Comorbidities

Comorbidity is a term used to refer to a disorder that is not directly caused by another disorder but occurs at the same time. For instance, if you have both migraine attacks and asthma, either one is a comorbidity for the other. It’s useful for doctors to know about comorbidities, so that they can realize the likelihood of another diagnosis in someone with an established disease but additional or disparate symptoms.

There have been recent publications that show unexpected comorbidities. For instance, a National Headache Foundation press release says that people with migraine had likelihoods of co-existing conditions as follows:

Depression – 54%

Anxiety disorder – 34%

Chronic Fatigue Syndrome – 20%

Asthma – 17%

Fibromyalgia – 17%.

Migraine is a common condition and so are the others on this list; it’s just an indication of which disorders may co-exist, or be co-morbid.

Here’s another example. A publication in BMC Gastroenterology, an online medical journal, has reported on comorbidities with irritable bowel syndrome, or IBS. It finds that people with IBS have a 40% to 80% higher likelihood of migraine, fibromyalgia, and depression.

This sort of analysis doesn’t address the ‘chicken and egg’ problem, or possible cause-and-effect relationships. Thus we don’t know if depression ‘causes’ migraine, or (more likely) the other way around; or whether there’s a genetic or environmental factor that helps produce both conditions. But as more comorbidities are recognized it’s likely that the cause-and-effect question will be answered for each, one after the other, though it may take some years.