Thursday, August 19, 2010
The Effectiveness of an Acceptance and Commitment Therapy Self-Help Intervention for Chronic Pain
Monday, August 16, 2010
Functional Neural Correlates of Mindfulness Meditations in Comparison with Psychotherapy, Pharmacotherapy, and Placebo Effect
I found the placebo piece of the review particularly interesting as there’s a huge research literature showing placebo effects are powerful enough to be a treatment in themselves. Like psychotherapy, it’s hard to create an adequate placebo substitute for something like meditation, especially as people know more about it today than they did decades ago when this research began.
The authors’ findings suggest that mindfulness meditation may help facilitate a greater flexibility in emotion regulation, and an improved ability to step back from negative mood states by engaging the frontal cortex (higher order functions) in order to dampen amygdala activation (emotion response, especially fear). The authors also found there’s a great deal of overlap in the brain structures activated by mindfulness meditation, psychotherapy, pharmacotherapy, and placebo effects.
They make a preliminary suggestion that mindfulness meditation, psychotherapy, and placebo act through “top down” regulation (i.e., through other processes), whereas antidepressants have a “bottom-up” effect (i.e., more directly). For example, they suggest mindfulness meditation may regulate the amygdala through frontal brain areas whereas antidepressants target the amygdala directly. I found this curious, as Irving Kirsch and others have recently suggested that much of the benefit from antidepressants is through placebo or expectancy effects (here's a short review of this debate). I am not trained as a neuroscientist nor am I an expert in this area of research, so I won’t directly challenge the authors’ conclusions. Nonetheless, I was left uncertain how much of the notion of grouping meditation, psychotherapy, and placebos into one category, and antidepressants in another, is based more on theory than on data.
Nonetheless, I think the authors did a nice job of trying to organize and summarize a growing but somewhat disparate body of research. Additionally, they’ve raised some important questions for other researchers to begin to explore in a more systematic manner. As I blogged about last week, Fletcher and colleagues (2010) recently suggested ways in which a neuroscientific understanding of mindfulness may be refined. This is a really exciting avenue of study, but I agree with the latter authors in that what researchers should really focus on is building our understanding of the neurological underpinnings of mindfulness and meditation in a very deliberate and step-by-step approach.
Full Citation:
Chiesa, A., Brambilla, P., & Serretti, A. (2010). Functional neural correlates of mindfulness meditations in comparison with psychotherapy, pharmacotherapy and placebo effect. Is there a link? Acta Neuropsychiatrica, 22(3), 104-117.
Monday, August 9, 2010
Searching for Mindfulness in the Brain
In the new journal Mindfulness, Fletcher, Schoendorff, and Hayes, researchers well known within the Acceptance and Commitment Therapy (ACT) community, published an article about refining the approach towards using neuro-imaging techniques (i.e., brain scans) to study mindfulness.
The authors point out some of the flaws in the current literature, such as the lack of precision about definitions of mindfulness and accompanying processes, and difficulty measuring subjective reports of different psychological states. The authors advocate greater precision in understanding and delineating the different processes that may underlie mindfulness before subjecting mindfulness to neurobiological study.
As they authors admit, the lens through which they seek to understand mindfulness is the behaviorist approach ACT. They readily acknowledge that this is but one way to understand mindfulness. Their main point is that some clearly defined model of mindfulness, whatever that may be, is necessary before a true neurological study of mindfulness can be undertaken. Otherwise, inquiry may lead to sloppy science.
I applaud the authors for this undertaking. Although I think there is a great deal of value in neuroscience, there is such a mystique surrounding it (e.g., “It’s the brain, so it must be true!”), that I think some of the methodological limitations get overlooked. For example, as with any research technique, there is random error in measurement. The authors note an amusing study by Bennett and colleagues (2009) that found the brain area of dead salmon reliably lit up when the fish were shown emotional scenes. It’s highly unlikely the dead fish were having an emotional reaction! Yet this is precisely the problem we face when we stick people in a scanner and ask them to meditate without first clearly defining the task (e.g., What does it mean to meditate?), and what we’re looking for.
Although it’s not my main area of training, I find the neuroscience research on mindfulness and meditation pretty interesting. I think there is a great deal of potential in this particular avenue of exploration. However, I agree wholeheartedly with Fletcher and colleagues that there should be a movement towards greater scientific rigor with studies executed in a more systematic fashion.
For Full Citation:
Fletcher, L. B., Schoendorff, B., & Hayes, S. C. (2010). Searching for Mindfulness in the Brain: A Process-Oriented Approach to Examining the Neural Correlates of Mindfulness. Mindfulness, 1(1), 41-63.
Monday, August 2, 2010
The Effects of Brief Mindfulness Meditation Training on Experimentally Induced Pain
Before and after the intervention, participants were tested on pain threshold using painful electrical stimulation. The experimenters obtained ratings of a “low” threshold (rated a 2 and 3 on a 0-6 scale) and a “high” threshold (rated 4 and 5).
In Experiment 1, participants received a mindfulness meditation intervention after pain threshold was assessed. The mindfulness meditation intervention was specifically designed to be very brief. After the first testing session, participants engaged in 20 minute mindfulness meditation trainings for 3 consecutive days, with different skills taught each day with increasing detail. They were then retested on pain threshold.
In Experiment 2, participants completed three conditions: 1.) baseline; 2.) “math distraction task” (participants were asked to subtract from 1000 by 7); 3.) or a relaxation task. The order of administration was counter-balanced to account for order effects. Similar to the Experiment 1, a second pain testing session was conducted three days after the first.
In Experiment 3, participants completed relaxation, math distraction, and mindfulness meditation conditions. The order of administration was counter-balanced to account for order effects.
Across three experiments, participants in the mindfulness meditation intervention exhibited decreases in subjective pain ratings and state anxiety, and increases in mindfulness. Additionally, participants in the mindfulness meditation intervention reported less pain at both the high and low intensities compared to their baseline scores before the intervention. There was also pain reduction for participants using the math distraction task but not the relaxation task.
The authors conclude that mindfulness meditation can dampen pain response—an analgesic effect—even after only a brief intervention.
There are some weaknesses to this study. Samples sizes across each experiment ranged from 20-22, which are a little small, especially as conditions were counterbalanced within each experiment. Additionally, these were healthy college students: people with chronic pain conditions were screened out.
Nonetheless, the study offers some indication that mindfulness meditation has a greater analgesic effect than relaxation and distraction, and that this effect can be accessed with a very brief intervention.
For the full study, click here.
Full citation:
Zeidan, F., Gordon, N. S., Merchant, J., & Goolkasian, P. (2010). The Effects of Brief Mindfulness Meditation Training on Experimentally Induced Pain. The Journal of Pain, 11(3),199-209.