CHICAGO, IL - APRIL 14: Pain medications, which contain acetaminophen, are shown on April 14, 2015 in Chicago, Illinois. New research has shown that acetaminophen, which is found in many over-the-counter painkillers, can dull feelings of pleasure. Previous research found that the medication had a similar effect with feelings of dread. (Photo Illustration by Scott Olson/Getty Images)

CHICAGO, IL - APRIL 14: Pain medications, which contain acetaminophen, are shown on April 14, 2015 in Chicago, Illinois. New research has shown that acetaminophen, which is found in many over-the-counter painkillers, can dull feelings of pleasure. Previous research found that the medication had a similar effect with feelings of dread.  (Photo Illustration by Scott Olson/Getty Images)