title: Psychological factors and the development of chronic pain.
abstract: OBJECTIVE
  What is the role of psychological factors in chronic pain and chronic pain disability?
  
  
  METHODS
  The literature search identified 20 observational studies to provide evidence about this question.
  
  
  RESULTS
  Most studies evaluated psychological variables as predictors of return to work. Most studies were prospective cohort studies, including those providing the most data about etiology. In some studies, weak methods and analyses limited the conclusions. In addition, the methodologic criteria of the literature search excluded some well-known reports about this subject.
  
  
  CONCLUSIONS
  Because of the small number of studies, there was inadequate evidence that chronic pain results from a prior psychiatric disorder (level 4a). The studies provided limited evidence (level 3) that chronic depression plays a role in the development of new pain locations (although not for low back pain); that prior nervousness and past negative life events predict work disability; and that depression, anxiety, and a sense that control rests outside of one's own self may predict slower recovery from pain and disability. These findings do not prove that psychological factors have a role in the development of chronic pain. Psychological impairment may precede the onset of pain. Based on current knowledge, it may also arise as a complication of chronic pain.
authors.affiliation: Department of Psychiatry, University of Toronto, Ontario, Canada. klaus.kuch@sympatico.ca
authors.forename: K
authors.initials: K
authors.lastname: Kuch
mesh_terms: D002908:Chronic Disease; D003863:Depression / Q000150:complications / Q000209:etiology; D006233:Persons with Disabilities; D005544:Forecasting; D006801:Humans; D010146:Pain / Q000503:physiopathology* / Q000523:psychology*; D011584:Psychology