title: Personality traits and sensitivity to pain in male chronic opioid addicts.
abstract: OBJECTIVE
  Previous evidences concerning pain mechanisms, long-term opioids use, and personality traits evolve the possibility that pain perception and opioid abuse are two related phenomena and there is a need to take into account the specific personality traits as well, in examining the relationships among them. Opioid addicts (OAs) have been shown to exhibit different personality traits and pain perception as compared with healthy subjects. The aim of the present study was to examine the relations between personality traits and pain perception among in-treatment OAs in comparison with controls.
  
  
  METHODS
  Participants (54 OAs, 59 controls), all males, were exposed to the cold pressor test and were evaluated for latency of pain onset (seconds); pain intensity (0-100 visual analogue scale [VAS)]); and pain tolerance (time for hand withdrawal). Personality traits were evaluated using Cloninger's Tridimensional Personality Questionnaire, TPQ; harm avoidance, HA; reward dependence, RD; novelty seeking, NS.
  
  
  RESULTS
  In comparison with controls, OAs exhibited longer latencies, lower VAS scores, and shorter tolerance, and significantly higher NS, bigher HA, and lower RD. Control group, but not OAs, showed a significant positive correlation between HA and VAS (r = 0.31, p = 0.02) and significant negative correlation between HA and tolerance (r = - 0.29, p = 0.03).
  
  
  CONCLUSIONS
  It is concluded that in contrast to healthy population, personality traits, as measured by the TPQ, do not predict pain perception in OAs.
authors.affiliation: Pain Relief Unit, Rambam Medical Center, Haifa, Israel.
authors.forename: Elon
authors.initials: E
authors.lastname: Eisenberg
authors.forename: Doron
authors.initials: D
authors.lastname: Cohen
authors.forename: Eli
authors.initials: E
authors.lastname: Lawental
authors.forename: Dorit
authors.initials: D
authors.lastname: Pud
mesh_terms: D016022:Case-Control Studies; D002908:Chronic Disease; D006801:Humans; D008297:Male; D009293:Opioid-Related Disorders / Q000523:psychology* / Q000628:therapy / Q000652:urine; D010146:Pain / Q000523:psychology*; D010147:Pain Measurement / Q000523:psychology*; D010551:Personality; D010556:Personality Tests; D015813:Substance Abuse Detection; D011795:Surveys and Questionnaires