The Effects of Mindfulness-Based Cognitive Therapy on Affective Memory Recall Dynamics in Depression: A Mechanistic Model of Rumination

Abstract

Objectives: converging research suggests that mindfulness training exerts its therapeutic effects on depression by reducing rumination. Theoretically, rumination is a multifaceted construct that aggregates multiple neurocognitive aspects of depression, including poor executive control, negative and overgeneral memory bias, and persistence or stickiness of negative mind states. Current measures of rumination, most-often self-reports, do not capture these different aspects of ruminative tendencies, and therefore are limited in providing detailed information about the mechanisms of mindfulness. Methods: we developed new insight into the potential mechanisms of rumination, based on three model-based metrics of free recall dynamics. These three measures reflect the patterns of memory retrieval of valenced information: the probability of first recall (Pstart) which represents initial affective bias, the probability of staying with the same valence category rather than switching, which indicates strength of positive or negative association networks (Pstay), and probability of stopping (Pstop) or ending recall within a given valence, which indicates persistence or stickiness of a mind state. We investigated the effects of Mindfulness-Based Cognitive Therapy (MBCT; N = 29) vs. wait-list control (N = 23) on these recall dynamics in a randomized controlled trial in individuals with recurrent depression. Participants completed a standard laboratory stressor, the Trier Social Stress Test, to induce negative mood and activate ruminative tendencies. Following that, participants completed a free recall task consisting of three word lists. This assessment was conducted both before and after treatment or wait-list. Results: while MBCT participant’s Pstart remained relatively stable, controls showed multiple indications of depression-related deterioration toward more negative and less positive bias. Following the intervention, MBCT participants decreased in their tendency to sustain trains of negative words and increased their tendency to sustain trains of positive words. Conversely, controls showed the opposite tendency: controls stayed in trains of negative words for longer, and stayed in trains of positive words for less time relative to pre-intervention scores. MBCT participants tended to stop recall less often with negative words, which indicates less persistence or stickiness of negatively valenced mental context. Conclusion: MBCT participants showed a decrease in patterns that may perpetuate rumination on all three types of recall dynamics (Pstart, Pstay, and Pstop), compared to controls. MBCT may weaken the strength of self-perpetuating negative associations networks that are responsible for the persistent and “sticky” negative mind states observed in depression, and increase the positive associations that are lacking in depression. This study also offers a novel, objective method of measuring several indices of ruminative tendencies indicative of the underlying mechanisms of rumination.

Mindfulness-Based Interventions in Psychiatry

“…Research has largely supported this notion, and shown that these processes are central components and active ingredients of MBCT. Following MBCT training, participants exhibit improved self-reported mindfulness (43–50), reduced rumination (43, 45–48, 51–53) and worry (43, 47, 53), improved meta-awareness (52, 54, 55), increased self-compassion (56, 57), and reduced emotional reactivity (58). Moreover, these improvements at least partially mediated or predicted the effect of MBCT on treatment outcome (see 59–61 for reviews), with the strongest effects found for mindfulness, rumination, worry, and emotional reactivity.…”

Mental and Physical (MAP) Training: A neurogenesis-inspired intervention that enhances health in humans

“…We propose that the combination of the two activities is better than either one alone, again based on evidence that new neurons are kept alive by learning once they are produced. For the intervention, we chose activities that humans can readily engage in and yet are known to enhance mental and physical health (Herring et al, 2012; Heyward, 1998; Hofmann et al, 2010; Kabat-Zinn, 1990; Davidson and McEwen, 2012; Chiesa and Serretti, 2010; van Vugt et al, 2012). Our goal was to translate the neurogenesis/ learning data into a clinical intervention that can be easily disseminated and practiced by everyone in our community.…”

Mindfulness-Based Cognitive Therapy in Major depressive disorder - systematic review and metanalysis

“…The scores of the Pedro scale that measures the quality of the trials ranged from 5 to 10 points (total mean of all studies = 7.1 SD = 1.8). The nonrandomized studies presented a Pedro score of 5 points (32,33,37), the randomized studies with two groups from 5 to 10 points (2,13,34,35,39,41) and those with three groups from 6 to 9 points (36,38,40).…”

“…Firstly, the reduction of rumination and negative thoughts and the increase in sustaining trains of positive words were shown in two studies, with the effect in both the MBCT and the Control groups (2,33). Both associated results are important in the treatment of MDD, as rumination is a persistent symptom and, although the content of rumination is typically negative, it is the persistent style (not content) of thought which is the central key to rumination, causing the person to have difficulties in attention and cognition (44,45).…”

“…Major depressive disorder (MDD) is a complex disease with patterns of persistence, remission and relapse, which presents a likelihood of recurrence greater than 80% (1,2). It has a global prevalence of 16% and it is estimated that it will be the second most prevalent illness by 2020, with an increase of 6.2% by 2030 (3,4).…”