We know that migraine and depression are comorbid – they often go together. But why? Does one cause the other? Do they cause each other? Or is there a shared factor causing both?
Migraine and Depression – a common combination
Researchers in the Department of Neurology at the Leiden University Medical Centre in the Netherlands set out to see if there was a shared genetic factor. They found 360 migraine patients, carefully diagnosed. There were 209 that had migraine without aura, and 151 that had migraine with aura.
Then they measured heritability between migraine and depression in these patients.
Heritability is a complex measurement that tells us if genetic factors contribute to something. Without going into more detail, the researchers found that there was a connection between depression and both types of migraine.
But they still had to make some adjustments – some migraine patients are on antidepressants, for example.
But even after adjustments, it was obvious that genetic factors do contribute, at least in part, to the connection between depression and migraine. The connection is even stronger in migraine with aura.
This is further confirmation of the involvement of genetics in both migraine and depression, and the reality of a medical connection between the two (far beyond "You’re just depressed because of the pain" or "You just have migraine because you’re so pessimistic"!).
For more on the study, read Shared genetic factors in migraine and depression: evidence from a genetic isolate., published in January 2010. For more on heritability, check out this brief description.