Headache types and panic disorder : Directionality and specificity

To examine the relationship of migraine and other severe headaches with panic disorder. Representative samples of persons with migraine, non-migrainous severe headaches, and controls with no history of severe headaches, identified by a telephone survey, were interviewed in person, using a standardized psychiatric interview. Cox proportional hazards models with time-dependent covariates were used to examine the relationship of headaches with first-onset panic disorder and vice versa. Lifetime prevalence of panic disorder was significantly higher in persons with migraine and in persons with other severe headaches, compared with controls. Migraine and other severe headaches were associated with an increased risk for first onset of panic disorder (hazards ratios = 3.55 and 5.75). Panic disorder was associated with an increased risk for first onset of migraine and for first onset of other severe headaches, although the influences in this direction were lower (hazards ratios = 2.10 and 1.85). Comorbidity of panic disorder is not specific to migraine and applies also to other severe headaches. The influence is primarily from headaches to panic disorders, with a weaker influence in the reverse direction. The bidirectional associations, despite the difference in the strength of the associations, suggest that shared environmental or genetic factors might be involved in the comorbidity of panic disorder with migraine and other severe headaches.