Processus psychologiques de réduction de l’anxiété dans le MBSR : décentration et pleine conscience

La décentration réduirait l’anxiété physiologique. Conscience et non-réactivité diminueraient l’inquiétude.

Des chercheurs sont arrivés à cette conclusion en examinant les mécanismes psychologiques qui expliquent une diminution de l’anxiété physiologique et de l’inquiétude dans le trouble d’anxiété généralisée (TAG) en comparant deux groupes au format similaire : un groupe MBSR (avec une intervention allégée presque de moitié) de 19 personnes et un groupe de 19 personnes recevant une formation à la gestion du stress (SME) sur la nutrition et la diététique, l’exercice physique, le sommeil, la gestion du temps, la résilience et un exercice de balle de stabilité, mais sans méditation ou intervention corps-mental.

Selon un article (en anglais) de 2015 : de Hoge, E.A., Bui, E., Goetter, E. et al. publié dans Cognitive Therapy and Research April 2015, Volume 39, Issue 2, pp 228–235.

Change in Decentering Mediates Improvement in Anxiety in MBSR for Generalized Anxiety Disorder

voir le résumé en anglais : Change in Decentering Mediates Improvement in Anxiety in Mindfulness-B

Extraits :

Mindfulness training, adapted from Buddhist meditation practices, teaches participants to increase awareness of present-moment experiences, including thoughts, emotions, and physical sensations, with a gentle and accepting attitude (Bishop et al. 2004). (…)

Results from both controlled and uncontrolled studies have demonstrated the efficacy of mindfulness-based interventions for stress and anxiety in a variety of patient populations (e.g., Hofmann et al. 2010).

More recently, researchers have begun to examine the mechanisms, or therapeutic processes, by which these interventions exert their beneficial health effects.

Hypothèses : One candidate mechanism, or process, is dispositional mindfulness (i.e., the tendency to be aware of one’s present moment experiences with a non-judgmental attitude; Bishop et al. 2004). (…) Another putative therapeutic mechanism in mindfulness-based treatments is decentering.

Qu’est-ce que la décentration (decentering), la distanciation ou la défusion cognitive (terme relié plus spécifique aux pensées) ?

Decentering is a metacognitive capacity of individuals to observe items that arise in the mind (e.g., thoughts, feelings, memories, etc.) as mere psychological events (Fresco et al. 2007a, b; Teasdale et al. 2002).

Decentering promotes disengagement from internal experiences (i.e., an intense emotion, its corresponding motivational impetus, and associated maladaptive self-referential processing) in favor of adopting a more distanced perspective.

This ability also involves recognizing that one’s thoughts, feelings, and urges are transient internal events rather than inherent, permanent aspects of the self or accurate representations of reality (Fresco et al. 2007a; Segal et al. 2002).

Some have noted that decentering and mindfulness are theoretically similar constructs (Carmody et al. 2009); however, mindfulness involves bringing enhanced awareness coupled with an attitude of nonjudgment, whereas decentering more specifically refers to the ability to adopt a psychologically
distanced stance.

Studies report psychological benefits from promoting distance from the self in time (e.g., viewing inner experiences as temporary; Watkins et al. 2000) and distance from the self in space (e.g., viewing inner experiences as physical objects that are separate from oneself; Kalisch et al. 2005).

Son utilité dans la dépression

A series of studies utilizing a self-report measure of decentering (Fresco et al. 2007a) reveal that, as compared to healthy control participants, patients with major depressive disorder evidence lower levels of decentering (Fresco et al. 2007a) and demonstrate gains in decentering following treatment with cognitive behavioral therapy (CBT) but not antidepressant medication (ADM) (Fresco et al. 2007b). Further, gains in decentering during acute treatment with CBT (Fresco et al. 2007b) or prophylactic treatment with mindfulness-based cognitive therapy (MBCT) (Bieling et al. 2012) are predictive of a more durable treatment response.

Method

Les deux formations comparées :

  • The MBSR course was modified for this clinical population with the shortening of the ‘‘retreat’’ day to 4 h, and the shortening of home exercises from 40 to 20 min (for details, see Hoge et al. 2013).
  • The SME (stress management education) was designed as an active control intervention for MBSR to control for the non-specific effects of treatment, such as group support, attention from the instructor, and participants’ expectations. The course focuses on improving overall health and wellness through education about diet, exercise, sleep, time management, and resilience, but it does not contain any meditation or other mind–body intervention. SME also included a ‘half-day of stress reduction’ with additional components, such as a stability ball exercise class and a dietician’s lecture.

Questionnaires utilisés ;

  • Structured Clinical Interview for the DSM-IV (SCID). Groups were determined by the Structured Clinical Interview for the DSM-IV (SCID) (First et al. 2002), were randomized to either a slightly modified mindfulness-based stress reduction (MBSR) or stress management education (SME).
  • Mindfulness The 39-item Five Facet Mindfulness Questionnaire (FFMQ; Baer et al. 2006) was used to assess
    change in mindfulness. (…) Prior factor analyses have yielded five facets of mindfulness:

    • observing (attending to or noticing internal and external stimuli such as sensations, emotions, cognitions, sights, sounds, and smells);
    • describing (mentally labeling these stimuli with words);
    • acting with awareness (attending to one’s current actions, as opposed to behaving automatically or absent-mindedly);
    • non-judging of inner experience (refraining from evaluation of one’s sensations, cognitions, and emotions); and
    • non-reactivity to inner experience (allowing thoughts and feelings to come and go, without getting caught in them or reacting to them). (…)
  • Decentering was assessed using the 11-item decentering subscale of the Experiences Questionnaire (also called ‘‘Experiences Questionnaire, Wider Experiences’’) (Fresco et al. 2007a). (…)

We chose self-reported anxiety symptoms and worry as the primary outcomes at baseline and week 8 (endpoint):

  • The 21-item self-report Beck Anxiety Inventory (BAI; Beck et al. 1988)
  • The 15-item self-report Penn State Worry Questionnaire- Past Week (PSWQ-PW; Stober and Bittencourt 1998) was used to assess worry

Preliminary correlation analyses found that change in GAD symptom severity was strongly and inversely associated with change in mindfulness (r = -0.54, p\0.001) and change in decentering (r = -0.53, p\0.001). Change in mindfulness and in decentering were also correlated (r = 0.56, p\0.001).

Discussion

In this sample of patients with GAD who were trained in MBSR or received an attention control, we found evidence that changes in both decentering and mindfulness may mediate the effect of MBSR on symptoms of GAD.

In particular, results from our study suggest that MBSR promotes reductions in anxiety (i.e., BAI score) through increases in decentering, but reduces worry (i.e., PSWQ score) through increases in mindfulness, specifically via increases in awareness and nonreactivity.

These results lead us to draw three important conclusions. First, these results provide evidence that mindfulness and decentering are indeed distinct constructs. Second, MBSR promotes reductions in GAD symptoms through different mechanisms, namely mindfulness and decentering, suggesting that both skills are crucial components of successful GAD treatment. Finally, decentering and mindfulness appear to differentially influence symptoms of GAD.

Specifically,

  1. decentering appears to be a process by which MBSR reduces anxiety, especially physiological anxiety (which is the primary construct measured by BAI), while
  2. mindfulness (awareness and nonreactivity) appears to be a key process by which MBSR reduces worry.

Concerning the role of decentering in mediating outcomes in MBSR, these findings extend previous findings suggesting that decentering predicts improvements (or lack of relapse) in psychological symptoms after MBSR and MBCT (Bieling et al. 2012; Carmody et al. 2009). It could be that having a psychologically distanced stance buffers individuals from the distress associated with physical signs of anxiety. Although they were not examining individuals with anxiety conditions per se, a recent study found that decentering was beneficial among individuals with chronic pain (McCracken et al. 2013). Taken together, these findings suggest that decentering may be a crucial process by which psychotherapies target and alleviate distressing physical sensations. Decentering in response to anxiety may make one less prone to the detrimental consequences that can result from focusing attention on anxiety symptoms, which has been known to exacerbate negative affect (Mor and Winquist 2002).

The current study also found that mindfulness mediated reductions in worry. Specifically, awareness and nonreactivity, emerged as two key mechanisms by which MBSR reduces worry. These findings are in concert with results of a recent study which found that nonreactivity, nonjudging, and acting with awareness, were significantly and negatively associated with worry (Fisak and von Lehe 2012). Similar to what they concluded, it could be that individuals who have a more mindful response to worries,are less likely to experience the associated emotional distress that accompanies worry. For example, by not reacting to the worries, individuals may be less likely to attempt to control or suppress the worry, which can paradoxically increase distress (Abramowitz et al. 2001). Lastly, these results provide evidence that mindfulness and decentering are indeed distinct constructs. Given these findings showing that MBSR is associated with gains in decentering and improvements in mindfulness (nonreactivity and acting with awareness), an important future direction is to develop treatments that deliberately and focally promote decentering and mindfulness for anxiety and depressive disorders characterized by lack of this type of capacity.

ACT ou la thérapie d’acceptation et d’engagement (acceptance and commitment therapy), proche du MBSR

(…) Another cognitive-behavioral psychotherapy is acceptance-based behavior therapy (ABBT), which encourages use of mindfulness exercises, teaching distancing from thoughts, and engagement in important, values-consistent activities; this treatment has demonstrated efficacy in treating GAD and in increasing decentering (Hayes-Skelton et al. 2012; Roemer et al. 2008, 2013).

Several limitations should be mentioned.

  • First, findings are limited by small sample size, so they should be interpreted with caution. (…)
  • In addition, our anxiety symptom outcome measure, the BAI, has an emphasis on physiological arousal symptoms rather than a focus on the core symptoms of GAD. Therefore, it is possible that the BAI did not capture precisely the distress associated with GAD.
  • Lastly, we studied a sample with GAD and therefore our findings are not necessarily generalizable to other conditions. Future studies could extend this research by examining these constructs in different populations. Such research would be particularly useful as contemporary paradigms seek to identify underlying dimensions of psychological functioning.

 

Mots clés reliés : le « non-attachement » comprendrait la « décentration » (ou « défusion cognitive » ou « distanciation des pensées » ou « prise de perspective » temporelle ou spatiale).