A Randomized Controlled Pilot Study on Mindfulness-Based Cognitive Therapy for Unipolar Depression in Patients With Chronic Pain

Abstract

OBJECTIVE: Chronic pain is a disabling illness, often comorbid with depression. We performed a randomized controlled pilot study on mindfulness-based cognitive therapy (MBCT) targeting depression in a chronic pain population. METHOD: Participants with chronic pain lasting ≥ 3 months; DSM-IV major depressive disorder (MDD), dysthymic disorder, or depressive disorder not otherwise specified; and a 16-item Quick Inventory of Depressive Symptomatology-Clinician Rated (QIDS-C₁₆) score ≥ 6 were randomly assigned to MBCT (n = 26) or waitlist (n = 14). We adapted the original MBCT intervention for depression relapse prevention by modifying the psychoeducation and cognitive-behavioral therapy elements to an actively depressed chronic pain population. We analyzed an intent-to-treat (ITT) and a per-protocol sample; the per-protocol sample included participants in the MBCT group who completed at least 4 of 8 sessions. Changes in scores on the QIDS-C₁₆ and 17-item Hamilton Depression Rating Sale (HDRS₁₇) were the primary outcome measures. Pain, quality of life, and anxiety were secondary outcome measures. Data collection took place between January 2012 and July 2013. RESULTS: Nineteen participants (73%) completed the MBCT program. No significant adverse events were reported in either treatment group. ITT analysis (n = 40) revealed no significant differences. Repeated-measures analyses of variance for the per-protocol sample (n = 33) revealed a significant treatment × time interaction (F₁,₃₁ = 4.67, P = .039, η²p = 0.13) for QIDS-C₁₆ score, driven by a significant decrease in the MBCT group (t₁₈ = 5.15, P < .001, d = >1.6), but not in the control group (t₁₃ = 2.01, P = .066). The HDRS₁₇ scores did not differ significantly between groups. The study ended before the projected sample size was obtained, which might have prevented effect detection in some outcome measures. CONCLUSIONS: MBCT shows potential as a treatment for depression in individuals with chronic pain, but larger controlled trials are needed. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01473615.