Long-term improvements after mindfulness-based group therapy of depression, anxiety and stress and adjustment disorders: A randomized controlled trial

Background: Although mindfulness-based group therapies (MGTs) for depressive, anxiety or stress and adjustment disorders are promising, there is a substantial lack of knowledge regarding the long-term improvements after such therapies in these common psychiatric disorders. Methods: Two hundred and fifteen patients were randomized in a randomized clinical trial (RCT) (ClinicalTrials.gov ID: NCT01476371) conducted in 2012 at 16 primary healthcare centres in southern Sweden. The patients were randomized to MGT or treatment as usual (TAU) and completed four psychometric self-rated scales after 8 weeks of treatment. Approximately 12months after the completion of the 8-week treatment, the same scales were repeated. Ordinal and generalized linear-mixed models, adjusted for cluster effects, were used for the analysis. Results: For all four psychometric scales (MADRS-S [Montgomery-Åsberg Depression Rating Scale-S], HADS-D, HADS-A [Hospital Anxiety and Depression Scale A and D] and PHQ-9 [Patient Health Questionnaire-9]) the scores at the 1-year follow-up were significantly improved (all P values <0.001) in both groups. Furthermore, there were no significant differences between the MGT and TAU in the psychometric scores at the 1-year follow-up. Conclusions: To the best of our knowledge, this is the first RCT comparing the long-term improvements after MGT with TAU. Although it cannot be excluded that our findings are a result of the natural course of common psychiatric disorders or other factors, they suggest a long-term positive improvement after both MGT and TAU.