LOS ANGELES – Chronic migraineurs reported a greater number of stressful major life events than did those with episodic migraines in a large, cross-sectional analysis of the American Migraine Prevalence and Prevention Study.

In the study, 551 chronic migraineurs were 25% more likely report to a higher number of stressful major life events in the past year than were 7,644 episodic migraineurs, after other factors were taken into account.

"We don’t know whether the events occurred before the onset of chronic migraine or because a person was a chronic migraineur," acknowledged Aubrey N. Manack, Ph.D., an epidemiologist with Allergan Inc.

"What I think is most relevant for clinical practice is that events are perceived as stressful based on an individual’s appraisal," she continued; "so cognitive behavioral interventions may be beneficial in helping individuals reframe their perception of events and in teaching more coping skills."

She recommended future study to assess whether this association is influenced by cultural factors, as well as longitudinal research to determine if stressful life events are a risk factor for or a consequence of chronic migraine.

Session attendee Dr. Gretchen Tietjen of the University of Toledo (Ohio) Medical Center noted that she and her colleagues have analyzed data from the AMPPS as well, and found that early stressful life events – in this case, childhood maltreatment – predicted more frequent headache-days. "So I think an interesting thing would be, besides controlling for all of the things you have controlled for, to look at that, since we already have the data, just to see how many of those chronic migraineurs who had perceived stressful life events had very stressful early life events," she said at the annual meeting of the American Headache Society.

Dr. Manack agreed. And Dawn Buse, Ph.D., a psychologist at the Albert Einstein College of Medicine, New York, and a coinvestigator on both studies, noted that "early stressful life events and traumatic events such as abuse and maltreatment actually in kind of an epigenetic sort of way change our responses forever – immune system responses, coping stress mechanisms. It’s very likely that individuals who had early trauma perceive an event as stressful or overwhelming compared to an individual who had a healthier childhood and who may be more hearty."

"And what’s so interesting to remember is that an event in itself inherently is not stressful," rather it is how a person perceives the event, Dr. Buse added. Therefore, "we need to help our patients perceive life events as manageable and enhance coping skills."

In the longitudinal, population-based AMPPS, questionnaires were mailed to 24,000 individuals reporting severe headache who were first identified in 2004 and then followed up annually between 2005 and 2009.

Dr. Manack’s team studied participants in 2007 who met the diagnostic criteria for migraine, and split them into an episodic migraine group (defined as having fewer than 15 headache-days monthly) and a chronic migraine group (15 or more headache-days monthly).

The participants were surveyed about major life events in the past year, including moves; changes in the status of significant relationships; work and school stressors; events related to children; deaths; and other extremely stressful situations. Those who reported experiencing at least one such event were asked to rate its stressfulness on a 1-5 scale, and events were classified as stressful if they were rated as at least 4.

Overall, 82% of patients with chronic migraine and 79% of patients with episodic migraine reported experiencing at least one major life event in the previous year.

"The difference doesn’t seem that significant, but when you look at ... the number of events that happened, you start to see greater separation," Dr. Manack noted.

Relative to their counterparts with episodic migraine, patients with chronic migraine had higher odds of reporting a greater number of major life events in unadjusted analysis (odds ratio, 1.19; P = .03) and even more so after adjustment for age, sex, race, and body mass index (OR, 1.22; P = .01).

Overall, 77% of patients with chronic migraine and 71% of patients with episodic migraine reported experiencing at least one stressful major life event in the previous year. Again, differences between groups appeared somewhat greater at higher numbers of events.

Relative to their counterparts with episodic migraine, patients with chronic migraine had higher odds of reporting a greater number of stressful major life events in both unadjusted analysis (OR, 1.25; P = .02) and adjusted analysis (OR, 1.26; P = .01).

Dr. Manack disclosed that she is a full-time employee of Allergan Inc. The AMPPS is funded through a research grant to the National Headache Foundation from Ortho-McNeil Neurologics Inc.; additional analyses and manuscript preparation were supported through a grant from Allergan Inc. to the National Headache Foundation.

Chronic Migraine Linked to More Stressful Life Events