Posted 05.19.2016 | by AMRA

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Older adults who complain of subjective cognitive decline (SCD) often appear normal in day-to-day functioning and on clinical assessment, but 60% of them eventually develop either mild cognitive impairment or Alzheimer’s Disease. This makes older adults with SCD a prime target for interventions aimed at preventing or slowing cognitive decline.

Smart et al. [Journal of Alzheimer’s Disease] conducted a randomized controlled pilot study to test the effects of mindfulness training versus a psycho-educational control on measures of attention, brain structure and function, and self-reported cognitive complaints, mood, and mindfulness in adults with SCD.

A sample of 23 healthy older adults and 15 older adults with SCD (predominantly Caucasian men and women, average age = 70) were randomly assigned to either an 8-week mindfulness training based on MBSR that was tailored for older adults, or a 5-week program that provided education on memory and aging, situational factors that affect memory, and strategies to compensate for memory difficulties. Participants completed self-report measures of memory complaints, depression, and mindfulness (the Five Facet Mindfulness Questionnaire, or FFMQ).

They also completed an attentional capacity task that required them to be vigilant and respond or withhold responding to letters presented on a computer screen. An electroencephalogram (EEG) recorded the magnitude of their brain’s P3 evoked response potentials (ERPs) while performing this task. Higher P3 ERPs reflect increased attentional capacity and are known to decrease in amplitude with SCD. All these measures were obtained both before and after intervention. Structural magnetic resonance imaging (MRI) was also included to detect changes in total brain volume from pre- to post- intervention.

Adults with SCD reported a greater number of subjective memory complaints and had a lower total mindfulness score on the FFMQ than did healthy adults (partial η2=.44). SCD adults’ subjective memory complaints and memory self-efficacy improved equally in both the mindfulness and the control groups. Neither of the interventions significantly improved FFMQ scores.

The P3 amplitudes of the SCD adults in the mindfulness group improved significantly, while the amplitudes of the SCD adults in the control group did not (partial η2=.15). SCD patients increased their P3 amplitudes by an average of 28%, whereas the healthy adults showed no overall change. For SCD adults in the mindfulness group, P3 amplitudes were impaired prior to intervention, but were indistinguishable from those of the healthy adults after intervention. Mindfulness participants significantly reduced their response time variability on the computerized vigilance task, reflecting improved moment-to-moment attention, whereas control group participants showed increased variability (partial η2=.14).

Mindfulness participants’ total brain volume significantly increased, whereas control group brain volume did not (Cohen’s d=1.8). Unfortunately, not all of the participants’ MRIs were of sufficiently good quality to be included in this analysis. As a result, the researchers were unable to statistically test whether this tendency for mindfulness to increase brain volumes was more pronounced for either the SCD or the healthy adults.

This pilot study shows that mindfulness training can improve moment-to-moment regulation of attention and corresponding brain function in older adults with subjective cognitive decline. Improved attentional regulation may serve as a resource to help mitigate functional impairments resulting from early memory decline. The study also demonstrates an effect of mindfulness training on brain volume in older adults.

More research is needed to determine whether mindfulness training reduces or slows the progression to mild cognitive impairment or Alzheimer’s Disease, or reduces the disability associated with early phases of those disorders.

Reference:

Smart, C. M., Segalowitz, S. J., Mulligan, B. P., Koudys, J., & Gawryluk, J. R. (2016). Mindfulness training for older adults with subjective cognitive decline: Results from a pilot randomized controlled trial. Journal of Alzheimer’s Disease.

[Link to abstract]