There’s a strong relationship between physical and mental health conditions. People with chronic physical illnesses are twice as likely to suffer from anxiety or depression as their physically healthy counterparts — and for specific health conditions, the rate is even higher.1

Physically ill individuals may also develop post-traumatic stress disorder (PTSD). A study of cancer patients found that one in five developed PTSD after their diagnosis.2 The rate is similar (between 15 and 35 percent) for people with chronic pain.3

Chronic Physical Illness Can Influence Mental Health Directly or Indirectly

Physical illnesses can predispose people to mental illnesses in part because many physical conditions are associated with abnormal levels of hormones and neurotransmitters that can affect mental health. Parkinson’s disease, for example, involves abnormalities in the dopamine system. Chronic pain is associated with imbalances of GABA, serotonin, dopamine, and norepinephrine.

Any health condition that causes widespread inflammation may raise the risk of depression because depression has been associated with inflammation in the brain.

Chronic illness may also affect mental health through the mechanism of increased stress. There are many possible stressors and many common emotions associated with physical disease. The initial diagnosis may bring grief and shock. It’s common to feel angry about the change of lifestyle and feel misunderstood by friends and family members who don’t have the same limitations. These feelings are normal and not in themselves evidence of mental illness, but the circumstances and associated emotions can add to the body’s level of psychological stress, which can be damaging when levels rise too high.

Studies at the University of California, Berkeley, found that chronic stress causes the body to generate fewer neurons than normal and more myelin-producing cells. This changes the ratio of gray matter to white matter in the brain. The hippocampus — the part of the brain that regulates emotions and is associated with emotional disorders — was shown to be affected by this process. Researchers believe the changes may explain why people under chronic stress are more likely to develop mood disorders, anxiety, and other mental health conditions.4

Medications and Mental Health

Sometimes it’s not the disease itself that increases the risk of developing a mental illness, but the medications used to treat it. A surprising number of medications are known to contribute to depression, including the following:

  • Beta-blockers – People suffering from high blood pressure, angina, migraines, tremors, irregular heartbeat and some types of glaucoma may be prescribed these medications. Many drugs that have names ending in “-olol” are beta-blockers, including metoprolol, propranolol and atenolol.
  • Statins – Statins are generally prescribed to lower cholesterol. The drugs may contribute to depression because cholesterol in the brain helps release neurotransmitters.
  • Interferon alfa – This medication may be prescribed to treat hepatitis or certain cancers, like melanoma.
  • Opioids – Opioid pain relievers like morphine, oxycodone and hydrocodone may initially cause euphoria, but can contribute to depression over time due to their effects on dopamine and GABA.
  • Anticonvulsants – Drugs in this class, including Neurontin, Lyrica and Lamictal, are used to treat seizures, fibromyalgia, neuropathy and a wide variety of other health conditions.
  • Corticosteroids – These drugs, which include cortisone and prednisone, are anti-inflammatory and used to treat conditions such as lupus, gout and rheumatoid arthritis. They may cause depression by their effect on serotonin levels.
  • Stimulants – Stimulant drugs like Ritalin may be prescribed to treat attention deficit hyperactivity disorder (ADHD), fatigue and daytime sleepiness. They alter dopamine levels, which may contribute to depression.

Anxiety is also a possible side effect of many medications. Some drugs, such as steroids, stimulants and blood pressure medications, may cause anxiety in addition to, or instead of, depression. Other drugs that may cause or contribute to anxiety include asthma and thyroid medications. Low blood sugar can contribute to both depression and anxiety, so when diabetic medication lowers glucose levels beyond the desired range, mental health symptoms can result.

The Importance of Treating Mind and Body

Mental health conditions can be effectively treated whether or not a chronic disease is also in the picture. But, when possible, it’s best for health practitioners to work together and coordinate care. Treatment may involve changing or adding medications as well as using Cognitive Behavioral Therapy (CBT) or other talk therapies. Stress reduction and management techniques may also be very helpful.

Not every physical health condition can be quickly or easily resolved, but it’s always appropriate to address the mental health issues that may arise. There’s often a cyclical relationship, where suffering from depression, for example, makes it harder to maintain the energy and motivation needed to work on improving the physical illness. Addressing the mental health aspects of a condition can greatly improve someone’s quality of life.

By Martha McLaughlin


1The Relationship Between Mental Health, Mental Illness and Chronic Physical Conditions.” Canadian Mental Health Association, Accessed January 1, 2018.

2 Hoffman, Matt. “High Incidence of PTSD Among Cancer Patients.” MD Magazine, November 20, 2017.

3Chronic Pain and PTSD: A Guide for Patients.” US Department of Veterans Affairs, August 13, 2015.

4 Sanders, Robert. “New evidence that chronic stress predisposes brain to mental illness.” Berkeley News, February 11, 2014.