The effect of mindfulness-based therapy on anxiety and depression: a meta-analytic review

Authors:
HOFMANN Stefan G., et al
Journal article citation:
Journal of Consulting and Clinical Psychology, 78(2), April 2010, pp.169-183.
Publisher:
American Psychological Association

The meta-analysis was performed on thirty nine studies with data on 1,140 participants with a range of medical and mental health disorders, some of whom had elevated symptoms of depression and anxiety at baseline. The study quality was low, only 16 studies were controlled. Mindfulness-based therapy was found to be moderately effective in reducing symptoms of anxiety and depression, based on the results of the uncontrolled studies. Meta-analysis of the results of the controlled trials revealed smaller effect sizes but the results were unreliable due to the small number of studies.

Extended abstract:
Author

HOFMANN Stefan G.; et al.;

The effect of mindfulness-based therapy on anxiety and depression: a meta-analytic review.

Journal citation/publication details

Journal of Consulting and Clinical Psychology, 78(2), April 2010, pp.169-183.

Summary

The meta-analysis was performed on thirty nine studies with data on 1,140 participants with a range of medical and mental health disorders, some of whom had elevated symptoms of depression and anxiety at baseline. The study quality was low, only 16 studies were controlled. Mindfulness-based therapy was found to be moderately effective in reducing symptoms of anxiety and depression, based on the results of the uncontrolled studies. Meta-analysis of the results of the controlled trials revealed smaller effect sizes but the results were unreliable due to the small number of studies.

Context

Mindfulness-based therapy (MBT), including mindfulness-based cognitive therapy (MBCT) and mindfulness-based stress reduction (MBSR), is a psychotherapeutic treatment derived from yoga traditions that is often used for relapse prevention. Its effectiveness in reducing mood and anxiety symptoms is unclear. The aim of this study was to provide a quantitative, meta-analytic review of the efficacy of MBT for improving anxiety and mood symptoms in psychiatric and medical populations such as cancer patients who often experience symptoms of anxiety and depression as a result of their physical condition or the side-effects of treatments.

Methods

What sources were searched?
Three electronic databases were searched: PubMed, PsycINFO and the Cochrane Library. The reference lists of relevant studies and reviews were manually searched for additional material.

What search terms/strategies were used?
The term ‘mindfulness’ was combined with ‘meditation’, ‘program’ (sic), ‘therapy’, or ‘intervention’, and ‘anxi*’, ‘depress*’, ‘mood’, or ‘stress’. Databases were searched from the first available year to 1 April 2009.

What criteria were used to decide on which studies to include?
In order to be eligible, studies had to include a mindfulness-based intervention in a clinical sample of participants that had a diagnosable psychological or physical disorder and a measure of anxiety and/or mood symptoms, pre- and post-intervention. The study population had to include adult samples (18 to 65 years). Enough data to perform effect size analyses was also required. Studies were excluded if: the MBT was not delivered in person; the mindfulness programme was coupled with treatment using acceptance and commitment therapy or dialectical behaviour therapy, or; the intervention differed significantly from MBSR and MBCT in length.

Who decided on their relevance and quality?
Details of the study selection process are not included. Included studies were assigned a Jadad score of 0 to 5 to indicate their methodological quality. Two independent ratings were performed and disagreements were resolved by discussion.

How many studies were included and where were they from?
Seven hundred and twenty seven articles were initially identified; 395 were selected for further screening 122 of which subsequently underwent detailed evaluation. Thirty nine studies were included in the meta-analysis. The flow of articles through the selection process and the reasons for exclusion at each stage is presented in Figure 1. The geographical setting of the studies is not apparent.

How were the study findings combined?
Data extraction was carried out by three named authors. Effect sizes were calculated using Hedges g and interpreted according to Cohen. Pooled effect size estimates were calculated using a random-effects model. Analyses were carried out manually or by using Comprehensive Meta-analysis v.2.

Findings of the review

The 39 studies included in the meta-analysis provided data on 1,140 participants most of whom were cancer patients (9 studies); only 16 studies were controlled. Other patient populations included those with generalised anxiety disorder (5), depression (4), chronic fatigue syndrome (3), fibromyalgia (3), panic disorder (3) and a wide range of other medical and mental health conditions. Quality scores ranged from 0 to 3 with a median of 1. Study characteristics are summarised in Table 1.

Overall pre-post treatment effect sizes for the uncontrolled studies were moderate for reducing anxiety (Hedges g 0.63) and symptoms of depression (0.59). Larger effect sizes of 0.97 and 0.95 for anxiety and depression, respectively, were reported for patients with depression and anxiety. Moderate effect sizes of 0.67 (anxiety) and 0.53 (depression) were found in patients with elevated symptoms of depression and anxiety at baseline (but excluding patients diagnosed with depression and anxiety). The effect was not significantly greater than that seen in those with lower pre-treatment levels of anxiety and depression (0.53 and 0.50, respectively).

Overall effect sizes for the controlled studies were smaller: 0.50 for anxiety and 0.81 for depression in active controlled studies; 0.41 and 0.32, respectively, in waitlist and treatment as usual studies. The small number of controlled studies meant that the analyses were unreliable.

Authors' conclusions

‘Our findings are encouraging and support the use of MBT for anxiety and depression in clinical populations. This pattern of results suggests that MBT may not be diagnosis-specific but, instead, may address processes that occur in multiple disorders by changing a range of emotional and evaluative dimensions that underlie general aspects of well-being.’

Implications for policy or practice

None are discussed.

Subject terms:
therapies, therapy and treatment, anxiety, depression, mindfulness;
Content type:
systematic review
Link:
Journal home page
ISSN print:
0022-006X

Key to icons

  • Free resource Free resource
  • Journal article Journal article
  • Book Book
  • Digital media Digital media
  • Journal Journal

Give us your feedback

Social Care Online continues to be developed in response to user feedback.

Contact us with your comments and for any problems using the website.

Sign up/login for more

Register/login to use standard search filters, access resource links, advanced search and email alerts