How Does Mindfulness-Based Cognitive Therapy Work?

Mindfulness-Based Cognitive Therapy (MBCT) has demonstrated it reduces depressive relapse in those with three or more depressive episodes across several studies now. But why--what changes occur in MBCT that reduce relapse? The theory behind MBCT suggests increased mindfulness leads to reduced chance of relapse; however, treatments may be effective for reasons having little to do with why we think they're effective.

A recent article by Kuyken and colleagues examines processes of change in MBCT in order to assess the theory behind underlying it. The researchers used what are called mediational analyses. Mediational analyses look at whether changes in one factor (e.g., mindfulness) lead to changes in another (e.g. lower depression).

The authors used data from a previous study (Kuyken et al., 2008) in which 123 people with 3 or more depressive episodes who were currently prescribed antidepressant medication were randomly assigned to either 8-weeks of MBCT or were placed on a wait list. Those in the MBCT condition were weaned off their medication while those not assigned to MBCT remained on their meds. Participants were assessed every 3 months up to a 15 month follow-up. (In the original study, there was no difference in rate of relapse between MBCT and antidepressant meds; however, people in MBCT exhibited fewer depressive symptoms by the 15-month follow-up.)

Results of this study suggest increases in mindfulness and self-compassion mediated the effect of MBCT on depressive symptoms at follow-up. Researchers also looked at what they called cognitive reactivity. Cognitive reactivity was defined as changes in depressive thinking before and after a short piece of "sad" music (i.e., Prokofiev).

Curiously, people who participated in MBCT exhibited greater cognitive reactivity than those who remained on antidepressant medication. Here's the interesting part, though: whereas cognitive reactivity was associated with poorer outcome for people taking antidepressants, participation in MBCT appears to erase this relationship. Said another way, for people who participated in MBCT, cognitive reactivity no longer appeared to impact depressive symptoms. This reminds me of the Mindfulness-Based Relapse Prevention study in which the researchers found the relationship between depression and relapse appeared to disappear for those who participated in the program.

These results of the current study offer further evidence that mindfulness doesn't change patterns of thinking so much as it changes how people relate to thinking. Additionally, this is another study showing the useful in self-compassion in understanding mechanisms of change in mindfulness based treatments. (For another study indicating the importance of self-compassion, click here.)

As with any study, there are limitations. Mediational analyses don't definitively tell us that particular variables lead to change. However, the results largely supported the hypotheses of the researchers, offering additional evidence in support of the theory.

To download a copy of the article, click on the full citation below:

Kuyken, W., Watkins, E., Holden, E., White, K., Taylor, R.S. et al. (2010). How Does Mindfulness-Based Cognitive Therapy Work? Behaviour Research and Therapy, 48, 1105-1113.