About 10% of the world population suffers from migraine headaches, according to the National Institute of Neurological Disorders and Stroke. To alleviate migraine pain, people are commonly treated with opioids. But, while opioid treatment can provide temporary pain relief for episodic migraines, prolonged use can increase the frequency and severity of painful migraines.
Researchers have tried to understand how opioids cause this paradoxical increase in pain for a decade, but the mechanism remained elusive — until now.
Researchers at the University of Illinois at Chicago and colleagues discovered that a peptide — small chains of amino acids that can regulate many behaviors and brain signaling pathways — links together migraine pain and pain induced by opioid overuse.