A new study from researchers at Carnegie Mellon University shows that a mindfulness app, used for two weeks in daily 20-minute increments, measurably reduced stress compared to a control app. 

Testing the impact of a smartphone intervention on stress wasn't the primary purpose of the study; instead it sought to prove that the specific mindfulness paractices of monitoring and acceptance were effective.

"Not only were we able to show that acceptance is a critical part of mindfulness training, but we've demonstrated for the first time that a short, systematic smartphone mindfulness program helps to reduce the impact of stress on the body," study leader Emily Lindsay said in a statement. "We all experience stress in our lives, but this study shows that it's possible to learn skills that improve the way our bodies respond to stress with as little as two weeks of dedicated practice. Rather than fighting to get rid of unpleasant feelings, welcoming and accepting these feelings during stressful moments is key."

In order to test the impact of the app, 144 participants were randomized to three apps from the same developer, 01 Expert Systems. All three apps consisted of 20-minute audio lessons, but the content of the lessons differed. One taught just the strategy of monitoring one's feelings and sensations, one taught monitoring plus acceptance of those feelings, and the third, the control group, taught basic coping mechanisms not connected to mindfulness.

After two weeks, participants were subjected to stressful situations wherein they needed to quickly invent and deliver a five-minute speech or do math in front of examiners for five minutes. During and immediately after these tests, participants' blood pressure and cortisol levels were measured as proxies for stress. The mindfulness and acceptance app reduced systolic blood pressure and cortisol levels substantially.

"We have known that mindfulness training programs can buffer stress, but we haven't figured out how they work," David Creswell, associate professor of psychology in CMU's Dietrich College of Humanities and Social Sciences, said in a statement. "This study, led by Emily Lindsay in my lab, provides initial evidence that the acceptance training component is critical for driving the stress reduction benefits of mindfulness training programs."

In the study writeup, published in the journal Psychoneuroendocrinology, researchers noted that the use of an app had a number of benefits for researchers.

"This study has a number of notable features," researchers wrote. "It is the first study to show that brief smartphone-based mindfulness training can impact objective biological stress outcomes. This smartphone format also provided a platform for dismantling the active components of mindfulness training, which allowed us to address mechanistic questions. By tightly controlling the intervention content, we were able to observe the unique contributions of attention monitoring and acceptance training beyond non-mindfulness-specific treatment elements (i.e., stress management and reappraisal skills in the placebo comparison program)."

Furthermore, researchers wrote, the smartphone form factor led to extremely low attrition (3 percent) and high adherence (96 percent) in the study.

"These findings demonstrate value in implementing smartphone-based mindfulness interventions for a large proportion of stressed adults who lack resources for more expensive, intensive, and potentially inaccessible in-person mindfulness programs," researchers wrote.

01 Expert Systems is planning to create a commercial app based on the app administered to the monitoring and acceptance group, for offering to payers and employers.