Gender differences, clinical correlates, and longitudinal outcome of bipolar disorder with comorbid migraine.

Objective: Migraine is a common comorbidity of bipolar disorder and is more prevalent in women than men. We hypothesized comorbid migraine would be associated with features of illness and psychosocial risk factors that would differ by gender and impact outcome.

Method: A retrospective analysis was conducted to assess association between self-reported, physician-diagnosed migraine, clinical variables of interest, and mood outcome in subjects with DSM-IV bipolar disorder (N = 412) and healthy controls (N = 157) from the Prechter Longitudinal Study of Bipolar Disorder, 2005-2010. Informed consent was obtained from all participants.

Results: Migraine was more common in subjects with bipolar disorder (31%) than in healthy controls (6%) and had elevated risk in bipolar disorder women compared to men (OR = 3.5; 95% CI, 2.1-5.8). In men, migraine was associated with bipolar II disorder (OR = 9.9; 95% CI, 2.3-41.9) and mixed symptoms (OR = 3.5; 95% CI, 1.0-11.9). In comparison to absence of migraine, presence of migraine was associated with an earlier age at onset of bipolar disorder by 2 years, more severe depression (β = .13, P = .03), and more frequent depression longitudinally (β = .13, P = .03). Migraine was correlated with childhood emotional abuse (P = .01), sexual abuse (P = 4 × 10⁻³), emotional neglect (P = .01), and high neuroticism (P = 2 × 10⁻³). Protective factors included high extraversion (P = .02) and high family adaptability at the trend level (P = .08).

Conclusions: Migraine is a common comorbidity with bipolar disorder and may impact long-term outcome of bipolar disorder, particularly depression. Clinicians should be alert for migraine comorbidity in women and in men with bipolar II disorder. Effective treatment of migraine may impact mood outcome in bipolar disorder as well as headache outcome. Joint pathophysiologic mechanisms between migraine and bipolar disorder may be important pathways for future study of treatments for both disorders.