Abstract
Objective: Mindfulness-based interventions (MBIs) such as mindfulness-based stress reduction (MBSR) and mindfulness-based cognitive therapy (MBCT) have been shown to be effective for reducing worry and rumination. Recently, brief MBIs have also been found to be beneficial for psychological wellbeing, and this includes some preliminary evidence for the use of brief, self-help MBIs delivered online. The current study aimed to assess the effect of a brief, online self-help MBI on worry and rumination, and assess the extent to which this effect was specific to MBIs. Methods: A randomised controlled trial was conducted with 172 participants in a self-selected sample. Recruitment took place at a University campus and online via social networking websites. Participants were randomised to one of three groups (MBI, guided visual imagery (GVI) or wait-list control). Self-report measures of mindfulness, worry and rumination were completed at three time points (pre, post and one-week follow-up). Mediation analyses were performed using bootstrapping sampling procedures. Results and conclusions: Both MBI and GVI groups brought about significant improvements in mindfulness skills, worry and rumination when compared to a wait-list control, and improvements in worry and rumination were mediated by mindfulness skills. There were no significant differences between the MBI and GVI groups on improvements in mindfulness, worry or rumination, although this may have been due to low power. Improvements in mindfulness skills consistently predicted reductions in rumination and worry. The lack of significant difference between MBI and GVI might be explained by a lack of power, expectancy effects, or unforeseen overlaps in mechanisms between GVI and mindfulness.