Meditation therapy for anxiety disorders
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
To investigate the effectiveness of meditation therapy programs (to include concentrative meditation and mindfulness meditation) which are specifically designed to treat anxiety disorders in adults.
Background
Anxiety disorder is a state of pathological anxiety which is characterized by autonomy (spontaneous, occurred or minimal trigger of anxiety, tension and autonomic nervous system overactivity), intensity (in which the severity exceeds the individual's capacity to bear the level of intensity), duration, which is usually persistent or chronic, and behaviour, in which coping ability is impaired, with disabling behaviour as a consequence. According to Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM‐IV), anxiety disorders are classified into many types, including panic disorder, specific phobia, social phobia, obsessive‐compulsive disorder, post‐traumatic stress disorder, acute stress disorder and generalised anxiety disorders (APA 1994).
Anxiety disorders are among the most prevalent psychiatric condition in most populations studied. Studies have persistently shown that they produce inordinate morbidity, utilization of health care services, and functional impairment. Recent studies also suggest that chronic anxiety disorder may increase the rate of cardiovascular‐related mortality (Horwath 2000).Two major studies in the United States have estimated the prevalence rates for a variety of anxiety disorders (the Epidemiological Catchment Area (ECA) study and the National Comorbidity Survey (NCS) study). The estimated lifetime prevalence rates for individual anxiety disorders are panic disorder (2.3‐2.7%), generalized anxiety disorder (4.1‐6.6%), OCD (2.3‐2.6%), PTSD (1‐9.3%), and social phobia (2.6‐13.3%). (Blazer 1991, Kessler 1994, Eaton 1994, Kessler 1995). The prevalence of specific anxiety disorders appears to vary between countries and cultures. The lifetime prevalence rates for panic disorder ranged from 1.4 per 100 in Edmonton, Alberta, to 2.9 per 100 in Florence, Italy, with the exception of that in Taiwan, 0.4 per 100 (Weissman 1997)
The debate over the primacy of biological or psychological factors in the pathophysiology of anxiety is gradually being replaced by a pragmatic approach based on research on the relative contributions of both. A parallel, unbiased approach in treatment research has begun to examine the merits of combined somatic and psychological treatments in anxiety. There has been tremendous progress in the nonpharmacologic treatment of anxiety disorders (Barrows 2002). Cognitive‐behavioural therapies reflect a recent integration of the cognitive theories and methods associated with Aaron Beck and Albert Ellis, and behavioural therapy is based on the methods of B.F. Skinner and Ivan Pavlov. Relaxation therapy is a behavioural approach which emphasises the development of a relaxation response to counteract the stress response of anxiety. Meditation is sometimes considered to be a form of relaxation therapy, however meditation not only creates a relaxation response but also produces a higher state of consciousness which facilitates the practitioner to transform inner states such as thoughts and emotion more effectively.
Growing scientific evidence, clinical experience and community attitudes are encouraging a shift to more natural and holistic forms of therapy as alternatives or adjuncts to pharmacological approaches in a variety of conditions. Meditation has a wide range of applications, but is especially useful in treating stress and related disorders. Meditation is easily adapted to the general practice setting by adequately trained practitioners who have first hand experience of this form of therapy (Hassed 1996). Meditation may be defined as the self‐regulation of attention. It originated in ancient India more than 3000 years ago and has existed in some form in all the major religions and in many secular organisations. There are two general types of meditation: concentrative meditation and mindfulness meditation (Barrows 2002). Concentrative meditation is best represented in modern medicine by two programs, Transcendental Meditation(TM), which was introduced to the West during 1960s, and the relaxation response of Herbert Benson (Bensonian meditation) which was developed subsequently. Concentrative meditation emphasises focusing the attention onto an object and sustaining attention until the mind achieves stillness. Peaceful state of the mind is the result of continuous practice. Mindfulness meditation is another kind of meditation that emphasises open awareness to any contents of the mind that emerge. After a period of practice, the patient will develop an attentional observative capability which mindful state helps to retrain or decondition the previous pattern of reaction which is usually poorly adapted to external reality. It is represented by mindfulness‐based stress reduction programs. The techniques of mindfulness meditation with its emphasis on developing detached observation and awareness of the contents of consciousness may represent a powerful cognitive behavioural coping strategy for transforming the ways in which we respond to life events (Astin 1997).
Raskin conducted a controlled study comparing muscle biofeedback, transcendental mediation, and relaxation therapy. The study consisted of a six‐week baseline period, six weeks of treatment, a six‐week posttreatment observation period, and later follow‐up. Thirty‐one subjects completed the first part of the study and have been followed up for three to 18 months. Forty percent of the subjects had a clinically significant decrease in their anxiety. There were no differences between treatments with respect to treatment efficacy, onset of symptom amelioration, or maintenance of therapeutic gains. No evidence suggesting that the degree of muscle relaxation induced by any of the treatments is related to the therapeutic outcome. Relaxation therapies as a sole treatment appear to have a limited place in the treatment of chronic anxiety (Raskin 1980).
Kabat‐Zinn conducted a study to determine the effectiveness of a group stress reduction program based on mindfulness meditation for patients with anxiety disorders. The 22 study participants were screened with a structured clinical interview and found to meet the DSM‐III‐R criteria for generalized anxiety disorder or panic disorder with or without agoraphobia. Assessments, including self‐ratings and therapists' ratings, were obtained weekly before and during the meditation‐based stress reduction and relaxation program and monthly during the 3‐month follow‐up period. Repeated measures analyses of variance documented significant reductions in anxiety and depression scores after treatment for 20 of the subjects‐‐changes that were maintained at follow‐up (Kabat‐Zinn 1992).
Shannhoff‐Khalsa reviewed two published clinical trials for treating obsessive‐compulsive disorder(OCD) using a specific Kundalini Yoga protocol. This OCD protocol also includes techniques that are useful for a wide range of anxiety disorders, as well as a technique specific for learning to manage fear, one for tranquilizing an angry mind, one for meeting mental challenges, and one for turning negative thoughts into positive thoughts (Shannahoff‐Khalsa 04).
In terms of the adverse effects of meditation, Castillo reported that meditation can cause depersonalization and derealisation (Castillo 1990), and there are several reports about the association between meditation and psychotic state (French 1975, Lazarus 1976, Walsh 1979, Chan‐Ob 1999).
Though there is much research which has combined meditation therapy to conventional treatment in anxiety disorders, there is still a lack of reviews that provide substantial evidence on the effectiveness of meditation therapy programs, both for short‐term and long‐term effects and for acceptability in terms of concerns about adverse effects.
Objectives
To investigate the effectiveness of meditation therapy programs (to include concentrative meditation and mindfulness meditation) which are specifically designed to treat anxiety disorders in adults.
Methods
Criteria for considering studies for this review
Types of studies
All relevant randomised controlled trials comparing meditation therapy alone or in combination with conventional treatment (consisting of drug or other psychotherapy) to conventional treatment alone or no intervention / waiting list control.
Exclusion: Open trials, case series, non‐randomised trials.
Types of participants
Inclusion criteria
Adults with a primary diagnosis of DSM‐III‐R, DSM‐IV anxiety disorders (or corresponding another diagnostic criteria including ICD‐10 research diagnostic criteria for neurotic disorders) with or without another comorbid psychiatric conditions, irrespective of gender, age, race or nationality.
Types of interventions
Operational definitions of meditation: The specific techniques of mind training which have two fundamental attentional strategies
1. Concentrative meditation entails sustained attention directed toward a single object or point of focus. The aim is one‐pointed attention to a single percept without distraction in order to produce the peaceful and one‐mindedness state.
2. Mindfulness meditation ( opening‐up, insight meditation) involves the continual maintenance of a specific perceptual‐cognitive set toward objects as they spontaneously arise in awareness with nonreactive attitude. The aim is full awareness or mindfulness of any contents of the mind with equanimity.
Inclusion criteria
Meditation therapy, consisting of concentrative meditation, mindfulness meditation or combination of both
For an intervention to be accepted as Meditation Therapy:
1. It must have been described in the trial report as: meditation, concentrative meditation, opening‐up meditation, mindfulness meditation,insight meditation, meditation‐based stress reduction program, Qiqong therapy, Pranayama (Hindu breathing meditation), Transcendental Meditation, Kundalini Yoga or Anapanasathi (Bhuddhist breathing meditation), Zen, ChunDoSupBup( korean style meditation).
2. Meditation is the main intervention (in case of multi‐component relaxation therapy).
Exclusion criteria
1) Meditation therapy that is not a well‐organised program or is not specified to treat patients with anxiety disorders
2) Meditation therapy that is part of a religious/cult practice and is not specified to treat patients with anxiety disorders
Comparison conditions: may be one or combination of
1) Pharmacologic therapy: antianxiety agents mostly benzodiazepine compounds, antidepressants, adrenergic blocking agents etc.
2) Other psychotherapy: cognitive‐behavioural therapy, insight oriented psychotherapy, psychoanalysis, group therapy etc.
3) No intervention or waiting list
Types of outcome measures
Primary outcomes
1) Improvement in clinical scale of anxiety at the end of trial( continuous outcome):
Brief Outpatient Psychopathology Scale, Covi Anxiety Scale, Anxiety States Inventory, Maudsley Obsessional‐Compulsive Inventory, Hamilton Anxiety Rating Scale, Yale‐Brown Obsessive‐Compulsive Scale, Symptom Checklist‐90 etc.
2) Improvement in anxiety level specified by researcher or global improvement (categorical outcome: much improved or very much improved)
Secondary outcomes
1) Acceptability of treatment:
1.1 any adverse effects that were reported in the trials
1.2 number of subjects who reported adverse effects
1.3 Global impression of subjects to the program: Clinical Global Impression (CGI)
1.4 Other experiences related to meditation( out of body, ecstatic feeling, depersonalisation, visual experience)
2) Dropouts: the number of patients dropped out after randomization or during studies.
Search methods for identification of studies
1. Electronic databases
The following electronic databases will be searched:
‐ MEDLINE back to 1966
‐ OVID MEDLINE
‐ EMBASE
‐ PSYCLIT AND PSYCINFO
PsycLIT: from 1974‐1995 by the Cochrane Schizophrenia Group, and from 1996 to 1997 by CCDAN TSC
PsycINFO is searched quarterly from 1998
‐ LILACS 1982 and 1996 updated annually by CCDAN TSC
‐ PSYNDEX (1977‐1995) updated annually by CCDAN TSC
‐ CINAHL (Cumulative Index to Nursing and Allied Health Literature) (1982 ‐ present) are updated annually by CCDAN TSC
‐ Cochrane Controlled Trials Register Library (CENTRAL) and is updated quarterly
‐The Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register (CCDANCTR)
‐ Clinical Evidence
‐ HSTAT ( Health Services Technology Assessment Text)
The following terms will be used:
(meditation [MeSH Terms] OR *meditation[Text Word] OR "mindfulness‐based stress reduction program"[All Fields] OR vipassana[Text Word] OR Zen [Text Word] OR *yoga [Text Word] OR yogic[Text Word] OR pranayama[Text Word] OR (Sudarshan[Text Word] AND Kriya[Text Word]) OR Qi‐gong[Text Word] OR "Chi kung "[Text Word] OR Kundalini [Text Word] OR "ChunDoSunBup" [Text Word] OR shamanism[Text Word] OR shamanistic[Text Word] OR Reiki [Text Word] ) AND ("anxiety disorder* "[TIAB] OR "social anxiety disorder*"[TIAB] OR "panic disorder*"[TIAB] OR "OCD"[TIAB] OR Obsessive‐Compulsive Disorder [MeSH] OR "neurotic disorders*"[TIAB] OR "phobic disorder*"[TIAB] OR "phobic disorders"[MeSH Terms] OR *phobia[TIAB] OR "Post traumatic stress disorder*"[TIAB] OR "post traumatic stress"[TIAB] OR "Combat Disorders"[MeSH] OR "war neros*" [TIAB] OR "ac ute stress disorder*"[TIAB] OR "acute stress reaction*"[TIAB]) AND ( Controlled Clinical Trial [PT] OR Clinical Trial[PT] OR Meta‐Analysis[PT] OR systematic [sb] OR Randomized Controlled Trial[PT] OR Evaluation Studies [PT] OR Multicenter Study [PT] OR Review, Multicase [PT] OR Review of Reported Cases[PT] OR Overall [PT] OR Published Erratum [PT] OR Pilot Projects OR Prospective studies OR Cohort Studies OR Follow‐up Studies OR Comparative Study) AND "humans"[MeSH Terms]
2. Hand searching of specialist journals: the main journals have been searched by Cochrane Schizophrenia Group (CSG) and Cochrane Depression, Anxiety and Neurosis Group, Trial Search Coordinator (CCDAN TSC)
3. International conference abstracts
4. Personal communication: in order to ensure that as many as possible published or unpublished RCTs and CCTs are identified
4.1 The authors of the included studies will be consulted to find out if they know of any published or unpublished RCTs/ CCTs of meditation therapy and anxiety disorder, which have not yet been identified.
4.2 Non‐profit religious/spiritual organisation around the world ( the list is at www.meditationtherapy.com, internet mailing list) to find out whether they have conducted or know of application of meditation in anxiety patients.
5. Fugitive literature (material published is difficult to identify and because the documents or their contents may be difficult to retrieve)
5.1 Book chapters on the treatment of anxiety disorders.
5.2 Published dissertations.
5.3 Conference proceeding.
6. Checking and follow searching from references found in 1‐5
Data collection and analysis
Selection of studies
Two reviewers (KT and KW) will screen the abstracts of all publications obtained by the search strategy. A distinction will be made between:
1) Eligible studies will be those in which meditation therapy alone or in combination is compared to a different type of psychotherapy, or any active drug.
2) Non‐eligible studies will be those in which meditation therapy is examined without a control element (open trial), non‐randomised trials.
For articles that appear to be eligible RCTs, the full article will be obtained and inspected to assess their relevance based on the preplanned criteria for inclusion.
Quality assessment
In order to ensure that variation is not caused by systematic errors in the design of a study, the methodological quality of the selected trials will be assessed by two independent reviewers (KT and KW), using the criteria described in the Cochrane Handbook. The criteria are based on the evidence of a strong relationship between the potential for bias in the results and allocation concealment (Schulz 1995) and is defined below:
1. Were the inclusion and exclusion criteria clearly defined?
2. Was the allocation concealment properly done?
3. Were treatment programme, other than the interventions, identical?
4. Were important baseline characteristics reported and comparable?
5. Were the outcomes of patients who withdrew described and included in the analysis?
6. Were the outcome measures clearly defined, and valid?
Three quality categories
A : High quality ‐ all criteria met
B: Moderate quality ‐ one or more criteria only partially met
C: Low quality ‐ two or more criteria not met
Data extraction and management
Data will be independently extracted by two reviewers (KT and KW) using a predesigned data collection form. Any disagreement will be discussed with a third reviewer (PN), the decisions documented and where necessary, the authors of the studies will be contacted to help resolve the issue. All exclusion/ drop outs will be identified. In case of trials using a crossover design, to exclude the potential additive effect in the second or more stages on these trials, only data from the first stage will be analysed.
Data analysis
Dichotomous outcomes
Dichotomous outcomes will be analysed by calculating the relative risks for each trial, with the precision in each result expressed using 95% confidence intervals. The relative risks from the individual trials will be combined through meta‐analysis. When overall results are significant, the number needed to treat will be calculated ( where no clinical , methodological or statistical heterogeneity has been identified) by pooled analysis of the overall relative risk with an estimate of the prevalence of the event in the control group of the trials.
Continuous outcomes
Data on continuous outcomes will be analyzed in RevMan 4.2 (Review Manager 2002) . Considering that the data using standardized mean difference are frequently skewed, the means not being the centre of the distribution. The statistics for meta‐analysis are thought to be able to cope with some skew, but are formulated for parametric data. To avoid this potential pitfall the following standards will be applied to all data before inclusion:
1. Standard deviations and means have been reported or obtained from authors.
2. For data with finite limits, such as the endpoint scale data, the standard deviation (SD), when multiplied by 2, is less than the mean. Otherwise the mean is unlikely to be an appropriate measure of the centre of the distribution (Altman 1996). The reviewers will report data that do not meet the first or second standard in the 'other data' tables.
For change data (endpoint minus baseline) in the absence of individual patient data, it is impossible to know if data are skewed. Where both change and endpoint data are available for the same outcome category, endpoint data only are presented. Authors of studies reporting change data only will be contacted for endpoint figures. Non‐normally distributed data will be reported in the 'Other data types' tables.
Subgroup analysis
Due to likely differences in response, rather than undertaking an overall pooled analysis, the data will be analysed in subgroups according to the following categories:
1. type of meditation ( concentrative or mindfulness meditation)
2. different type of anxiety disorders
3. short term or long term effect of meditation
Analysis of Heterogeneity
Heterogeneity can occur from many sources. An important aspect of every meta‐analysis is to consider and emphasise the existence of heterogeneity and to take account of this in the interpretation of results. Sources of heterogeneity (clinical heterogeneity) can be divided in to two groups: biologic and methodologic .
Biologic:
1. Characteristic of patients: age, socioeconomic, education
2. Type of anxiety disorder: Generalised anxiety disorder, panic disorder, phobic disorder etc.
3. Disorder severity and chronicity: mild, moderate, severe
Methodologic
1. Type of meditation
1.1 Techniques: concentrative, mindfulness meditation or combination
1.2 Intensity of practice: daily, many times a day, duration of meditation per session
2. Follow up period: at the end of trial or a period after trial
3. Multi‐component intervention: drugs, counselling, psychotherapy etc.
Strategies for exploring heterogeneity
1. Identifying methodologic differences between studies
2. Identifying biologic differences in study sample
3. Subgroup analysis
4. Meta‐regression if enough data are available
In case of homogeneity of studies result, the fixed effect model will be used in meta‐analysis
Sensitivity analysis
A sensitivity analysis will be undertaken to test the effects of assumptions made by the reviewers by examining the influence of the following on the results of the statistical analyses:
1. the effect of the quality criteria
2. comorbid depressive disorder
3. concomittant physical disorder
4. blinding of raters
Note that the sensitivity analysis may well not be possible due to the data will be limited.
Publication bias
The funnel plot (Light 1984, Egger 1997) will be used to determine publication bias, by plotting the effect size against sample size. Publication bias results when trials with negative results are not published and fail to be included in the review. Although not conclusive, where sufficient data are available, a funnel plot can suggest whether publication bias might exist.
