FOP differentiates migraineurs from those without headache and plays a significant role in primary headache, particularly in headache-related disability. Findings build upon and extend those from previous chronic pain studies and highlight the need for longitudinal and experimental studies to further explore this construct in headache.

Despite emerging evidence for the comorbidity of posttraumatic stress disorder (PTSD) and migraine, few studies have examined the relation of PTSD and migraine, particularly among clinical populations at-risk for both conditions (e.g., substance-dependent patients). This study examined the role of PTSD symptoms in migraine and headache-related disability within a sample of 153 substance-dependent inpatients (37.25% female, Mean age 36.46). PTSD symptoms predicted both migraine and headache-related disability above and beyond gender, depression and anxiety symptoms, the experience of a Criterion A traumatic event, and current alcohol use disorder. Findings highlight the strong association between migraine and PTSD symptoms in a unique population at risk for both conditions.