Association between stress intensity and headache frequency

Background: According to the WHO headache disorders are a public-health concern given the large amount of associated disability and financial costs to society. Headache disorders result in personal and societal burdens of pain, disability, damaged quality of life and high financial costs. However, evidence based knowledge about headache triggering factors is lacking. Especially studies are missing, evaluating the effect of stress on headache frequency with regard to subtypes of headaches. Therefore we studied the effect of stress intensity on headache frequency for the main headache subtypes tension type headache (TTH), migraine and migraine with coexisting TTH using data of a prospective population-based cohort study. Methods: We analysed data of the German Headache Consortium Study including 5,159 participants aged 21 – 71 years, screened quarterly from 2010 – 2012, using validated questionnaires. Headache subtypes were defined according to the criteria of the International Headache Society. Poisson log-linear regression in the framework of Generalized Estimating Equations was used to investigate the effect of stress intensity (visual analogue scale from 0 – 100%) and headache frequency (0 – 30/31 days/month) on different headache subtypes by estimating percent change with 95% confidence intervals (95% CI), adjusting for gender, age and frequent intake of acute pain drugs, drinking, smoking and body mass index. Results: At baseline, TTH was observed in 1,598 (31%) participants (aged 48.1 ± 12.5 years, 51.5% women) with self-reported 2.2 ± 3.9 mean headache days/month, and a mean stress intensity of 52.3%± 26.7%. Participants with migraine (14.0%) were on average younger (44.8 ± 11.3 years), more often women (73.3%) and reported a higher frequency of headaches (4.5 ± 5.2 days/month) and a higher stress intensity (62.4%± 23.3%). Similar results could be observed for those with migraine with coexisting TTH (10.6%, 43.5 ± 11.5 years, 61% women), however with a lower frequency of headaches (3.6 ± 4.8 days), and stress intensity (58.6%± 24.1%) in 19.9% of the participants the headache type was not classifiable. During follow up, participants experienced an increase of headache frequency with increasing stress intensity independently of headache subtype. Notably, highest effects were observed in participants with TTH: a 10% increase of stress intensity resulted in a 6.2% (95% CI: 4.2 – 8.1%) increase of headache days/month. In participants with migraine and in participants with migraine with coexisting TTH the increase was identical with an increase of resp. 3.9% (2.0 – 5.8%) and 4.0% (1.8 – 6.2%). Conclusion: This is the first prospective population-based cohort study which shows that increasing stress resulted in increasing headache days, which was particularly pronounced in participants with TTH. Consideration of these findings is of importance for tailored anti-stress treatment approaches in headache patients with different subtypes of headaches.