Bidirectionality between pain and insomnia symptoms: a prospective study.

OBJECTIVES: The purpose of this study was to investigate whether there is a bidirectional relationship between pain and insomnia symptoms over the course of a year.
DESIGN: A longitudinal design with a 1-year follow-up was used.
METHODS: From a randomly selected sample of the adult general population (N= 3,000), 1,746 individuals filled out a baseline and 1-year follow-up survey on pain, insomnia symptoms, anxiety symptoms, and depressive symptoms.
RESULTS: Pain (OR = 1.64) and anxiety symptoms increased the risk for the incidence of insomnia symptoms (R(2) = .125) and pain (OR = 1.98), anxiety symptoms and depressive symptoms were related to the persistence of insomnia symptoms (R(2) = .212). Gender and anxiety symptoms increased the risk for the incidence of pain (R(2) = .073); and age, insomnia symptoms (OR = 1.49), anxiety symptoms, and depressive symptoms were associated with the persistence of pain (R(2) = .187).
CONCLUSION: While pain was linked to future insomnia symptoms and insomnia symptoms to the persistence of pain over the course of a year, insomnia symptoms was not associated with the incidence of pain. The results, thus, partly argue against bidirectionality between pain and insomnia symptoms. ©2011 The British Psychological Society.