MINDFULNESS—SPECIFIC OR GENERIC MECHANISMS OF ACTION

Abstract

Mindfulness training has become an integral part of treatment approaches for a variety of behavioral and emotional problems. Brewer and colleagues 1 identify rumination and stress coping as potential common etiological components in major depression and substance abuse disorders and then speculate upon how mindfulness coping, specifically attention and acceptance, address these components and may be related to neurological realms of brain activation and mechanisms. Their efforts to integrate both behavioral phenomenology and brain mechanisms are wonderfully thought-provoking. Identifying behavioral and neurological mechanisms of action in mindfulness practices and linking them to critical dimensions of problematic functioning is essential for developing intervention science. Although I applaud the effort, I am concerned about some assumptions and approaches. Specification of both behavioral and neurological dimensions seems premature. Identifying phenotypical behavioral components shared across disorders would be helpful. However, characterizing communalities should begin at a more macro level. A premature focus on very specific behavioral experiences and responses and then linking them to specific neurological mechanisms can be misleading, and feed our propensity to seek specific behavior-linked neurological mechanisms for what are essentially more generic self-regulatory operations 2. For example, isolating rumination and stress vulnerability as core common elements of depression and substance abuse seems limiting. Affect regulation, which is a complicated, multi-component behavioral and neurological activity, seems to be at the heart of these two disorders and also integral to other disorders where mindfulness has been found to be helpful, such as anxiety and pain. Moreover, distress, often characterized as the 'fever' of mental health, is central to their notion of stress vulnerability and represents a more generic mechanism operative across most diagnostic disorders. Distress includes common elements of appraisal, coping and affect regulation. Stress vulnerability and rumination should be viewed in the larger context of affect regulation. Premature focus is especially important when trying to link behavioral coping activities to specific change mechanisms. The authors identify attention and acceptance as central mechanisms of mindfulness practices. Can these mechanisms be isolated and are they unique active ingredients of mindfulness practices? In this vein it would also be important to know how mindfulness is related to similar phenomenon such as Benson's relaxation response, transcendental meditation, relaxation imagery and muscle relaxation techniques. Many of these activities have also demonstrated brain and cardiovascular effects but use very different techniques, such as focusing upon a specific mantra and the distraction of relaxing imagery. One study found no significant differences in stress responding between groups using mindfulness and somatic relaxation 3. There may be a common pathway for all of these effects that is not unique to mindfulness. Recent studies on mindfulness practices and pain indicate that cortical thickening in affective, pain-related brain regions lowers pain sensitivity for those experienced in Zen meditation. It is not clear whether this effect is related to heightened control, awareness or acceptance of an emotional state 4. Thus, it is not clear whether attention, control or distraction is the active ingredient, as meditation influences different subsystems of attention 5 and involves both activation and deactivation 6. Thus it would be important to establish whether mindfulness activities represent a more generic affect regulation skill or a specific change process. Meditation practices from a number of different traditions have demonstrated both acute and long-term effects on physiological functioning and general wellbeing 7, 8. Are these multiple paths to a similar mechanism, or is mindfulness a unique type of intervention separable from other types of relaxation as is often claimed 4? I would also like to add several additional cautions. In this important work of understanding connections among biological and behavioral phenomena, we should avoid physiological and biological reductionism and the misguided view that behavioral phenomena are more 'real' if we can find specific areas of brain structure, activation or biochemistry that are associated uniquely with the behaviors. Brain and behavior are interactive and complexly interrelated, often eluding our efforts of isolation and our linear, dichotomous thinking about brain–behavior phenomena. It is also important to differentiate between brain activation, neurotransmitter effects, functional areas of the brain and brain structure and morphology. The actions of many medications with ingredients targeting specific areas of brain functioning are often shown to have multiple interactive neurobiological effects. Behavioral correlates should be even more elusive. Clearly, the authors have been successful in stimulating questions and deepening our ways of thinking about mindfulness. However, it remains to be seen how to best characterize mindfulness effects both at a behavioral and a neurobiological level. Do mindfulness strategies and practices act as a generic pain reliever and self-control mechanism, or do the elements of attention and acceptance operate as targeted, specific behavioral practices to influence well-specified brain structures in a defined manner? We need many more studies examining cross-disorder consistencies as well as dismantling studies to isolate active ingredients of mindfulness practice in order to ultimately able to connect behaviors and brain. None.