Turns out your mom was right: scratching an itch only makes it worse. New research from scientists at Washington Univ. School of Medicine in St. Louis indicates that scratching causes the brain to release serotonin, which intensifies the itch sensation.
The findings, in mice, are reported online in the journal Neuron. The same vicious cycle of itching and scratching is thought to occur in humans, and the research provides new clues that may help break that cycle, particularly in people who experience chronic itching.