Objectives: To determine whether baseline anxiety and social stressors as well their early change (first 3 months) predict 12-month depression and pain severity.
Methods: We analyzed data from the Stepped Care for Affective Disorders and Musculoskeletal Pain study, a randomized clinical trial of a combined medication-behavioral intervention for primary care patients with chronic musculoskeletal pain and depression. Using multivariable linear regression modeling, we examined the independent association of baseline anxiety and social stressors with depression and pain severity at 12 months. In addition, we modeled whether changes in anxiety and social stressors predicted 12-month depression and pain severity.
Results: Overall, the sample (N=250) was 52.8% women with a mean age of 55.5 years, and a racial distribution of 60.4% white, 36.4% black, and 3.2% other. Depression and pain were moderately severe at baseline (mean SCL-20 depression=1.9 and Brief Pain Inventory pain severity=6.15) and similar across intervention and usual care arms. Baseline anxiety symptoms predicted both depression (t score=2.13, P=0.034) and pain severity (t score=2.75, P=0.007) at 12 months. Also, early change in anxiety predicted 12-month depression (t score=-2.47, P=0.014), but not pain. Neither baseline nor early change in social stressors predicted depression or pain severity.
Conclusions: Anxiety, but not social stressors predict 12-month depression and pain severity. The presence of comorbid anxiety should be considered in the assessment and treatment of patients with musculoskeletal pain and depression, particularly as a factor that may adversely affect treatment response.