Non-replication of structural brain changes from Mindfulness-Based Stress Reduction: Two combined randomized controlled trials

Abstract

Studies purporting to show changes in brain structure following the popular, eight-week Mindfulness-Based Stress Reduction (MBSR) course are widely referenced despite major methodological limitations. Here, we present findings from a large, combined dataset of two, three-arm randomized controlled trials with active and waitlist (WL) control groups. Meditation-naive participants (n=218) completed structural MRI scans during two visits: baseline and post-intervention period. After baseline, participants were randomly assigned to WL (n=70), an 8-week MBSR program (n=75), or a validated, matched active control (n=73). We assessed changes in gray matter volume, gray matter density, and cortical thickness. In the largest and most rigorously controlled study to date, we failed to replicate prior findings and found no evidence that MBSR produced neuroplastic changes compared to either control group, at either the whole-brain level or in regions of interest drawn from prior MBSR studies.

No Effects of a Brief Mindfulness Intervention on Controlled Motivation and Amotivation, but Effect Moderation Through Trait Mindfulness: a Randomized Controlled Trial

“…Note. Introjected motivation is featured in this figure, but was not differentiated empirically from identified motivation in the present study reduction) has found that a minimum of 27 h of practice time is needed for a change in amygdala volume (Kral et al, 2022). These findings indicate larger neuronal changes for longer mindfulness interventions compared to only brief mindfulness interventions.…”

“…There is some evidence that even brief mindfulness interventions are sufficient to achieve a state of mindfulness that affects brain activity as well as cognition and feelings (Medvedev et al, 2017 ). On the other hand, recent research on MBSR (mindfulness-based stress reduction) has found that a minimum of 27 h of practice time is needed for a change in amygdala volume (Kral et al, 2022 ). These findings indicate larger neuronal changes for longer mindfulness interventions compared to only brief mindfulness interventions.…”

Research in Mindfulness Interventions for Patients With Fibromyalgia: A Critical Review

“…The inclusion of active controls is important in what concerns study design namely because it helps to solve the question of double-blinding ( Davidson and Kaszniak, 2015 ). A recent study analyzed the effects of including a validated well-matched active control group with a large sample size and defined in a randomized manner in the effects of MBSR in brain structure ( Kral et al, 2022 ). This study failed to confirm previous results showing neuroplastic changes induced by MBSR groups in comparison to active controls, which reinforces the importance of defining the best control groups for each MBI intervention which may probably require both active and waiting list groups ( Kral et al, 2022 ).…”

“…A recent study analyzed the effects of including a validated well-matched active control group with a large sample size and defined in a randomized manner in the effects of MBSR in brain structure ( Kral et al, 2022 ). This study failed to confirm previous results showing neuroplastic changes induced by MBSR groups in comparison to active controls, which reinforces the importance of defining the best control groups for each MBI intervention which may probably require both active and waiting list groups ( Kral et al, 2022 ). As to fibromyalgia, it was never evaluated the importance of defining control groups in MBI research.…”

The impact of mindfulness meditation on social and moral behavior: Does mindfulness enhance other-oriented motivation or decrease monetary reward salience?

“…Neuroimaging evidence shows that MM might induce neuroplastic changes in the structure and the function of brain regions involved in attentional processes, memory, emotion regulation, self-awareness, exteroceptive and interoceptive body awareness, and self-control (Fox et al, 2014;Tang et al, 2015; but see Kral et al, 2022 for a different view). Other meditation practices include loving-kindness meditation (LKM, aimed at developing positive emotions toward oneself and others) and compassion meditation (CM, aimed at cultivating compassion toward others) (Hofmann et al, 2011).…”