The relationship between pain and depressive symptoms after lumbar spine surgery.

Although depressive symptoms are common among those living with back pain, there is limited information on the relationship between postsurgical pain reduction and changes in depressive symptoms. The objective of this prospective cohort study was to examine the change in pain and depressive symptoms and to characterize the relationship between pain and depressive symptoms after lumbar spine surgery. We assessed 260 individuals undergoing lumbar spine surgery preoperatively and postoperatively (3 and 6 months) using a pain intensity numeric rating scale and the Patient Health Questionnaire depression scale. The relationship between change in pain (a 2-point decrease or 30% reduction from the preoperative level) and depressive symptoms was examined using standard regression methods. Preoperatively, the mean pain intensity was 5.2 (SD 2.4) points, and the mean depressive symptom score was 5.03 (SD 2.44) points. At 3 months, individuals who experienced a reduction in pain (63%) were no more likely to experience a reduction in depressive symptoms (odds ratio 1.07, 95% confidence interval [CI] .58 to 1.98) than individuals who experienced no change from preoperative pain (34%). However, at 6 months, individuals who experienced a reduction in pain (63%) were nearly twice as likely to experience a reduction in depressive symptoms (odds ratio 1.93, 95% CI 1.15 to 3.25) as those who experienced no change or an increase in pain (31%). We found that most individuals experienced clinically important reductions in pain after surgery. We concluded that those whose pain level was reduced at 6 months were more likely to experience a reduction in depressive symptoms.