The Association Between Chronic Back Pain and Psychiatric Disorders; Results from a Longitudinal Population-Based Study

Chronic back pain is a common pain condition; it results in significant personal, social and occupational impairment, role disability and health care utilization.30, 34, 9, 32, 24 Epidemiologic studies have found that chronic back pain is comorbid with psychiatric disorders, other chronic pain conditions (migraine, arthritis, headache) and chronic psychical conditions.26, 15, 30, 5, 13 Most of the published studies regarding the assocation between chronic back pain and psychiatric disorders focus on the association with major depression.30, 5, 21, 22, 4 It is found that the prevalence of major depression among persons with chronic pain is about 2-3 times higher than among pain-free individuals.18 A study conducted by Von Korff et al. (2005) showed that chronic back pain is also significantly associated with mood, anxiety (except agoraphobia without panic) and alcohol abuse and dependence disorders.30 A recent international study conducted by Tsang et al. (2008) found that various chronic pain conditions (headache, back or neck pain, arthritis or joint pain) are associated with depression-anxiety spectrum disorders both in developed and developing countries.29 Although an association between chronic back pain and psychiatric disorders has been repeatedly demonstrated, little is known about the temporal relationship between the two, as most studies are based on clinical samples and cross-sectional data.6 Fishbain et al. (1997) analysed 40 studies addressing the temporal relationship between generic pain and major depression. However, no firm conclusions could be drawn as most of these studies differed in study design, methods and definition to identify depression.11 Fishbain et al. (1997) stated that more support was found for the hypothesis that pain precedes depression, although some of the selected studies found depression to be a predictor of first onset pain.22, 31, 4, 16, 3, 20 The aims of the present study are: 1. To assess cross-sectionally the association between chronic back pain and various mood, anxiety and substance use disorders; 2. To assess longitudinally the temporal relationship between chronic back pain and psychiatric disorders.