Both migraine and dementia are common neurological conditions affecting millions of people and leading causes of disability. Researchers have been looking at possible associations between the two conditions for the past few years. A long-term impact of migraine could be a higher risk of dementia. According to a new study, migraine headaches are a risk factor for dementia later in life, but the risk is particularly high for those who experience migraine with aura.

In the US, an estimated 39 million people are affected by migraines, and about 1 billion globally, and it is the third most prevalent illness in the world. In addition, approximately 50 million people worldwide have dementia, with almost 10 million new cases occurring each year.

Studies have previously reported a link between migraines and a heightened risk of dementia later in life. Still, most of them had smaller populations and did not differentiate between the different types of migraine. For example, a study conducted last year that included 679 community-dwelling adults aged 65 years and older found that participants with a history of migraines were three times more likely to develop any dementia but about four times as likely to develop Alzheimer’s disease.

But in this study, the researchers, led by Sabrina Islamoska, MSc, Ph.D., from the University of Copenhagen, used national register data of individuals born from 1935 to 1956. They then matched people diagnosed at a hospital with any type of migraine between the ages of 31 to 58 years. There were 18,135 individuals in the migraine group and 1,378,346 without a history of migraines.

There were 62,578 people included in their analysis, and the study covered 30 years (1988–2017). The average age for being diagnosed with a migraine was 49 years, and about 70% of the migraine population were women. Beginning at age 60 years, 207 individuals with migraines developed dementia. In the group without migraine, 640 individuals had dementia. The average age for the onset of dementia is similar in both groups; 68 for the migraine group and 69 for those without migraine. Overall, those with a history of migraine had a 50% higher rate of dementia than the rest of the study population. But when separating the group by migraine type, there was a 20% higher rate of dementia in those who had migraine without aura, and it was not statistically significant.

However, when the population with migraine plus aura was evaluated, the dementia rate was twice as high as those without migraine. Frequent hospital visits also resulted in a higher rate of dementia. There was also a slightly higher rate of dementia in women with migraine compared to men with migraine, and a higher rate was observed in individuals with a higher educational level. But these differences did not reach statistical significance.

One limitation of the study, note the authors, is that most migraine cases are treated in primary healthcare in Denmark. National recommendations call for uncomplicated migraine cases to be treated by the patient’s general practitioner, while specialized neurologists or headache units should treat complicated, unsolved, or rare migraine cases. As this study only included migraine cases treated in hospital settings, the less severe and well-managed migraine cases were probably managed in the primary care setting. The exclusion of these patients may lead to an underestimation of the migraine-dementia association. In addition, the prevalence of migraine overall is 16% in Denmark, but in this study, it was only 1.3% (of 1,396,481 individuals), which also potentially underestimates the actual risk of dementia.

“Our findings emphasize the need for studies on the pathophysiology linking migraine with dementia to identify preventive measures,” the authors conclude.