A Danish team recruited 29,489 participants from among voluntary blood donors between the ages of 17 and 67, ensuring a large sample size. Participants were asked to complete two simple questionnaires on digital tablets. One asked two questions: “Have you ever had migraine?” and “Have you ever had visual disturbances lasting 5-60 min followed by headache?” A yes to either was considered positive for migraine. The other used the ADHD Self-Report Scale, with 18 ADHD symptoms evaluated on a five-point scale.
Excluding those who did not answer all questions left 26,456 participants. The risk for migraines among those with ADHD was nearly twice the risk for others. The odds ratio (OR) was 1.8, with a 95 percent confidence interval from 1.53 to 2.12 (p < 0.001). The OR was higher among females (2.01) than males (1.64). For those with visual disturbances, the OR was higher (1.98) than for those without (1.52). The association disappeared in those over 60, with an OR essentially equal to one (0.98, 95% CI = 0.84 – 1.15, p = 0.8).
Although the authors concluded, “We demonstrate a significant comorbidity between migraine and ADHD in adults, and this is most prominent for participants with migraine with visual disturbances,” the significance to which they refer are of the p-values, and should not be misinterpreted as an indication of a strong association, as the odds ratios point variably to weak, and weak-to-moderate associations, depending on subpopulations. The work is, however, important as it points to another somatic comorbidity of ADHD. That list is growing and now includes obesity, eczema and asthma.
Thomas Folkmann Hansen, Louise K. Hoeffding, Lisette Kogelman, Thilde Marie Haspang, Henrik Ullum, Erik Sørensen, Christian Erikstrup, Ole Birger Pedersen, Kaspar René Nielsen, Henrik Hjalgrim, Helene M. Paarup, Thomas Werge, and Kristoffer Burgdorf, “Comorbidity of migraine with ADHD in adults,” BMC Neurology (2018), 18:147.