title: Alexithymia, depression, inflammation, and pain in patients with rheumatoid arthritis.
abstract: OBJECTIVE
  We previously reported that depression and inflammation have independent effects on pain severity in patients with rheumatoid arthritis (RA). Alexithymia is a personality trait characterized by deficits in cognitive processing and regulation of emotions. A broad association between alexithymia and various health problems has been suggested, including depression, inflammation, and pain. The objective of this study was to examine the independent influence of alexithymia on pain perception and its relationship to depression and inflammation.
  
  
  METHODS
  We evaluated 213 RA outpatients who completed self-administered questionnaires, including the Beck Depression Inventory-II (BDI-II) to measure depression severity, the 20-item Toronto Alexithymia Scale (TAS-20) to measure degree of alexithymia, and a visual analog scale to quantify perceived pain. Serum C-reactive protein (CRP) levels were measured to quantify inflammation severity.
  
  
  RESULTS
  An initial significant positive association between the TAS-20 score and pain severity (P = 0.01) lost significance after controlling for BDI-II score and CRP level using regression analysis. An interaction was observed among alexithymia, depression, and inflammation with regard to perceived pain. Among those without alexithymia, pain severity increased linearly with the CRP tertile levels regardless of the presence of depression (P < 0.001 for trend). No linear association between pain severity and CRP level was observed among those with alexithymia. Moreover, depressed patients with alexithymia (BDI-II score ≥14 and TAS-20 score ≥61) reported severe pain even at low CRP levels.
  
  
  CONCLUSIONS
  Alexithymia might have a substantial role in pain perception as well as depression in patients with RA. A biopsychosocial approach is essential to achieve better pain control.
authors.affiliation: Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Masayo
authors.initials: M
authors.lastname: Kojima
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Kojima
authors.forename: Sadao
authors.initials: S
authors.lastname: Suzuki
authors.forename: Nobunori
authors.initials: N
authors.lastname: Takahashi
authors.forename: Koji
authors.initials: K
authors.lastname: Funahashi
authors.forename: Daizo
authors.initials: D
authors.lastname: Kato
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hanabayashi
authors.forename: Shinya
authors.initials: S
authors.lastname: Hirabara
authors.forename: Shuji
authors.initials: S
authors.lastname: Asai
authors.forename: Naoki
authors.initials: N
authors.lastname: Ishiguro
mesh_terms: D000293:Adolescent; D000328:Adult; D000342:Affective Symptoms / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D003863:Depression / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D011795:Surveys and Questionnaires; D055815:Young Adult