Aprobado el proyecto de I+D+i: MSC-HEALTH

Justification and contribution of the proposal in the context of scientific/technical knowledge

In the last decade, scientific evidence has supported the relationship between the practice of mindfulness-based interventions (MBIs), psychological variables and different biomarkers of stress and cellular aging (e.g., Blackburn & Epel, 2017). These findings have promoted a significant increase in research focused on prevention and intervention in health problems. The MBIs aim at cultivating a mindful disposition in our daily lives. Mindfulness is defined as a process and a state of "awareness that emerges when we intentionally pay attention to the present moment, without judging or evaluating that experience moment to moment" (Kabat-Zinn, 1990). There are several standardized training programs, and one of the most empirically supported is Mindfulness Based Stress Reduction (MBSR) by Kabat-Zinn (2003). In the context of MBIs, programs focused on self-compassion have also been developed, which train additional skills. Self-compassion trainings aim to develop not only an attitude of mindfulness towards our own emotional experiences (i.e. an attitude of open acceptance of them), but also to develop a benevolent attitude of continuous non-self-criticism towards ourselves, as well as an attitude of openness to suffering, as a consubstantial part of life that is common to all human beings. One of such training is the Mindfulness Self-Compassion (MSC) program developed by Germer & Neff (2013ab, 2019) and Neff & Germer (2013, 2018). Previous research has found that MBIs can enhance mental health (e.g. anxiety, depression) and psychological wellbeing. MBIs have been also found to reduce the impact of chronic stress on markers of cellular aging (such as telomere length) through hormonal and inflammatory processes related to health (Epel & Praher, 2018). For example, in adults, concentration of hs-CRP inflammation marker predicts cardiovascular events. However, this field of research faces two major challenges: a) gaining a better understanding of the beneficial effects of regular long-term practice of MBIs (most studies just evaluate the efficacy of 8- week trainings, with few follow-up studies); and b) identifying the psychobiological mechanisms underlying the observed changes (Ferrari et al., 2019; Neff, 2019). Below we briefly describe the most relevant findings on the relationship between chronic stress, mindfulness, self-compassion, biomarkers of health and wellbeing

Chronic stress, biomarkers and psychopathology. Chronic stress exposure has been associated with increased systemic inflammation (e.g., interleukin-6 and C-Reactive Protein), increased insulin resistance, poor mitochondrial health, and dysregulation of basal states and functioning of the autonomic and neuroendocrine nervous system (McEwen, 2007; Wolkowitz et al, 2011). Findings from meta-analyses with clinical samples have supported the relationship between anxiety disorders, depression, stress and telomere shortening (e.g. Darrow et al, 2016; Mathur et al, 2016).

Mindfulness training and positive effects on biomarkers. Results of meta-analyses indicate that mindfulness training increases telomerase activity in peripheral blood cells (Schutte & Malouff, 2016). Alda et al, (2016) found that telomeres are significantly longer among expert meditators compared to controls. Pace et al, (2013) found that compassion-based training had positive effects on C-reactive protein and interleukin-6. The meta-analysis by Black & Slavich (2016) found that mindfulness programs produced improvement in inflammatory markers (transcription factor NF-kB; ultrasensitive C-Reactive Protein or hs-CRP), cellular immunity (CD4+ T cells in people with HIV) and in decreasing cellular aging (telomerase). Similar recent results have been obtained in our cultural context (EUDAIMON project by Feliu-Soler et al, 2016). Andrés-Rodríguez et al. (2019) found that the MBSR program has clinical efficacy in patients with fibromyalgia and also produces significant changes in immune activity (IL-10 and IL-6) with 12-month follow-up. The results of the exploratory study by Mendioroz et al. (2020) involving 17 mindfulness meditators with more than 10 years of practice suggest that long-term meditation may be related to age-associated telomere erosion. The authors indicated that although the underlying mechanisms are not yet well understood, changes in DNA methylation emerge as a factor that could contribute to this effect, although experimental studies are needed to reinforce these results. A recent meta-analysis by Sanada et al. (2020) reviewed 10 studies on the effects of MBIs (mainly MBSR and Mindfulness-Based Cognitive Therapy-MBCT by Segal et al., 2002) on biomarkers of inflammatory activity in psychiatric patients. They concluded that there is evidence that MBIs are associated with the improvement of various markers of low-grade inflammation in different pathologies, although with small effect sizes, which makes it necessary to propose new studies. These studies have been carried out in psychiatric and/or chronically ill populations. However, in the general population IL-6 may not be sensitive enough to detect changes due to regular MBIs and its interpretation is controversial, as it has been shown that its activity can be both inflammatory and anti-inflammatory (Raison et al, 2018). For this reason, following Black & Slavich (2016), we will evaluate hs-CRP.

MBIs and psychological benefits. A growing body of evidence shows that the Mindful SelfCompassion training (MSC) is associated with improvements in wellbeing (Neff & Germer, 2017; Yela et al, 2020a; Yela et al, 2021) and reductions in psychopathological symptoms (Friis et al, 2016; Jimenez et al, 2021). A recent meta-analysis found that self-compassion trainings improved the levels of mindfulness and self-compassion skills, and reduced stress, self-criticism, anxiety and depressive symptoms (Ferrari et al, 2019). Similarly, MBSR and MBCT trainings have shown efficacy in the treatment of various mental disorders (Australian Psychological Society, 2018), as well as improving health in non-clinical populations (McClintock et al, 2019; Jimenez et al, 2021). There is scientific evidence showing that MBIs programs and compassion cultivation training can reduce the stress perceived by professionals and improve the level of mindfulness and emotional regulation (Aranda et al, 2018; Burton et al, 2017). For example, Cultivation Compassion Training (CCT by Jinpa, 2010) proved significant improvements in scores of self-compassion, mindfulness, and interpersonal conflict in healthcare professionals (Scarlet et al, 2017). Brito et al. (2018) found that both MBSR and CCT improved well-being, although the latter program increased compassion skills more. Sansó et al. (2019) also comparing these two programs, concluded that the interventions are adequate to improve the aforementioned variables, with higher efficacy of the MBSR for health care professionals.

Mechanisms involved in changes in psychological variables and biomarkers. Research on the mechanisms (i.e. mediating variables) of the MSC training on wellbeing and on biomarkers is very scarce. Authors such as Epel & Prather (2018) proposed that chronic stress may be associated, through mediation of inflammatory and hormonal activity and psychological variables, with telomere deterioration and disease onset. It has been suggested that MBIs could contribute to reduce cognitions associated with stress and arousal and activate positive emotional states that would contribute to telomere maintenance (Epel et al, 2009). Montero-Marín et al (2019) observed significant improvements in fibromyalgia patients who underwent a self-compassion training through the mediation of decreased C-reactive protein compared to relaxation training. Similarly, self-compassion has been proposed to serve as a protective factor against stress-induced inflammation (IL-6) and to be associated with lower salivary alpha-amylase salivary hormone concentration (Breines et al, 2015). A variety of mechanisms have been suggested to account for the effects of mindfulness on mental health, such as decentering, value clarification, exposure, psychological flexibility, self-management skills (Brown et al, 2015), attention monitoring, acceptance of internal experiences (Lindsay & Creswell, 2017), and the development of self-compassionate attitudes (Gu et al, 2015). To date, the results obtained by our research team point out that self-compassion, perceived meaning in life, and behavioral activation explained the relationship between mindfulness and mental health. Furthermore, these results revealed that self-compassion improved mental health and subjective happiness through a greater clarification of life purposes and a decrease in experiential avoidance (Crego et al., 2020; Crego et al., 2021; Yela et al., 2020a; Yela et al., 2020b). Recently, Yela et al. (2021) have found that the decreases in experiential avoidance explained the changes in anxiety, depression and wellbeing following a MSC training in a community-based sample.