The goal of this research project is to explore if levels of inflammation predict levels of comorbid mood disorders and treatment success in chronic pain patients. More knowledge in this respect will advance our understanding of chronic pain and comorbid syndromes, and facilitate subgroupings of patients based on the presence and/or level of low-grade inflammation. This research is an important step towards finding an explanation to why treatment effects following behavioral interventions differ across individuals, and generate new hypothesis regarding novel treatment approaches. The specific aims are: 1) to explore if baseline levels of inflammatory biomarkers predict the effects of behavioral intervention and 2) to investigate if baseline levels of inflammatory biomarkers are associated with psychological co-morbidity (e.g. depression, anxiety and fatigue) in patients with chronic pain.

Inclusion Criteria:

1. Referred to a specialist clinic within pain management
2. Equal to or older than 18 years
3. Chronic pain (> 6 months)
4. The pain is refractory
5. The pain results in significant functional limitations
6. Stable medication in the last 2 months and no planned changes in medication (except possibly discontinuation or lowering of current dose)

Exclusion Criteria:

1. Spontaneous improvement can be expected (without treatment)
2. Psychiatric comorbidity a) is deemed to be the main reason for the restrictions, or b) should be promptly evaluated and possibly treated, or c) may adversely affect the treatment given in the context of the study
3. Significant risk of suicide
4. Poor teamwork, defined as repeated missed appointments during the assessment / investigation phase
5. Language difficulties (Swedish)

The patients at the Karolinska Pain Center, suffering from chronic pain that does not respond to any other pain treatments and affects daily functioning severely.