For many individuals chronic pain has adverse consequences on daily activity, employment, relationships, and emotional functioning (Breivik, Collett, Ventafridda, Cohen & Gallcher, 2006). Several studies have investigated the prevalence of chronic pain among adults. Results show that 15–20 percent of adults experience chronic pain. Considering all sources of expenditures, chronic pain has a large financial impact on society (Breivik et al., 2006).
Chronic pain is a demoralizing situation that compromises all aspects of the person's life, including disability and emotional distress. Psychological research has identified the central role of cognitive, behavioural and emotional factors contributing to the perpetuation of chronic pain (Kerns, Sellinger, & Goodin, 2011). Cognitive-behavioural therapy (CBT) delivered in a multidisciplinary setting has been shown in several controlled studies to be effective in the treatment of chronic pain (e.g. Hoffman, Papas, Chatkoff, & Kerns, 2007; Morley, Eccleston, & Williams, 1999). A common factor for the psychologically oriented interventions for chronic pain is that the focus is on the consequences that pain has on one's life, rather than on pain intensity, as a way of directly addressing adaptive behavioural change (Kerns et al., 2011).
In the so called third generation of cognitive behavioural treatments, e.g. acceptance and commitment therapy (ACT), function is emphasized in contrast to form. Behaviour is analysed from a functional perspective, i.e. the aim is to understand why a particular behaviour is maintained rather than describing what kind of behaviour a person performs. In order to understand how influence can affect the function of behaviour it is important to alter the social/verbal context through identification of basic processes that are common across settings (Hayes, Luoma, Bond, Masuda, & Lillis, 2006; Hayes, Strosahl, & Wilson, 1999). From this perspective, chronic pain can be viewed as an experiential avoidance disorder. Experiential avoidance has been defined as attempts to avoid thoughts, feelings, memories, physical sensations, and other internal experiences, which often creates suffering in the long-run (McCracken, Vowles, & Eccleston, 2004; Vowles & McCracken, 2010). Studies have shown that experiential avoidance is associated with higher pain intensity, pain-related anxiety, depression and physical and psychosocial disability (Feldner et al., 2006; McCracken, 1998; McCracken & Vowles, 2006). These results suggest that acceptance of pain and a willingness to abandon the struggle to avoid or reduce pain, will enable the individual to be more present in the moment. Mindfulness exercises, have its roots in Asian religious traditions, help the individual to fully experience the phenomenon in the present moment without the influence of verbal content (Fletcher & Hayes, 2005). Being present in the moment will help the individual distancing from pain-related thoughts and acting in accordance with chosen values (McCracken, 1998; McCracken & Eccleston, 2003; McCracken & Vowles, 2006; McCracken et al., 2004; Wetherell et al., 2011).
A systematic review showed that acceptance based therapies could be an alternative to CBT although the researchers stated that more controlled studies are needed (Veehof, Oskam, Schreurs & Bohlmeijer, 2011). The review included seven ACT-studies and fifteen mindfulness-based stress reduction (MBSR) programs. In addition, ACT has been listed as an empirically supported treatment for chronic pain and depression (APA, 2006/2011).
