Insomnia in paediatric chronic pain and its impact on depression and functional disability

Background: Children and adolescents attending health care due to chronic pain commonly presents with insomnia. Previous research suggests that problems with sleep are associated with depression and functional disability. However, more research is needed to clarify the relationship between pain, insomnia and disability. Objective: This study aims to investigate the frequency, severity and importance of insomnia in paediatric patients with chronic pain and to evaluate the mediating role of insomnia in explaining the relationship between pain and depression as well as between pain and functioning. In addition, to ascertain the adequacy of using a Swedish translation of the Insomnia Severity Index (ISI) with youths, analyses included a statistical evaluation of the instrument. Method: Correlational analyses of cross-sectional data from 154 consecutive paediatric patients with chronic pain referred to a tertiary pain clinic. Results: Insomnia explained a significant amount of variance in depression and functional disability when controlling for demographic characteristics and pain. Indirect effects of insomnia were found for both the relationship between pain and depression, and between pain and functional disability. ISI showed satisfactory psychometric properties in this sample, including internal consistency and concurrent criteria validity. Conclusions: Insomnia is highly important in explaining depression and functional disability in paediatric chronic pain and can be adequately assessed using the ISI.