What Causes Migraines? Scientists Discover Chemical Imbalance That Might Be Behind Severe Headaches

Migraines are especially painful type of headache and the true cause remains unclear. MONEY SHARMA/AFP/Getty Images

Migraine sufferers who become depressed or anxious during headache spells are not imagining the connection. A new study found that all three conditions may be due to the same chemical imbalance, a discovery that could lead to better treatments for migraines.

Past research has suggested links between depression, anxiety and the propensity to have more intense migraines. But the exact nature of that connection—and whether it definitely existed—was unclear. For the new study, published in Headache, researchers from the National Defense Medical Center looked at 409 patients who had sought for treatment for their frequent migraines. The researchers noted a number of demographic and clinical characteristics of the patients, as well as 179 controls. The researchers found a direct link between migraine frequency and depression and anxiety severity. No other characteristics—including gender, the presence of auras (sensory disturbances, usually visual) accompanying migraines, alcohol and coffee—influenced migraine frequency.

The new study, confirmed that regardless of any other factors, individuals who have migraines are more likely to have worse symptoms of anxiety and depression. It does not seem as though one necessarily causes the other, but rather that migraines influence depression and anxiety.

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The confirmed link between these three conditions could "These findings potentially suggest that adequate medical treatment to decrease headache frequency may reduce the risk of depression and anxiety in migraine patients," said Fu-Chi Yang, study author and a neuroscientist with Tri-Service General Hospital, National Defense Medical Center, Taiwan, in a press release.

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The researchers offered some thoughts for why emotional distress could be linked to migraines. They theorize that serotonin, a chemical produced by the nervous system is less active when a person experiences a number of migraines. Diminished serotonin lowers the pain threshold, making a person more sensitive to pain (resulting in more severe migraines) ands play a well-known role in depression and anxiety.

Migraines are different from the average headache. The cause is still uncertain, but having some more clues about the emotional and psychological connection may be of some comfort.