Chronic migraine sufferers tend to be in poorer general health, less well off, and more depressed than those with episodic migraine, reveals research published ahead of print in the Journal of Neurology Neurosurgery and Psychiatry.
The findings are based on almost 12,000 adults with episodic - a severe headache on up to 14 days of the month - or chronic migraine - headache on 15 or more days of the month.
All participants were already part of the American Migraine Prevalence and Prevention (AMPP) study, a long term US population based study of 24,000 headache sufferers, which has included regular surveys since 2004.
The research team analysed data collected in the 2005 survey on socioeconomic circumstances and other health problems.
The results showed that those with chronic migraine had significantly lower levels of household income, were less likely to be working full time, and were almost twice as likely to have a job related disability than their peers with episodic migraine.
They were twice as likely to be depressed, anxious, and experiencing chronic pain. And they were significantly more likely to have other serious health problems.
These included asthma, bronchitis, and chronic obstructive pulmonary disease (COPD), high blood pressure, diabetes, high cholesterol and obesity. They were also around 40% more likely to have heart disease and angina and 70% more likely to have had a stroke.
The authors point out that chronic migraine "can be an especially disabling and burdensome condition."
Previous research indicates that chronic migraineurs have a relatively high level of sick leave, reduced productivity, and poorer quality of family life than episodic migraineurs.
It also suggests that few are diagnosed correctly and that only around one in three are treated appropriately.
The differences unearthed between the two groups in the present study might reflect differences in biological risk factors and provide valuable clues as to how episodic migraine progresses to chronic migraine, suggest the authors.
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