Sickness, chronic illness and depression are often intertwined. Certain physical conditions can trigger depression, such as hypo- or hyperthyroidism. Depression is also common among people with life-threatening illness: Cancer and depression coexist in up to 25 percent of cancer cases, according to the National Cancer Institute. While depression is a mental disorder, it can have very physical consequences.

Physical Causes of Depression

A personÕs risk of depression increases with certain physical conditions. Cases of sickness and depression are often seen in medical cases that include:

  • Fibromyalgia
  • Food allergies
  • Heavy metal toxicity
  • Hormonal disorders
  • Hypoglycemia
  • Nutritional deficiencies
  • Selenium toxicity
  • Sleep disturbances
  • Thyroid problems
  • Yeast infections.

Chronic Illness and Depression

Chronic illness changes a personÕs life. Quality of life is negatively affected. Symptoms of the illness may cause pain, reduce mobility or limit activities. In some cases of chronic illness, death is either a possibility or a certainty.

People react to serious chronic illness in different ways. Many initial coping strategies resemble symptoms of depression, including anger, sadness and social withdrawal. If emotional distress does not improve over time, depression may be a factor.

A combination of sickness and depression can have serious consequences. A depressed individual is less likely to engage fully in his treatment, and may choose not to comply with essential treatment.

Depression also appears to impair the immune system, leaving people at greater risk of serious illness and infection. According to an article by Siobhan MacHale in the Advances of Psychiatric Treatment, depressed individuals with serious disease have greater mortality rates than patients with the same disease who were not depressed.

Examples of chronic illnesses that increase a person’s risk of depression include:

  • AIDS
  • Brain injury
  • Cancer
  • Diabetes
  • Heart disease
  • Liver/kidney disease
  • Lung disease
  • Multiple sclerosis
  • ParkinsonÕs disease
  • Rheumatoid arthritis
  • Stroke.

Cancer and Depression

Cancer deserves a special mention in any discussion of sickness and depression. Popular beliefs about cancer suggest that all cancer is a death sentence Рa belief that, at best, is inaccurate. However incorrect this view is, people react to cancer with a dread that other diseases often don̥t elicit. Such beliefs increase the risk that cancer and depression will occur together.

Diagnosing depression in cancer patients can be difficult. While fatigue, weight loss, sleep disturbances and cognitive difficulties are symptoms of depression, such symptoms can occur due to cancer treatment or the disease itself. Symptoms that occur every day for two months, however, may indicate the presence of depression.

Illness and depression don’t need to go hand-in-hand. Successfully treating depression in patients with serious illness improves both quality of life and treatment outcomes.


American Cancer Society Staff. (2009). Depression. Retrieved May 8, 2010, from the American Cancer Society website:

Healthy Place Staff. (2010). Medical illness and depression. Retrieved May 8, 2010, from the Healthy Place website:

McHale, S. (2002). Managing depression in physical illness. Retrieved May 8, 2010, from the Advances in Psychiatric Treatment website:

National Cancer Institute Staff. (2010). Depression (PDQ). Retrieved May 8, 2010, from the National Cancer Institute website:

 Posted on : June 26, 2014