Putting mindfulness-based cognitive therapy to the test in routine clinical practice: A transdiagnostic panacea or a disorder specific intervention?

Over the past two decades there has been a growing number of randomized clinical trials supporting the efficacy of mindfulness-based cognitive therapy (MBCT) in the treatment of several psychiatric disorders. Since evidence for its effectiveness in routine clinical practice is lagging behind, we aimed to examine adherence, outcome and predictors of MBCT in a well-characterized, heterogeneous outpatient population in routine clinical practice. Data were collected from a naturalistic uncontrolled cohort of 998 patients formally diagnosed with mainly depression, anxiety disorders, personality disorders, somatoform disorders and/or ADHD. Patients received protocolized MBCT and completed self-report questionnaires pre- and post-treatment on overall functioning (Outcome Questionnaire, primary outcome), depressive symptoms, worry, mindfulness skills and self-compassion. Pre-to post-treatment changes were analysed for the overall sample and each diagnostic category separately with paired sample t-tests, reliable change indices (only overall sample) and repeated measures ANOVA for groups with and without comorbidity. Multiple linear regression was carried out to assess possible predictors of adherence and change in overall functioning. Adherence was high (94%) but negatively affected by lower levels of education, more comorbidity and presence of ADHD. Outcome in terms of improvement in overall functioning was good in the overall sample (Cohen's d = 0.50, 30% showed reliable improvement vs. 3.5% reliable deterioration) and within each diagnostic category (Cohen's d range = 0.37–0.61). Worse overall functioning at baseline was the only predictor for a larger treatment effect. After MBCT, overall functioning improved in a large heterogeneous psychiatric outpatient population independent of diagnosis or comorbidity. •Overall functioning improved after MBCT in a large, heterogenous psychiatric outpatient population.•Medium to large improvements in overall functioning were found, notably with similar effects across diagnostic categories.•Specific diagnostic categories nor other investigated moderators, except baseline severity, influenced treatment efficiency.•Adherence to MBCT was satisfactory in general, although comorbidity, lower levels of education and ADHD decreased adherence.