Lumbar Spine Pathology, Depression, and Psychiatric Disorders (A 53-Year Prospective Study of 1337 Patients)

Johns Hopkins Department of Orthopaedic Surgery, Baltimore, Maryland, USA

Introduction:
The relationship between depression and low back pain (LBP) has been extensively studied. Some authors have described a "back pain personality" which includes depression and personality disorders which may be a causative factor in generating LBP. Others feel that the depression and personality disorders result from a reaction to the disease itself. This study was undertaken to determine whether an association exists between psychiatric disorders such as depression and lumbar spine pathology. That this study is prospective with long follow-up also enabled us to determine whether depression preceded the lumbar spine disease. If so, this would suggest that psychological factors may be causative in the development of LBP.

Materials and Methods:
1337 graduates from the medical school classes from 1948-1964 at our institution were consented to participate in a longitudinal study which started in 1949. All volunteers had records and questionnaires sent in each year. The onset of depression and other psychiatric disorders was recorded for each subject if present. Similarly, the onset of chronic LBP, lumbar spondylosis, and/or lumbar HNP was recorded for each subject. Logistic regression analyses were used to determine if a relationship existed between depression and/or psychiatric disorders and chronic LBP, lumbar HNP, and lumbar spondylosis. Finally, only cases in which the depression or psychiatric illness preceded the lumbar spine disease were included and the analyses were repeated.

Results:
Depression was significantly associated with chronic LBP (p=0.02) and lumbar spondylosis (p=0.04). There was no association between other psychiatric disorders and lumbar spine disease. When we considered only subjects in whom the depression or psychiatric disorder preceded the lumbar spine disease, neither depression nor other psychiatric illnesses were significantly associated with the future development of lumbar spine disease.

Conclusion:
A significant association was noted between depression and chronic LBP and between depression and lumbar spondylosis. However, this association disappeared when we considered only those cases in which the depression preceded the onset of lumbar spine disease. This suggests that the depression that is frequently associated with LBP and lumbar degenerative disease is a consequence of the lumbar spine disease process rather than a cause of the disease. Thus, the theory that a depressive "back pain personality" is responsible for development of LBP and lumbar spine disease is unlikely to be valid.