The brain and body are intimately connected in health and illness.
Three Aspects of Health and Healing: The Biopsychosocial Model in Medicine
KEY POINTS
Common illnesses have psychological and social components that combine with biology to cause disease.
Biopsychosocial Model: Definition & Example
The biopsychosocial model approaches illness in a multifactorial way.
Biopsychosocial Model
George Engel was the pioneer of the biopsychosocial model of disease.
Engel’s model included the biological, psychological, and social dimensions of an individuals's life.
The belief that the mind and body are separate entities makes no sense, right? If I cut off your head, could you continue to live? Of course not! But, for a few brilliant philosophers and early physicians, the mind and body were thought of as distinct entities for centuries. However, we now know many illnesses are significantly impacted not only by biological factors but by psychological and social factors as well.
For example, untreated depression is an independent risk factor for cardiovascular disease. Anxiety can cause gastrointestinal illness. Stressful home or work environments can initiate or exacerbate the symptoms of autoimmune disorders. To successfully treat these disorders, a more holistic approach to illness management was conceptualized by some early pioneers in medicine. In the decades that followed, this would evolve into the biopsychosocial model.
In the 19th and 20th centuries, as medicine advanced, greater emphasis was placed on cellular mechanisms of disease. When Pasteur and Koch made their discoveries about the role of bacteria in disease, they laid the groundwork for the principle that for every disease, there is a single specific cause. As a result, mental or emotional factors took a less prominent role.
George Engel, the most prominent pioneer of the biopsychosocial model of disease, was born into a prominent medical family in 1913. He was greatly influenced by his uncle Manny, a famous physician who treated an elite clientele. George was also influenced by his mother but in a different way. Mrs. Engel was described as “dramatic” and suffered from multiple physical complaints that were out of proportion to any physical findings. She was diagnosed as a “hysteric” because no biological basis could be found for her many physical symptoms. In modern terms, she most likely had an illness that would be classified as psychosomatic, a term later made famous by her son. As an adult, George reflected, “She was an influence on my life with which I struggled—that it be my destiny to solve the problems Uncle Manny could not.”
During his extensive career, George’s focus remained on trying to understand how psychological phenomena could influence physiology. The principles of Engel’s model included the biological, psychological, and social dimensions of an individual’s life and the perception that individuals suffer as a whole, not as isolated organs. Physicians, therefore, should use a holistic approach regarding illness, including the patient’s emotional state as well as their environment.
How Is the Biopsychosocial Model of Illness Used Today?
The biopsychosocial (BPS) model of wellness and medicine examines how biological, psychological, and social elements impact health and disease. The BPS model stresses the interconnectedness of these factors. The causes of common illnesses such as heart disease and cancer have psychological and social components that combine with biology to cause illness.
For example, it is estimated that 30 percent of cancers are associated with tobacco use, and diet accounts for a proportion of digestive tract cancers. So, the biological factor may be a family predisposition to cancer, but if you smoke, that risk adds to your genetic loading. Similarly, if your family has a risk for gastrointestinal cancers and you eat a diet high in processed foods, red meat, and sugar, your risk increases overall.
On the other hand, understanding the various psychological and social risk factors for disease can help mitigate your genetic inheritance. For example, heart disease risks are increased by factors such as hypertension, smoking, high cholesterol, and type A personality traits. Learning to modify these risks can help offset the generic risk.
As an example, the biopsychosocial model was used to develop new treatment approaches for patients living with chronic pain, which affects approximately 50 million Americans.
Traditionally, pain research focused on sensory modalities, and neurological transmissions were identified only on a biological level. In other words, the experience of pain was conveyed directly from your skin to your brain without consideration of psychological or social factors. This was called the reductionist or biomedical view of pain.
Your nervous system is composed of two major parts or subdivisions, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS includes the brain and spinal cord. The brain is the body’s control center. The PNS is a vast network of nerves that are linked to the brain and the spinal cord. The gate control theory of pain was formulated in 1965 by a neurobiologist and a psychologist who proposed that spinal nerves act as gates that either allow pain to reach the brain, or close these gates and prevent pain messages from getting through.
This theory helped researchers understand how individuals experience different types of pain and develop strategies for treatment. So, what influences your perception of pain?
Emotions: Negative emotions like anxiety, depression, and chronic stress can increase pain. Once you’re in the cycle of depression and pain, it can be difficult to know whether your depression is making your pain worse, or whether your pain is worsening your depression
Brain disorders: Your brain is the processing center for pain, so if part of the brain isn’t working correctly, you might not process pain in a healthy way. People with schizophrenia, for example, often don’t perceive pain in the same way as those without this disorder.
Stronger signals: An old wife’s tale suggests if you hurt yourself, you should rub the affected spot. This is a great example of “closing the gates” of pain. When your brain perceives a secondary stronger signal coming in, it doesn’t pay as much attention to the first painful signal. My dentist demonstrated this to me one day when I needed a novocaine shot to have her work on my teeth. She was able to give me the shot without causing any pain because she put pressure on the inside of my cheek for a few minutes before inserting the needle loaded with anesthetic.
Drug use: Prescription medications as well as illegal drug use affect the way your body processes and perceives painful stimuli. Opioids, which are often prescribed for pain, have a strong “gate-closing” effect—usually. However, overusing opioids can cause a rebound effect and lead to increased sensitivity to pain over time.
Central sensitization: People with chronic pain often experience heightened pain responses to nearly everything. If you live with chronic pain daily, your nervous system develops an abnormal response to everyday stimuli. For example, clothing may hurt, and walking may be too painful to bear. In other words, things that seem innocuous and theoretically shouldn’t be perceived as painful, are the reality for those with conditions like rheumatoid arthritis or fibromyalgia. In these disorders, the body’s gates are left wide open and often require medical assistance to shut again.
There are other proven differences in how individuals perceive and respond to pain. Devising a “one size fits all” approach simply would not, and does not, work effectively.
As the biopsychosocial model evolved and spread through the scientific and medical communities, it became increasingly apparent that managing chronic pain through solely biological pathways was a dead end. This new approach offered valuable additional avenues for pain management that diversified the number of treatment providers capable of managing chronic pain and led to breakthrough clinical approaches with better outcomes.
Understanding these factors is critical to providing a successful treatment plan for those with chronic pain. For example, nutritional education, assessment, and treatment for sleep disturbance, and learning to moderate alcohol use can all improve the experience of pain for