Comorbid Migraine in Major Depressive Disorder Suggests a Subgroup Related to Bipolar Disorder

Aims: Previous small-scale studies suggest presence of migraine in major depressive disorder (MDD) is associated with specific clinical characteristics that may overlap with those of bipolar disorder. We aimed to compare a broad range of characteristics in participants who have MDD with and without migraine, and to explore possible similarities between those characteristics associated with the presence of migraine in MDD and those in bipolar disorder in a large UK sample. Methods: Lifetime and episodic clinical characteristics and affective temperaments in DSM-IV MDD with (n=134) and without (n=218) migraine were compared. Characteristics associated with the presence of migraine were then compared with a sample of participants with DSM-IV bipolar disorder (n=407). All participants were recruited into the Bipolar Disorder Research Network (www.bdrn.org). Results: The presence of migraine in MDD was associated with female gender (76.9% vs 56.9%, p<0.001), younger age of onset (23 vs 27 years, p=0.002), history of attempted suicide (38.3% vs 22.7%, p=0.002), and more panic/agoraphobia symptomatology (6 vs 4, p<0.001). Female gender (OR=2.44, p=0.006) and younger age of onset (OR=0.97, p=0.013) remained significant in a multivariate model. These clinical characteristics were not significantly different to those of our participants with bipolar disorder. Conclusions: The presence of migraine in MDD delineates a subgroup of individuals with a more severe illness course. The clinical presentation of this subgroup more closely resembles that of bipolar disorder than that of MDD without migraine. The presence of migraine in major depression may be a marker of a specific subgroup that could be useful in future research.