Meditation, yoga, and relaxation techniques have gained widespread acceptance among broad segments of the population in recent years. However, meditative, mindfulness-based interventions have also been used successfully for many years in the clinical treatment of psychological and physical conditions such as anxiety, depression, and chronic pain. "The general goal of these treatments, in which meditation may play a greater or lesser role depending on the specific design, is to cultivate mindfulness, which also leads to a reduction of symptoms and, more generally, to the improvement of mental health," explains Ulrich Tran of the Department of Psychology and lead author of the review, which also involved Layla Birnbaum, Matthias Burzler, Ulrich Hegewisch, Dariga Ramazanova, and Martin Voracek.

New statistical method developed and applied for the first time

The review summarized 146 randomized controlled trials with a total of almost 11,000 participants. They were randomly assigned to a mindfulness-based treatment or a comparison group. The comparison group either received another psychotherapeutic treatment or non-psychotherapeutic care or was assigned to a waiting list. In all studies, participants’ mindfulness and mental health were recorded before and after treatment or at the beginning and end of the observation period.

To analyze their results, the review study developed and applied for the first time a novel statistical method that made it possible to systematically compare all the different treatments and comparison groups in these studies.

"Increasing mindfulness seems to be one of the elements that explain the magnitude of the positive effect of meditative and similar treatments on mental health," Ulrich Tran continues. In fact, however, the review showed that increases in mindfulness, albeit to a lesser extent, also occur in other psychotherapeutic treatments in which meditation and mindfulness do not play a role. The findings further suggested that increases in mindfulness may not only explain the magnitude of the effect of mindfulness-based treatments on mental health, but of other psychotherapeutic treatments as well.

"Mindfulness could thus be a key factor that is responsible for treatment effects," Ulrich Tran adds. Successful psychotherapies that contribute to improved mental health could be characterized by the fact that they also lead to an increase in mindfulness, whether or not they directly cultivate it. This would be an important finding for psychotherapy research, as the exact mode of action of psychotherapy remains unclear.