To Örebro University

Chronic pain is common and a burden for both the individual and society. In chronic pain, the pain has lost its function as a warning system and instead has become a disease in itself. Neurobiologically, several areas of the brain are involved, but to gain a broader understanding of the long-term pain, the biopsychosocial model is the best starting point. In line with thisand many scientific studies since the late 90's, psychological factors have proven to be an important factor in the development and maintenance of chronic pain. Interdisciplinary multimodal rehabilitation programs (IMMRP) are the treatment currently given to patients with long-term pain in the specialized pain rehabilitation. When the IMMRP has been reviewed, patients have shown improvement over time, but it is not possible to say whether it is the IMMRP or which parts of the IMMRP that explain the improvement (1).

In this licentiate thesis, I have studied the importance of psychological factors in the rehabilitation of patients with chronic pain. This has been done in three studies reported in three published articles. All the studies have been close to the clinic and have been performed on patients in the specialized pain rehabilitation care in Sweden.

The first article studied the effect of the multimodal investigation (MMI). More specifically, it was investigated whether alliance building and feelings of validation in patients with chronic pain affected their acceptance of pain, pain management, catastrophic thoughts, and depression. This was performed in a "single case" study on six patients in MMI. The results showed that despite good alliance and sense of validation, acceptance increased only in one patient and no improvement was seen in pain management, catastrophizing, and depression.

In study two, subgroups of patients with chronic pain were studied. The subgroup analysis showed that patients referred for IMMRP could be divided into groups with different profiles regarding emotional problems and pain avoidance. These profiles were important for how the patients relatedto their pain and the results of IMMRP. The results of the study can increase the understanding of which patients should be selected for IMMRP and how the treatment can be adapted to the patients' needs.

In study three, opioid treatment in patients with long-term pain who were referred to IMMRP was studied. The result showed that opioid prescribing was common and 55% of the participants received at least one prescription for opioids during the two years after the first assessment. It also turns out that there was a connection between individual patient characteristics (especially pain and depressive symptoms) and opioid prescription. Understanding how individual patient characteristics relate to prescribing patterns and long-term opioid use is an important prerequisite for managing opioid prescribing and the basics for preventing overuse. Overall, this licentiate thesis shows that MMU has no therapeutic effect on patients with long-term pain. It also shows that patients with chronic pain are a heterogeneous group that can be divided into subgroups based on psychological characteristics. The subgroups, in turn, had different ways of managing their pain and absorbing the treatment offered. In addition, it emerged that opioid prescribing was common among patients with long-term pain and that there was a link between opioids and patient characteristics.