Allergy medications can do more than clean a stuffy nose, says new report this shows that diphenhydramine – the antihistamine of Benadryl – prevents the recall of aversive negative memories in humans.
Haunting memories are an important feature of post-traumatic stress disorder (PTSD), which affects 7.7 million people in the United States, according to the National Institutes of Health. But not everyone who goes through a traumatic experience will suffer from recurring and painful memories.
Subtle traits in a person’s genome may be involved, according to this report from geneticists at the University of Basel, Switzerland.
The researchers compared the genomes of 2,500 healthy young volunteers after completing an emotional memory performance test. The team discovered a group of genetic traits that were more common in people who had an easier time remembering negative memories.
Then the scientists cross-checked that list of traits with a catalog of approved drugs to see if any of the first could be manipulated clinically. They chose to remove compounds that could trigger serious side effects and went ahead with a smaller set of nine gene-drug pairings.
These nine traits were again examined in biological data from a second group of 340 Holocaust survivors to narrow the subset to a genetic target strongly linked to traumatic memory.
The final winner was the histamine H1 receptor (HRH1) gene, overstimulation of which with allergies contributes to runny nose and asthma.
To test whether antihistamines could thwart negative memories, 40 people took diphenhydramine and underwent a test where they were asked to recall upsetting events. Diphenhydramine significantly reduced recall of negative memories, but had no effect on positive or neutral memories.
âThe rapid development of innovative methods of genetic analysis has made this new and promising approach possible,â said co-lead author and professor Andreas Papassotiropoulos of the University Psychiatric Clinics at the University of Basel. âIn another study, we will try to identify and develop drugs that improve memory. “
Source: Papassotiropoulos A, Gerhards C, Heck A, et al. Human genome-guided identification of memory-modulating drugs. PNAS. 2013.