbid with other chronic conditions including diabetes, stroke, Parkinson's disease, cancer, arthritis and chronic obstructive pulmonary disease. Comorbid depression can delay recovery and increase risk of poorer medical outcomes (Spollen, Gutman 2003).
- Heart Foundation www.heartfoundation.com.au
ReferencesAmerican Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders, 4th Edn. Washington, DC: American Psychiatric Press, 1994.
Andrews G et al. Why does the burden of disease persist? Relating the burden of anxiety and depression to the effectiveness of treatment. Bull World Health Org 2000; 78:446-454.
Berkman LF et al. Effects of treating depression and low perceived social support on clinical events after myocardial infarction: the Enhancing Recovery in Coronary Heart Disease Patients (ENRICHD) Randomized Trial. JAMA 2003;289(23):3106-16.
Bunker SJ et al. "Stress" and coronary heart disease: psychosocial risk factors. Med J Aust 2003;178(6):272-6.
Frasure-Smith N, Lesperance F, Talajic M. Depression following myocardial infarction. Impact on 6-month survival. JAMA 1993;270(15):1819-25.
Gilbody SM, House AO, Sheldon TA. Routinely administered questionnaires for depression and anxiety: systematic review. BMJ 2001; 322:406-4096.
Glassman AH et al. Sertraline treatment of major depression in patients with acute MI or unstable angina. JAMA 2002;288(6):701-9.
Guck TP et al. Assessment and treatment of depression following myocardial infarction. Am Fam Physician 2001;64:641-648.
Hawthorne G et al. The excess cost of depression in South Australia: a population-based study. Aust NZ J Psychiatry 2003; 37:362-373.
Hickie IB. Primary care psychiatry is not specialist psychiatry in general practice. Med J Aust 1999; 170:171-173.
Hickie IB, Davenport TA, Ricci CS. Screening for depression in general practice and related medical settings. Med J Aust. 2002; S111-S116.
Lesperence F et al.. Depression and 1-year prognosis in unstable angina. Arch Intern Med 2000;160:1354-1360.
Lett HS et al. Depression as a risk factor for coronary artery disease: evidence, mechanisms and treatment. Psychosom Med 2004;66:305-315.
Nease DE, Malouin JM. Depression screening- a practical strategy. The Journal of Family Practice 2003 52(2) http://www.jfponline.com/contents/2003/jfp_0203_0018.asp
Penninx BW et al. Depression and cardiac mortality: results from a community-based longitudinal study. Arch Gen Psychiatry 2001; 58:221-227.
Pignone MP et al. Screening for depression in adults: a summary of the evidence for the U.S. Preventative Services Task Force. Ann Intern Med 2002; 136:765-776.
Sartorius N et al. Depression comorbid with anxiety. Resullts from the WHO study on psychological disorders in primary care. Br J Psychiatry. 1996; 168:Suppl 30:S38-S43.
Schleifer SJ et al. The nature and course of depression following myocardial infarction. Arch Intern Med 1989; 140:1785-1789.
Spollen JJ, Gutman D. The interaction of depression and medical illness. Depression and Comorbid Cardiovascular Disease. 2003; http://www.medscape.com/viewarticle/457165
Swenson JR et al. Influence of depression and effect of treatment with Sertraline on Quality of Life after hospitalisation for Acute Coronary Syndrome. The American Journal of Cardiology 2003; 92:1271-1276.
Phone: (08) 8226 6024
Fax: (08) 8226 6700
Privacy | Disclaimer
| Copyright © Department of Health 2004