Posted 08.24.2017 | by AMRA

Elderly anxiety and depression sufferers often report subjective problems with memory and cognition. They also perform more poorly on objective measures of short-term memory, verbal fluency, and the ability to ignore irrelevant cues while focusing on a task. Stress can play an important role in worsening anxiety and depression and also in degrading cognitive function.

There is evidence that cortisol, a hormone secreted during stress, can have a harmful effect on brain cells in the hippocampus, which may in turn negatively affect memory and cognition. Reducing stress may therefore yield a double benefit: reducing anxiety and depression, and improving memory and cognition.

Wetherell et al. [Journal of Clinical Psychiatry] explored whether Mindfulness-Based Stress Reduction (MBSR) could improve clinical symptoms and cognitive functioning better than a control group in elderly people suffering from anxiety and/or depression who also experience subjective cognitive difficulties.

The researchers randomly assigned 103 elderly patients (average age = 72 years; 75% Female; 83% Caucasian) with clinical diagnoses of anxiety and/or depressive disorders and with subjective cognitive complaints to either an 8-week group MBSR intervention or an 8-week Health Education control intervention. The Health Education groups met for the same frequency and duration as the MBSR groups, but focused on understanding and managing anxiety and depression, eating well, managing medications, and communicating with one’s heath care providers.

Patients were assessed at baseline, at the end of the intervention, and at 3-and-6-month follow-ups. Outcomes were assessed on measures of psychiatric symptoms, verbal memory, verbal fluency, the ability to ignore distracting cues and stay focused on a task, mindfulness (as measured by the Cognitive and Affective Mindfulness Scale-Revised), and average peak salivary cortisol.

Despite randomization, the health education controls were, on the average, two years older than the MBSR participants, had a higher burden of illness, and were twice as likely to be prescribed antidepressants.

Results showed that MBSR participants had a significantly greater improvement in their immediate verbal recall of words on a list (Cohen’s d=0.28) and information contained in stories (d=0.42) than controls. They also showed significantly greater improvements in depression (d=0.46), worry (d=0.42), and mindfulness (d=0.57).

Blinded raters rated 47% of the MBSR participants as either “much” or “very much clinically improved,” compared to 27% of the health education participants. This greater clinical improvement for MBSR patients was maintained at 3-and-6-month follow-up, when a significant improvement in anxiety also emerged for MBSR participants.

No group differences were found for either verbal fluency or the ability to ignore distracting irrelevant cues. There was no overall group difference in peak cortisol level, but a group difference emerged when only the data from participants with baseline cortisol levels above the median were analyzed. MBSR participants above the median significantly reduced their cortisol levels, while control participants above the median trended towards even higher levels.

The study demonstrates that MBSR significantly improves psychiatric symptoms and immediate verbal recall in elderly patients with depression and anxiety, and lowers peak cortisol levels for patients with high baseline peaks.

The failure to document improvement on the other cognitive measures may reflect the insensitivity of the paper-and-pencil measures used. Computer administered tests might have proved more sensitive to change. The study is also limited by baseline differences between the treatment groups. The fact that health education participants were somewhat older, sicker, and more likely to be on medication may account for some of the differences in group improvement.

Reference:

Wetherell, J. L., Hershey, T., Hickman, S., Tate, S. R., Dixon, D., Bower, E. S., & Lenze, E. J. (2017). Mindfulness-Based stress reduction for older adults with stress disorders and neurocognitive difficulties: A randomized controlled trial. The Journal of Clinical Psychiatry.

[Link to abstract]