Depression as a risk factor for onset of an episode of troublesome neck and low back pain.

The objective of this study is to determine whether depression is an independent risk factor for onset of an episode of troublesome neck and low back pain. There is growing evidence that pain problems increase the risk of depression. However, the evidence about the role of depression as a risk factor for onset of pain problems is contradictory. This lack of consistency in research findings may be due in part to methodological weaknesses in existing studies, for example, use of an inappropriate study design and inadequate consideration of confounding. A population-based random sample of adults was surveyed and followed at 6 and 12 months. Individuals at risk of troublesome (intense and/or disabling) neck or low back pain are the subjects of this report (n=790). We used Cox proportional hazards models to measure the time-varying effect of depressive symptoms on the onset of troublesome neck and low back pain. Our multivariable analysis considered the possible confounding effects of demographic and socio-economic factors, health status, co-morbid medical conditions and injuries to the neck or low back. We found an independent and robust relationship between depressive symptoms and onset of an episode of pain. In comparison with the lowest quartile of scores (the least depressed), those in the highest quartile of depression scores had a four-fold increased risk of troublesome neck and low back pain (adjusted HRR 3.97; 95% CI 1.81-8.72). Depression is a strong and independent predictor for the onset of an episode of intense and/or disabling neck and low back pain.