K. M. Refshauge

The role of depression and catastrophizing in musculoskeletal pain.

Many patients with musculoskeletal pain also suffer from a depressed mood. Catastrophizing is one process that may link depression and pain since it is a key concept in models of both problems. Earlier research has suggested that catastrophizing measures something above and beyond depression. This study tests the idea that if depressed mood and catastrophizing are separate entities then when one is absent the other should still contribute to poor outcome, and, when both are present there should be an additional adverse effect. To this end, a prospective design, with a built-in replication from two clinical samples of patients with sub-acute pain (one from Sweden, N=373; one from Australasia, N=259), was employed. Participants were classified as to having high/low scores on measures of depression and catastrophizing. Subsequently, these classifications were studied in relation to outcome variables cross-sectionally and at follow-up. Results showed a small to moderate correlation between catastrophizing and depression and that there are individuals with one, but not the other problem. Further, having one or the other of the entities was associated with current pain problems and outcome, while having both increased the associations substantially. The replication showed very similar results Our data demonstrate that pain catastrophizing and heightened depressed mood have an additive and adverse effect on the impact of pain, relative to either alone. It suggests that each should be assessed in the clinic and that future research should focus on treatments specifically designed to tackle both depressed mood and catastrophizing.Many patients with musculoskeletal pain also suffer from a depressed mood. Catastrophizing is one process that may link depression and pain since it is a key concept in models of both problems. Earlier research has suggested that catastrophizing measures something above and beyond depression. This study tests the idea that if depressed mood and catastrophizing are separate entities then when one is absent the other should still contribute to poor outcome, and, when both are present there should be an additional adverse effect.

Do Psychological Characteristics Predict Response to Exercise and Advice for Subacute Low Back Pain

OBJECTIVE To determine whether psychological characteristics predict outcome and/or response to physiotherapist-directed exercise- or advice-based treatment of subacute low back pain. METHODS We conducted a secondary analysis of a factorial, placebo-controlled trial (n = 259). The psychological characteristics were catastrophizing, coping, pain self-efficacy, fear of injury/movement, depression, anxiety, and stress. We used mixed models to predict pain and function outcomes (both scored on a 0-10 scale). The models include a term for treatment group, a term for the psychological characteristic (which tested prediction of outcome), and an interaction term between the treatment group and psychological characteristic (which tested treatment effect modification). To aid the interpretation of the magnitude of the effect modification, we calculated the change in outcome for a 1 SD increase of the baseline score of the putative effect modifier. A >/=1.5-point change of the outcome of interest per 1 SD change of putative effect modifier was regarded as clinically important. RESULTS All of the psychological characteristics except coping predicted outcome, but none appeared to be important treatment effect modifiers. Only 5 of the 56 tests of treatment modification were statistically significant, and none of the 95% confidence intervals (95% CIs) for the interactions included clinically important effects. For example, a 1 SD higher baseline level of anxiety was associated with a 0.62 (95% CI 0.10, 1.15) additional effect of exercise on function at 52 weeks. CONCLUSION Most of the psychological characteristics we tested predicted outcome, but none predicted response to physiotherapist-guided exercise and/or advice.