Brief mindfulness-based training and mindfulness trait attenuate psychological stress in university students: a randomized controlled trial

Abstract

Background: Psychological distress in University settings has grown and became a public health concern. In this context, contemplative practices such as mindfulness have been proposed as a strategy to help students on stress management.

Methods: Forty university students (20 female), aged between 18 to 30 years (mean = 24.15; SD = 3.56), with no previous experience with meditation or yoga were recruited at the Federal University of Rio Grande do Norte and randomized to a mindfulness training (MT) or active control (AC) groups. We analyzed measures of anxiety, affect, stress, as well as state and trait mindfulness in order to evaluate the effects of trait mindfulness and a brief mindfulness intervention in forty healthy young students. Participants were classified as Low (n = 27, females = 13) or High (n = 13, females = 7) Trait Mindfulness by k-means clustering and compared between them using Wilcoxon sum rank test. Furthermore, the sample was randomly allocated to an AC (n = 20, females = 10) or a MT (n = 20, females = 10) group, and mixed analysis of variance was performed to analyze the effect of interventions. The mechanisms and role of trait mindfulness in the intervention was assessed by a moderated mediation analysis.

Results: We found that High Trait individuals have lower anxiety trait, anxiety state and perceived stress levels. Only the MT group reduced their anxiety state and perceived stress after the intervention and increased their state mindfulness. Both groups reduced negative affect and cortisol, and no change was found in positive affect. Moderated mediation analysis showed that the training-induced change in state mindfulness mediated the increase in positive affect and the decrease in perceived stress and cortisol, regardless of trait mindfulness. For anxiety state the decrease only occurred in individuals with High Trait Mindfulness.

Conclusions: Together, these results suggest that higher trait mindfulness is associated with low levels of psychological distress and that a brief mindfulness-based intervention seems to be useful to reduce distress measures in university students.

Trial registration: ReBEC, U1111-1194-8661. Registered 28 March 2017-Retrospectively registered, http://www.ensaiosclinicos.gov.br/rg/RBR-7b8yh8.

Keywords: Cortisol; Mindfulness training; Psychological distress; Psychological well-being; Trait mindfulness.

Fig. 1

Experimental design (a) and CONSORT (Consolidated Standards of Reporting Trials) study flow (b). Forty-three participants were allocated (Control: n = 23, Mindfulness: n = 20) but 3 excluded from Control, remaining 20 individuals per group. MBI = Mindfulness-Based Intervention

Fig. 2

Cluster plot showing the two dimensions with higher variability (a) and centers of grouping variables for each cluster (b), showing a clear separation between individuals with low (Cluster 1) from those with high mindfulness trait (Cluster 2). (c) Boxplots of FFMQ facets. Wilcoxon sum rank test showed that all facets are significantly different between clusters. *p ≤ .05, **p ≤ .01, ***p ≤ .001

Fig. 3

Well-being measures before intervention between low and high mindfulness trait. For means and standard deviations, see Table 1. Wilcoxon sum rank test, #p < .10, *p < .05, **p < .01

Fig. 4

Facets of FFMQ before and after interventions for each group. For means and standard deviations, see Table 2. Mixed ANOVA test, #p ≤ .10, *p ≤ .05, **p ≤ .01, ***p ≤ .001

Fig. 5

Well-being measures before and after interventions for each group. Mindfulness training induced an overall change in psychological and physiological variables. For means and standard deviations, see Table 2. Mixed ANOVA test, #p ≤ .10, *p ≤ .05, **p ≤ .01, ***p ≤ .001

Fig. 6

Conceptual diagram of second-stage moderated mediation showing overall mediation effect of mindfulness training and the role of high mindfulness trait as moderator of mediation effect of State Mindfulness on Anxiety State. Values on State Mindfulness → Outcomes pathways indicate b₁ estimate, while that on Mindfulness Trait → Anxiety State indicate b ₃ estimate and Index of Moderated Mediation for High Mindfulness Trait condition (ω_High). Black arrow stands for significant path and grey line stands for no significant path. For ease of presentation c’-path is omitted, see Table 3 for indexes of moderated mediation, bootstrapped confidence interval and c’-path. *p ≤ .05, **p ≤ .01