Chronic pain is an unknown issue with unknown causes and a subjective definition but some people clearly have it. Researchers recently analyzed 2,721 people, all taking prescription opioid pain medications, for genes COMT, DRD2, DRD1 and OPRK1. The participants also rated their perception of pain on a scale from zero to 10. People who rated their pain as zero were not included in the study.
Low pain perception was defined as a score of one, two or three; moderate pain perception was a score of four, five or six; and high pain perception was a score of seven, eight, nine or 10.
9 percent of the participants had low pain perception, 46 percent had moderate pain perception and 45 percent had high pain perception.