BOSTON – Children aged 5-12 years with signs of migraine headache were as much as seven times as likely as other children to also appear to have attention-deficit/hyperactivity disorder (ADHD), but those with tension-type headaches didn’t face a higher risk of ADHD, a Brazilian study showed.
It’s not clear why the apparent link between migraines and ADHD exists. However, lead study author Marco Antônio Arruda, MD, PhD, a pediatric neurologist in São Paulo (Brazil) University, said in an interview that other research has linked migraine to mental health problems.
The , presented at the annual meeting of the American Academy of Neurology and published online in the Journal of Attention Disorders (2017. ), was launched to better understand the connection between migraine and ADHD, which are thought to each affect as many as 1 in 10 children.
The study analyzes data from mothers and teachers of 5,671 children aged 5-12 years who answered questions as part of a Brazil-wide epidemiologic study called the Attention Brazil Project. Just over half of the participants were boys, and about half were from the Brazilian middle class.
Based on answers from mothers and teachers, the researchers estimated that 9% of the children had episodic migraine and 0.6% had chronic migraine. The level of episodic tension-type headache was estimated at 12.8%, with a lower rate in the two poorest vs. the two richest quintiles (8.6% vs. 14.4%, respectively; relative risk, 0.6; 95% confidence interval, 0.5-0.8).
The researchers estimated that 5.3% of the children overall showed signs of ADHD (7.5% in boys vs. 3.1% in girls; RR, 2.4; 95% CI, 1.9-3.1).
There was no sign that children with tension-type headaches had a significantly higher risk of ADHD than other children. However, compared with controls, those with various types of migraine headaches did have a higher risk of ADHD. Nearly 11% of those with migraine overall showed signs of ADHD, compared with 2.6% of the control group (RR, 4.1; 95% CI, 2.7-6.2). The numbers for episodic migraine were nearly identical to those for migraine overall: 10.2% vs. 2.6% (RR, 3.8; 95% CI, 2.5-5.9).
Just over 19% of kids in a third migraine group – those with chronic migraine, defined as headaches appearing more than 14 days per month for the last 3 months – showed signs of ADHD, compared with just 2.6% of the control group (RR = 7.3; 95% CI, 3.5-15.5).
“A number of risk factors to the association were identified, including male gender, prenatal exposure to tobacco, high headache frequency, and below average school performance,” Dr. Arruda said. “However, we did not find a significant influence of age, race, city density, national region where a child lives, income class, and prenatal exposure to alcohol in the comorbidity of ADHD and migraine in this sample. These results help us to identify risk groups allowing early interventions.”
Regarding an explanation for the links between migraines and ADHD, Dr. Arruda pointed to genetic and epigenetic factors that affect brain neurotransmitters and said he believes that stress and other stimuli could be influencing dopamine and noradrenergic processes.
Dr. Arruda said his next step is to examine whether stimulant drugs – the class used to treat ADHD – may help reduce headaches too.
“My clinical experience strongly indicates that psychostimulants have a highly positive effect on migraine prophylaxis, although headache occurs in the very beginning of the treatment,” Dr. Arruda said. “So, we are looking for financial support to conduct a randomized, double-blind, placebo control study to check this hypothesis.”
The study received no specific funding, and Dr. Arruda reported no relevant financial disclosures.