People with specific variants of a body clock gene are more likely than others to develop migraines under financial hardship.
'This work does not show what causes migraine – there is no single cause – but it does show that both stress and genetics have an effect,' said Daniel Baksa at Semmelweis University, Hungary, and first author of the new study.
Scientists from Hungary and the UK studied DNA from 2349 participants from Budapest and Manchester. They looked for two common SNPs (single nucleotide polymorphisms) of the circadian gene CLOCK which, among others, is involved in the regulation of sleep and the major stress hormone, cortisol.
The research found there was no direct effect between the SNPs, present in around a third of the population, and migraines only. However, the odds of developing migraines increased by about 20 percent with these particular gene variants when stress was included in the analysis. Participants filled in a questionnaire on their financial situations to assess this.
Co-author Professor Xenia Gonda of Semmelweis University told Newsweek that 'financial stress was used as a proxy' for chronic stress - as opposed to something that might cause acute stress, like a work deadline.
Professor Andreas Reif at the University Hospital, Frankfurt, who was not involved in the study, said: 'This is a really interesting study on the interaction of genetics with stress in migraine. The studied gene is involved in the circadian system, which has previously been shown to be implicated in mental disorders such as bipolar disorder, which intriguingly is co-morbid with migraine.'
He added that the study might give clues as to how such disease might be linked. He noted: 'But even beyond this, the study demonstrates how an environmental risk factor exerts its effect only in the presence of a given genetic risk factor. This has not been done to a great extent in migraine, making this study an exciting new lead.'
This work was presented at the European College of Neuropsychopharmacology conference in Paris, France.