Objectives
The objective of this study was to examine the effectiveness of mindfulness-based stress reduction (MBSR) on depression, anxiety and psychological distress across populations with different chronic somatic diseases.
Methods
A systematic review and meta-analysis were performed to examine the effects of MBSR on depression, anxiety, and psychological distress. The influence of quality of studies on the effects of MBSR was analyzed.
Results
Eight published, randomized controlled outcome studies were included. An overall effect size on depression of 0.26 was found, indicating a small effect of MBSR on depression. The effect size for anxiety was 0.47. However, quality of the studies was found to moderate this effect size. When the studies of lower quality were excluded, an effect size of 0.24 on anxiety was found. A small effect size (0.32) was also found for psychological distress.
Conclusions
It can be concluded that MBSR has small effects on depression, anxiety and psychological distress in people with chronic somatic diseases. Integrating MBSR in behavioral therapy may enhance the efficacy of mindfulness based interventions.
Many chronic somatic diseases are highly prevalent in industrialized countries. About 45% of healthy 40-year-old men and 30% of healthy 40-year-old women, for example, will develop coronary heart disease in later life [1]. It is estimated that 85% of older adults is affected by one or more chronic diseases [2]. In more recent studies that defined chronic pain as pain of >3 months duration, prevalence rates of chronic pain ranged from 10.8–23.7% [3] and [4]. For mental disorders, the presence of chronic somatic diseases is a risk factor. An increased risk of developing an anxiety disorder has been found among people with arthritis [5], coronary heart diseases [6]. An increased prevalence of depression has been found for many chronic physical somatic diseases in both cross-sectional and longitudinal studies, e.g., cardiovascular diseases [6], cancer [7], and arthritis [5]. It is estimated that between 20% and 30% of cancer patients will experience depressive symptomatology [8] and [9].
Mindfulness-based stress reduction (MBSR) is a treatment for psychological distress, depressive symptoms, and anxiety for people with chronic disease that is rapidly growing in popularity in the United States. Developed by Kabat-Zinn [10] and [11], the MBSR program consists of 8–10 sessions for groups of up to 30 participants. Central here is the practice of mindfulness. Mindfulness is the skill to non-judgmentally observe emotions, sensations, or cognitions. Mindfulness is moment-to-moment awareness and is trained through meditation exercises that have been adapted from Buddhist traditions. Besides these meditation skills, yoga exercises and psycho-education are also part of the program. Whereas MBSR was originally developed for people with chronic pain, it was later also applied to people with chronic diseases such as cancer [12], fibromyalgia [13], and heart failure [14]. Apart from MBSR, mindfulness is also an important component of other treatments such as acceptance and commitment therapy [15], dialectic behavioral treatment [16], and cognitive therapy [17].
Two meta-analyses have so far studied the effects of MBSR on mental health [18] and [19]. Grossman et al. [18] conducted a meta-analysis of 20 controlled and uncontrolled studies on the effects of MBSR on physical and mental health of medical and non-medical samples. They found an effect size of d=0.54 for controlled studies on mental health. No effect sizes for specific symptomatology (depression, anxiety) were reported. Baer [19] included both controlled and uncontrolled studies focusing on populations with somatic diseases, clinical populations, and nonclinical populations. Effect sizes of d=0.70 for anxiety (eight studies) and d=0.84 for depression (five studies) across the different populations were reported. Average effect sizes at posttreatment across medical and psychological outcomes of d=0.37 were found for patients with chronic pain and d=0.55 for patients with other somatic disorders. Both meta-analyses included only two published, controlled studies on the effects of mindfulness on mental health in populations with somatic diseases. No effect sizes for depression and anxiety in these populations were calculated. Qualities of studies that might moderate the effects on mental health were not systematically analyzed.
On the basis of the fact that, in recent years, many more controlled studies on MBSR in somatic medical populations have been published, we decided to conduct a new meta-analysis on the effects of MBSR in people with chronic somatic diseases. The objective was to analyze the overall effects of MBSR on psychological distress, depression, and anxiety.
