An investigation into variables moderating the outcomes of mindfulness meditation

Mindfulness-based Cognitive Therapy’s (MBCT) application has become increasingly widespread following its establishment as an effective treatment for depression relapse prevention. Mindfulness meditation (MM) is an integral component of MBCT, but little research has looked at MM guidance instructions themselves. This study aimed to compare the efficacy of two types of MM instruction in improving state affect, in addition to examining whether the type of instruction interacted with the trait characteristic of self-criticism to influence positive affect specifically. Seventy participants were randomised to groups doing either a concentration-oriented or an acceptance-oriented 10-minute MM of the breath. Changes between the groups in pre- to post-meditation state affect, state mindfulness and state concentration were analysed using a three-way mixed ANOVA, with baseline self-criticism entered as a between-participant variable to investigate its hypothesised interaction (or, moderation) with meditation type and outcomes across time.

Significant improvements in mindfulness, concentration and negative affect were seen across both meditations, with the concentration-oriented meditation improving concentration significantly more than the acceptance-oriented condition. Further, those categorised as highly self-critical demonstrated a significant reduction in negative affect compared to no reduction for low self-critical participants. The hypothesised interaction between self-criticism and meditation type was not found. Modifying MM of the breath instructions may hold potential in selectively targeting outcomes such as concentration, and self-criticism may predict whether non-clinical participants benefit from improved mood following either form of brief MM. The study’s findings are discussed in addition to identifying limitations, clinical implications and directions for future research.