Mindfulness-based cognitive therapy for patients with chronic, treatment-resistant depression: A pragmatic randomized controlled trial

Cladder-Micus, M. B., Speckens, A. E. M., Vrijsen, J. N., Donders, A. R. T., Becker, E. S. & Spijker, J. (2018). Mindfulness-based cognitive therapy for patients with chronic, treatment-resistant depression: A pragmatic randomized controlled trial. Depression and Anxiety, 35(10), 914-924. https://doi.org/10.1002/da.22788

Summary by: Anne Lisa Weighardt

Chronic and treatment-resistant depression is a serious problem in mental health care. Even if depressed patients receive evidence-based treatment, around 20% still develop a chronic course. This has an impact on both the personal life of a patient and society according to health care costs and workplace losses. New treatment strategies for this specific population are necessary as some patients do not respond to treatment. Cladder-Micus et al. (2018) investigated in their study the effectiveness of Mindfulness-based cognitive therapy (MBCT) + treatment-as-usual (TAU) compared to TAU only for chronically depressed patients. They used a pragmatic, multicenter, randomized-controlled design.

106 patients took part in the study. These patients were chronically depressed, had moderate to high levels of depressive symptoms and had not responded to previous pharmacotherapy and evidenced-based psychological treatments like cognitive behavioral therapy (CBT) or interpersonal therapy (ITP). The participants were randomized to either MBCT + TAU or TAU only. The MBCT condition included eight weekly sessions lasting 2.5 hours each, along with a day of practice. The results were analyzed in two different ways: intention-to-treat (ITT) and per-protocol (PP). The level of depression symptoms as the primary outcome measure was in both analysis in the MBCT + TAU condition lower than in the TAU condition, with small to medium effect sizes. But a significant difference was only found in the PP analyze (–4.24, 95% CI [–8.38 to –0.11], d = 0.45, P = 0.04), not in the ITT analyze (–3.23, 95% CI [–7.02 to 0.56], d = 0.35, P = 0.09) (Cladder-Micus et al., 2018). These results can be partly explained by the relatively high drop-out in the MBCT +TAU condition.

The primary reason for drop-out was physical problems. However, future research should explore the barriers to completing treatment (e.g. by conducting qualitative interviews). A shorter duration of the current depressive episode and a higher unemployment rate reported by non-completers, compared to completers, could indicate the following: a longer duration might heighten psychological burden, which in turn motivates patients to acquire new skills. Compared to TAU, MBCT + TAU had significant effects on the secondary outcomes, which were higher remission rates, less rumination, higher quality of life, more mindfulness skills, and more self-compassion. The improvement in mindfulness skills and self-compassion might indicate that patients with chronic, treatment-resistant depression are capable of acquiring mindfulness meditation techniques and developing a more caring attitude toward themselves. These secondary outcomes should be interpreted preliminary, because of the power analysis focus on changes in depressive symptoms.

However, these results may indicate that even if there are no or only small improvements in depressive symptoms, MBCT + TAU has effects that are beneficial for this severely ill population. Besides the analysis of the effectiveness of MBCT, possible moderators of treatment effect were also analyzed. The moderation analysis showed that patients with high levels of rumination had a significantly larger reduction in depressive symptoms in the MBCT + TAU condition compared to TAU.

This research suggests that MBCT might be especially beneficial for chronic, treatment-resistant depressed patients, who have high levels of rumination. This finding should be considered preliminary and needs replication and further examination. Although the effects of MBCT on depressive symptoms were only significant in the PP analysis, the secondary outcomes showed possible advantages for chronic, treatment-resistant patients. When interpreting the results, it is important to remember that the group of patients is a seriously ill population and therefore even small effects on depressive symptoms associated with effects on rumination, quality of life, mindfulness, and self-compassion could have an impact.