Pain catastrophizing as a treatment process variable in cognitive behavioural therapy for adults with chronic pain.

Abstract

Interdisciplinary cognitive behavioural therapy (CBT) for chronic pain is effective at improving function, mood and pain interference among individuals with disabling chronic pain. Traditionally, CBT assumes that cognitive change is an active therapeutic ingredient in the determination of treatment outcome. Pain catastrophizing, a cognitive response style that views the experience of pain as uncontrollable, permanent and destructive, has been identified as an important maladaptive cognition which contributes to difficulties with the management of chronic pain. Consequently, pain catastrophizing is commonly targeted in CBT for chronic pain. To examine change trajectories in pain catastrophizing during treatment and assess the relevance of these trajectories to outcomes at posttreatment. Participants included individuals with chronic pain (N=463) who completed a 3-week program of interdisciplinary CBT. Pain catastrophizing was assessed weekly over the 3weeks of treatment and latent growth curve modelling was used to identify trajectories of change. Findings indicated the presence of two classes of linear change, one with a significant negative slope in pain catastrophizing (i.e. improved class) and the other with a non-significant slope (i.e. unchanged class). Next, latent growth mixture modelling examined treatment outcome in relation to class membership. These results indicated that individuals in the 'improved' PCS class had significantly greater improvement in pain interference and mood, as well as physical and mental quality of life compared to the 'unchanged' class. Implications for our findings, in relation to the CBT model, are discussed.