New research suggests that certain freely available smartphone apps featuring "mindfulness" exercises can be useful in helping some adolescents ruminate less.

Rumination refers to repetitive and negative self-focused thinking, often concerning stressful or negative past events. Called a "transdiagnostic" symptom, rumination is often seen in adolescents who are anxious or depressed, and studies have shown that it is a style of thinking that can predict the onset of both disorders.  

Mindfulness training tries to focus attention on the present moment and an awareness of what one is thinking and feeling while those thoughts and feelings are occurring—what psychologists call "metacognitive awareness."

Past studies have suggested that intensive, in-person meditation training can be useful in learning mindfulness and in mobilizing it to reduce both stress and the tendency to ruminate. These studies have often involved adults, taking courses that spanned several months.  

Christian Webb, Ph.D., a 2018 and 2015 BBRF Young Investigator at Harvard Medical School and McLean Hospital, in collaboration with Lori Hilt, Ph.D. and their colleagues, sought to test a smartphone-based mindfulness app in a group of 80 adolescents, average age 14. The team was not only interested in the degree to which teens would use the app, but also whether information about them gathered before the trial began would be useful in predicting who among them would be most likely to benefit.

The upside, the researchers noted in a paper appearing in the journal Mindfulness, was clear: "mindfulness apps offer a highly scalable, convenient, cost-effective, and potentially engaging means for teens to access brief mindfulness training via their smartphones." They noted that over 260 such apps are now available and have millions of monthly users. The apps typically consist of brief (e.g., 1- to 10-minute) guided mindfulness exercises, offered via daily "courses" that last a few weeks or sometimes longer.

To know in advance which teens are most likely to benefit from mindfulness training via an app, the team collected a range of clinical and demographic data about their subjects. To be included, participants had to have at least a moderate score on an assessment of rumination.

The app used in the study, called CARE, was downloaded on each of the participants' phones and they were taught how to use it. Based on their inputs of sleep and wake times, users are prompted via random notifications within that time window to engage the app. Each time they use the app, they take a survey to assess whether they are ruminating and to what degree, and to indicate their current mood. Participants had a higher likelihood of receiving a mindfulness exercise from the app if they reported worse mood. Mindfulness training sessions varied from 1 to 12 minutes, based on users' reply to the question of how much time they had available. Immediately following a session, users were asked to complete another survey about their current mental state.

90% (72 of 80) of the adolescents completed a 3-week trial with the CARE app, with the typical user completing a total of 29 mindfulness training sessions, an average of 1 and a half sessions per day, with session length being 1 minute 91% of the time the app was used.  

Reductions in rumination were assessed over two time intervals—"immediate" (i.e., pre- to post-mindfulness exercise) and "cumulative" (i.e., overall change in rumination over the course of the 3-week trial). The researchers found that baseline characteristics of each user accounted for up to one-fourth of the difference in outcomes between different participants.

Use of the app led to better immediate success among girls and older adolescents. Those with higher levels of rumination at the beginning of the study, and those who suppressed their emotions less had better cumulative outcomes. Levels of anxiety and depression symptoms prior to the trial did not predict who would most likely be helped.

The researchers propose that those with a more habitual tendency toward repetitive negative thinking (i.e., higher rumination) may be more likely to benefit from a targeted intervention like mindfulness training focused on cultivating attentional control and present-moment awareness. The finding about emotional suppression is more complicated to interpret given the brief nature of the mindfulness training, the authors said. It may be that "more sustained, intensive meditation practice" would help emotionally suppressed individuals more, as they "may learn and gradually internalize a more adaptive, open and receptive relationship with emotional states" through acquisition of mindfulness skills that can take time to cultivate.

Future studies should involve hundreds of subjects, the team said, and should test predictive models in both a mindfulness group and a comparative group, which might, for example, receive a mood-monitoring app instead of a mindfulness app. The authors are currently conducting several follow-up studies to address these questions.