Can Yoga or Physical Therapy for Chronic Low Back Pain Improve Depression and Anxiety Among Adults From a Racially Diverse, Low-Income Community? A Secondary Analysis of a Randomized Controlled Trial

Abstract

Objective: To determine and compare the effect of yoga, physical therapy (PT), and education on depressive and anxious symptoms in patients with chronic low back pain (CLBP).

Design: Secondary analysis of a randomized controlled trial.

Setting: Academic safety net hospital and 7 community health centers.

Participants: A total of 320 adults with CLBP.

Intervention: Yoga classes, PT sessions, or an educational book.

Outcome measure: Depression and anxiety were measured using the Patient Health Questionnaire and Generalized Anxiety Disorder 7-item Scale, respectively, at baseline, 12, and 52 weeks. We identified baseline and midtreatment (6-wk) factors associated with clinically meaningful improvements in depressive (≥3 points) or anxious (≥2 points) symptoms at 12 weeks.

Results: Participants (female=64%; mean age, 46.0±10.7 years) were predominantly non-White (82%), low-income (<$30,000/year, 59%), and had not received a college degree (71%). Most participants had mild or worse depressive (60%) and anxious (50%) symptoms. At 12 weeks, yoga and PT participants experienced modest within-group improvements in depressive symptoms (mean difference [MD]=-1.23 [95% CI, -2.18 to -0.28]; MD=-1.01 [95% CI, -2.05 to -0.03], respectively). Compared with the education group, 12-week differences were not statistically significant, although trends favored yoga (MD=-0.71 [95% CI, -2.22 to 0.81]) and PT (MD= -0.32 [95% CI, -1.82 to 1.18]). At 12 weeks, improvements in anxious symptoms were only found in participants who had mild or moderate anxiety at baseline. Independent of treatment arm, participants who had 30% or greater improvement in pain or function midtreatment were more likely to have a clinically meaningful improvement in depressive symptoms (odds ratio [OR], 1.82 [95% CI, 1.03-3.22]; OR, 1.79 [95% CI, 1.06-3.04], respectively).

Conclusions: In our secondary analysis we found that depression and anxiety, common in this sample of underserved adults with CLBP, may improve modestly with PT and yoga. However, effects were not superior to education. Improvements in pain and function are associated with a decrease in depressive symptoms. More research is needed to optimize the integration of physical and psychological well-being in PT and yoga.

Trial registration: ClinicalTrials.gov NCT01343927.

Keywords: Anxiety; Depression; Low back pain; Physical therapy modalities; Rehabilitation; Yoga.