A meta-analysis investigating the prevalence and moderators of migraines among people with bipolar disorder

Background: Uncertainty exists regarding the prevalence and moderators of migraine comorbidity among people with bipolar disorder (BD). We conducted a meta-analysis and meta-regression to investigate the prevalence and moderators of migraine among people with BD.

Method: Two authors independently searched major electronic databases from inception till 02/2015. Articles were included that reported the prevalence of migraine in people with BD with or without a control group. A random effects meta-analysis and exploratory meta-regression were conducted.

Results: Fourteen studies were included encompassing 3976 individuals with BD (mean age 35.5 years, SD 7.6, 29% male). The overall pooled prevalence of migraine was 34.8% (95% CI=25.54-44.69). The prevalence of migraine was higher among people with BD-II (54.17%, 95% CI=31.52-75.95, n=742) compared to BD-I (32.7%, 95% CI=18.16-49.19, n=2138, z=3.97, p<0.0001). The prevalence of migraine was 33.9% (95% CI=26.02-42.44), 39.5% (95% CI=18.81-62.39) and 47.11% (95% CI=22.24-72.77) in North America, Europe and South America respectively. The prevalence of migraine was higher when classified according to recognized criteria at 47.91% (95% CI=32.51-63.5) compared to non-recognized criteria (20.0%, 95% CI=12.44-29.06, z=-8.40, p<0.0001). Meta regression suggests mean age may be a potential moderator.

Conclusion: Migraine is common and burdensome among people with BD. People with BD-II appear to be particularly affected. Nonetheless, future research is required to better understand these relationships, with a special emphasis toward the course specifiers of comorbid migraine cases of either BD-I vs. BD-II.