Headaches — especially migraines — have less to do with the onset of menstrual periods than previously believed, according to new research in the journal Headache.

Any impact puberty may have on headache occurrence in girls is "diminutive," Dr. Birgit Kroner-Herwig and Dr. Nuria Vath of the University of Gottingen in Germany conclude.

While boys and girls are equally likely to suffer from headaches up to age 12, after that age headaches are more common in girls, and girls are also more likely to experience recurrent headaches, the researchers note in their report. Experts have assumed that puberty in girls may explain this pattern, but little research has followed children and teens over time to determine if this is actually the case.

To investigate, Kroner-Herwig and Vath looked at 2,217 boys and girls aged 9 to 14 who completed questionnaires annually for three years. About a third of the girls had already had their first period before the study began, while another third had not yet menstruated by the end of the study.

Headache risk was about 60 percent higher for girls who began menstruating two or more years previously, the researchers found, although no increase was seen for girls who had their first periods one year before.

When the researchers compared the effects of first menstruation, or menarche, on headache frequency among individuals, they found no evidence that puberty influenced the likelihood of having headaches or migraines.

The researchers also found that 34 percent of boys and 40 percent of girls reported recurrent headaches.

"Our results warn against the rather common overestimation of the role of menarche in headache," the researchers say. "Also, the hypothesis that the occurrence of migraine-type headaches increases with puberty is not supported."

More research is needed to clarify how puberty influences headache risk in girls, they say, adding: "Typical psychosocial challenges and stressors in adolescents during that period of life should be assessed in parallel."