A study of over 2,000 Spanish twins concludes that genetic factors affecting both conditions may be involved in the association between back pain and depression. The study appears in the March issue of PAIN®. Studies of twins afford a unique opportunity to examine the association between health conditions, by eliminating the genetic and environmental factors contributing to them. In this research, questionnaire responses were analyzed to determine whether participants with symptoms of depression had higher prevalence of back pain. A series of statistical analyses were then performed to clarify the contributions of genetic factors and early shared environment to the depression-back pain link.
Previous studies have shown a "consistent relationship" between back pain and depression—a combination that may complicate diagnosis and treatment. However, the nature of the association remains unclear. The new study is the first to examine the relationship between depression and low back pain using twin data to control for genetic and familial factors. A news story about the study, with link to the journal article, may be read here.