Prevalence of co-morbid bipolar disorder and migraine in a regional hospital psychiatric outpatient department.

Current literature suggests patients with bipolar disorder are at increased risk of developing migraine compared with the general population and patients with other affective disorders. This study examined whether this finding was evident in the outpatient department of a regional psychiatric hospital. Using a patient database (n=1083), records were screened for bipolar disorder (n=169) or self-report of migraine (n=46). 8 cases of co-morbid migraine and bipolar disorder were revealed (4.7% prevalence). This and the general prevalence of migraine (4.2%) are substantially lower than previously reported. Reasons for and implications of this finding are discussed.