When researching psychology, one of the terms that tend to pop up a lot is comorbidity. Whether discussing the relationship between two or more mental disorders, physical disorders, or a mix of the two, the term shows up more and more the farther you delve into studying psychology. But what does this term mean and why does it appear so much in both mental and physical health studies?
First introduced in 1970 by epidemiologist and doctor A.R. Feinstein, it refers to the co-existence of multiple disorders within one person. While his specific example of the term was how patients with rheumatic fever also suffer from other diseases, it has come to be used across the medical field to refer to when multiple disorders exist within the same person. While the idea that one patient can be suffering from multiple conditions at the same time certainly wasn’t a new one in 1970, before the inception of modern medicine, doctors didn’t necessarily have a wide range of diagnoses to choose from. With the change to focusing on specification due to the variety of treatments available, doctors needed to learn how to treat patients who suffered from multiple disorders and learn which disorders required primary treatment. Within the medical field, there are three different definitions for “comorbid”: medical conditions existing together but independently within a patient, a medical condition caused by another condition, or two or more medical conditions existing simultaneously in a patient regardless of the relationship between the conditions. In mental health, which we’ll be focusing on for this article, comorbidity is used to refer to disorders that often coexist together, for example, depression and anxiety. It can also be used to refer to a patient who has both physical and mental diagnoses, such as someone who has depression and migraines.
It’s very common for people with mental disorders to be suffering from more than one. Studies have shown that over half of the population struggling with disorders like depression also suffers from another mental condition. Most commonly this is anxiety, but other disorders such as personality disorders, substance abuse disorders, and autism spectrum disorders can exist comorbidly with depression. Patients can also develop comorbid disorders due to a delay in treatment or misdiagnosis, further compounding the issue. A person with chronic pain may develop depression or substance abuse disorders trying to combat the pain if they are left untreated or constantly told that there is nothing wrong with them. While this not only leads to greater distress for the patient, it can lead to stumbling blocks and issues when it comes to a person’s treatment as well. This is why a doctor needs to be aware of, and take seriously, all the disorders that a patient has, whether mental or physical. If a medical doctor doesn’t take a patient’s mental health into account then at best the mental disorders can go untreated and at worst they can get worse or compound the physical disorders. If a therapist doesn’t take into consideration a patient’s physical health, then they’re dismissing what may be causing some of the mental health issues. Mental and physical health issues don’t exist in a vacuum shouldn’t be treated as if they don’t affect each other.
One of the stumbling blocks that comorbidity creates is especially apparent when it comes to the treatment of the different disorders. While any disorder that someone is suffering from needs to be treated, an overlap of medication, side effects, and other treatments can cause issues when it comes to treating multiple kinds of illnesses. Certain medications can have potentially lethal side effects when taken together and each person’s body will react to different medications differently. While some patients with depression may react fine to Zoloft, others will have a whole host of side effects and have to switch to a different medication. Doctors and psychologists need to be aware of what medication a patient is taking for their comorbid disorders to ensure none of the medications will react negatively with each other.
While comorbidity can seem like a simple concept, two disorders appearing in one patient, it’s an extremely complex topic. The relationship between these disorders, whether mental or physical, can greatly affect a patient’s life and doctors need to be aware of them even if they don’t commonly treat that kind of disorder. Understanding comorbidity rates, or how common it is for one disorder to appear with another, can also help a patient understand their own symptoms, which symptoms can be a sign of which disorder, and which symptoms appear in both disorders separately. By understanding the relationship between disorders, patients and doctors can better understand symptoms and help find the best treatment for a patient to live their best life.
