Diseases such as vascular disease, diabetes, and chronic obstructive pulmonary disease (COPD) account for most of the deaths in the general population.¹ However, patients with depression often develop these medical conditions at an earlier age due to poor health behavior and the physiological effects of psychiatric disorders.²

It is recognized that patients with major depression and bipolar disorder die prematurely from secondary factors, such as having higher body mass index (BMI) and greater burden of endocrine/metabolic and respiratory disease, resulting from their mental condition.³ There is evidence that patients with depression die 5 to 10 years earlier than those without these mental disorders, and patients with bipolar disorder die 10 to 20 years earlier.²

Epidemiology of Depression and Chronic Diseases

Patients with chronic illnesses were found to have a 2- to 3-times higher rate of major depression compared to patients without these conditions of the same age and gender.⁴ Major depressive disorder has a prevalence of about 6.6% in the general population, with a lifetime prevalence of about 11%.⁴ Patients with depression have a 60% increased chance of developing type II diabetes.⁴

A systematic review of eight studies looked at the risk of depression for the onset of myocardial infarction. Clinically diagnosed major depressive disorder has been identified as a significant risk factor for the development of cardiovascular disease.⁵ Recent data suggest that about half of patients who develop depression after myocardial infarction have recurrent depressive episodes, and half experienced their first depressive episode after myocardial infarction.⁶

Medical Costs

Some studies have shown that patients with major depression tend to be high utilizers of general medical services.⁷ Two studies that evaluated the cost-effectiveness of depression treatment interventions in patients with major depression and diabetes found that interventions were associated with depression treatment and depression outcomes; it was shown that depression treatment was associated with both improved depression symptoms as well as decreased medical costs.⁷

Different environmental factors, on the other hand, may initiate common pathways that, in the end, promote diabetes and depression. A low socioeconomic status is one important factor that not only increases the risk of diabetes but also appears to be a cause of depression.⁸

A recent study examined patient follow-up for 5 years in patients with depression and diabetes. When compared with usual care, the collaborative care intervention, which included diabetes treatment, was associated with decreased direct medical costs.⁹ This means that effective depression treatment is associated with decreased health care costs associated with both depression and other comorbidities.

Role of Depression on Other Medical Comorbidities

Patients with chronic illness have a 2- to 3-times higher rate of depression compared to patients without chronic conditions.⁴ A recent review of 31 studies found that depression in patients with chronic medical illnesses such as diabetes, congestive heart failure, CHD, osteoarthritis, rheumatoid arthritis, asthma, or COPD was associated with a significantly higher number of medical symptoms than in those without depression.¹⁰ It was also found that depression was strongly associated with the number of symptoms compared to respective objectives measures.¹⁰ The evidence indicates that managing depression leads to improved symptoms associated with other chronic medical conditions.

In conclusion, depression is a risk factor for the development of chronic diseases such as diabetes and coronary heart disease, and it negatively affects severity and management of the chronic disease conditions. Depression is associated with increased medical symptoms, medical costs, and other aspects that negatively affect patients with chronic diseases. Depression care has been shown to be an effective and necessary way to care for patients with depression and other comorbidities. A multidisciplinary approach, including both metabolic conditions, such as diabetes, and mental conditions, such as depression, would help improve both disease outcomes, reduce disability adjusted life years, and would even reduce mortality.⁸

Resources:

1. The top 10 causes of death. World Health Organization. December 9, 2020. Accessed September 22, 2022. https://www.who.int/news-room/fact-sheets/detail/the-top-10-causes-of-death
2. Katon WJ. Epidemiology and treatment of depression in patients with chronic medical illness. Dialogues Clin Neurosci. 2011;13(1):7-23. doi:10.31887/DCNS.2011.13.1/wkaton
3. Gildengers AG, Whyte EM, Drayer RA, et al. Medical burden in late-life bipolar and major depressive disorders. Am J Geriatr Psychiatry. 2008;16(3):194-200. doi:10.1097/JGP.0b013e318157c5b1
4. Almeida SS, Zizzi FB, Cattaneo A, et al. Management and treatment of patients with major depressive disorder and chronic diseases: a multidisciplinary approach. Front Psychol. 2020;11:542444. doi:10.3389/fpsyg.2020.542444
5. Van der Kooy K, van Hout H, Marwijk H, Marten H, Stehouwer C, Beekman A. Depression and the risk for cardiovascular diseases: systematic review and meta analysis. Int J Geriatr Psychiatry. 2007;22(7):613-626. doi:10.1002/gps.1723
6. Spijkerman T, de Jonge P, van den Brink RHS, et al. Depression following myocardial infarction: first-ever versus ongoing and recurrent episodes. Gen Hosp Psychiatry. 2005;27(6):411-417. doi:10.1016/j.genhosppsych.2005.05.007
7. Katon W, Unützer J, Fan MY, et al. Cost-effectiveness and net benefit of enhanced treatment of depression for older adults with diabetes and depression. Diabetes Care. 2006;29(2):265-270. doi:10.2337/diacare.29.02.06.dc05-1572
8. Bădescu SV, Tătaru C, Kobylinska L, et al. The association between diabetes mellitus and depression. J Med Life. 2016;9(2):120-125.
9. Katon WJ, Russo JE, Von Korff M, Lin EHB, Ludman E, Ciechanowski PS. Long-term effects on medical costs of improving depression outcomes in patients with depression and diabetes. Diabetes Care. 2008;31(6):1155-1159. doi:10.2337/dc08-0032
10. Katon W, Lin EHB, Kroenke K. The association of depression and anxiety with medical symptom burden in patients with chronic medical illness. Gen Hosp Psychiatry. 2007;29(2):147-155. doi:10.1016/j.genhosppsych.2006.11.005