Predicting adherence and clinical response of cognitive behavioral therapy among individuals with chronic low back pain plus depressive symptoms: A secondary analysis of a randomized controlled trial.

Background: Identifying predictors for adherence and clinical response to psychological therapies is essential for improving individual treatment outcomes.

Objective: To explore predictors of adherence and clinical response among individuals with co-occurring chronic low back pain (CLBP) and depression receiving cognitive behavioral therapy (CBT).

Methods: This study employs a secondary analysis of data from a randomized controlled trial (NCT04140838), including 156 individuals with CLBP plus depressive symptoms who received CBT. Multiple linear regression analyses were conducted to assess the predictive power of sociodemographic, health status, pain-related, and therapy-related variables on adherence and clinical response. Adherence was measured by therapy progress (number of completed sessions) and therapy completion (attendance at least six out of eight sessions). Clinical response was assessed by a clinically relevant reduction in posttreatment pain interference.

Results: Older age, higher therapy credibility, and higher education level predicted greater therapy progress, while higher therapy credibility and lower baseline stress levels predicted greater therapy completion. In addition, higher opioid use, baseline pain interference, and baseline depression levels predicted lower clinical response; in contrast, higher behavioral activation levels, older age, and unemployment predicted higher clinical response.

Conclusion: Therapy credibility, age, and education level are key predictors of adherence, and baseline levels of pain interference, depression, and behavioral activation are key predictors of clinical response. These findings may inform opportunities to develop more effective personalized therapeutic plans for individuals with CLBP and depression.