Migraine and Major Depressive Disorder (MDD) are highly prevalent conditions that can lead to significant disability. These conditions are often comorbid, and several studies shed light on the underlying reasons for this comorbidity. The purpose of this review article is to have a closer look at the epidemiology, pathophysiology, genetic and environmental factors, temporal association, treatment options, and prognosis of patients suffering from both conditions, to allow a better understanding of what factors underlie this comorbidity. Studies show that patients with migraine are 2-4-times more likely to develop lifetime MDD, predominantly due to similar underlying pathophysiologic and genetic mechanisms. There appears to be a bidirectional temporal association between the two conditions, although longitudinal studies are needed to determine this more definitively. Quality-of-life and health-related outcomes are worse for patients that suffer from both conditions. Thus, a careful assessment of the patient with access to appropriate resources and follow-up is paramount. Future studies in genetics and brain imaging will be helpful in further elucidating the underlying mechanisms in these comorbid conditions, which will hopefully lead to better treatment options.
Keywords: Migraine; comorbidity; depression; epidemiology; major depressive disorder.