The Effectiveness of Meditation-Based Interventions on Psychiatric Disorders

By

Umisha Gheewala


Bsc (Hons.) Business Administration and Psychology


March 2010


Background
This section defines what is meant by psychiatric disorders and how they are categorised. Existing interventions for curing psychiatric disorders are discussed, followed by an introduction to meditation and its relevance as a possible intervention for psychiatric disorders.

Psychiatric Disorders
Psychiatric disorders can be defined as psychological or behavioural patterns resulting in distress or disability. These are seen as abnormal and not part of typical development or culture. These can be reflected by significant distress, lower self esteem, impairing ability to function in life, and/or significantly increasing risk of death, pain, disability, or loss of freedom (Claridge and Davis, 2002)

According to Rubia, 2009, Psychiatric disorders are on the increase worldwide and account for 31% of the total disability. Over a third of people in most countries report meeting criteria for the major categories of psychiatric disorders at some point in their life.

For the purpose of this review, psychiatric disorders have been classified into the following fundamental categories.
o Anxiety disorders: anxiety is a distressing, unpleasant emotional state of nervousness and uneasiness (Merck, 2009). These disorders may be marked by irrational fears, recurring panic attacks, fears related to traumatic events and obsessive thoughts and compulsive disorders (Frude, 1998).
o Mood disorders and depression: marked by profound sadness, low self esteem various behavioural changes in which periods of depression alternate with periods of mania (excessive engagement in pleasurable but unhealthy activities) (Frude, 1998).
o Cognitive Disorders: often caused by brain damage or deterioration and include acute conditions such as delirium and chronic disorders such as dementia (Frude, 1998).
o Schizophrenic disorders: The psychoses involve a loss of contact with reality. There is usually a marked impairment of emotional and social functioning (Frude, 1998) and Psychotic symptoms include delusions, hallucinations, disorganized thinking and speech, and bizarre and inappropriate behaviour (Merck, 2009).
o Personality disorders: personality disorders are pervasive, inflexible, and stable patterns of behaviour that cause significant distress or functional impairment. They may include a chronic disregard of other people rights and interests or a preoccupation with punctuality, precision and perfection and pays attention to trivial matters (Frude, 1998).

Other categories include substance disorders, eating disorders and childhood disorders, These are not within the scope of this particular review, they are however a possible area for future research.

Common Current Intervention Used for Psychiatric Disorders
Interventions used to cure and reduce symptoms of psychiatric disorders vary between the type and intensity of the disorder. They usually include types of psychotherapy and pharmacological medication.

Psychotherapeutic models involve a therapist and client relationship, in a group or on a one to one basis. An examples Cognitive Behaviour Therapy (CBT) which aims to directly change patterns of thinking or behaviour that underly people’s difficulties and so change the way they feel (Champion & Power, 1992). According to DeRubies et al. (2005), CBT has been shown to be effective in many cases especially in treating acute depression and anxiety disorders and reducing relapse , however waiting lists for individual therapy are lengthy in most healthcare settings (as cited in Kenny & Williams, 2006).

An alternative therapy, psychoanalysis, aims to provide insight of the unconscious mind to the patient by bringing it into awareness. Whilst improvements in the patients are found, psychoanalysis is reported to be too intrusive, intense and ambiguous for some patients. Such therapies have been criticized for being too lengthy, expensive and requires a significant level of involvement and commitment from the patient (NHS, 2010). Furthermore the ‘dose effect curve’ states that therapy may be beneficial only up to a certain point where after dependency on a therapy may enforce belief about helplessness with in a patient (Dryden, 2007).

Pharmacological medication has been shown to bring rapid and substantial relief in the short run. Examples include Benzodiazepines for anxiety, Tricyclics for depression and Lithium mood disorders. However, intolerable side effects have lead to dissatisfaction with current medications (Zylowska, 2008). Goodman et al (1992) cited in Shannhoff–Khalsa (2004) reported that one third of patients who take drugs (such as Serotonin) are unimproved after an apparently adequate drug treatment, yielding a ‘drug treatment resistant’ patient. Even those that are responsive to medication produce only a 30-60% symptom reduction and patients tend to remain chronically symptomatic to some degree despite the best pharmacologic interventions (Jenike, 1992 cited in Shannhoff-Khalsa, 2004). Symptom relief is often dependent on continuing medication, therefore drugs cannot be said to provide a sustainable cure for disorders (Frude, 1998).

The existing interventions discussed, have been shown to have mixed results.There is no long term cures to alleviate or prevent the onset and relapse of the symptoms of psychiatric disorders (Rubia, 2009). It is for this reason that this literature review seeks to synthesis the existing literature on newer modalities of intervention such as meditation.

Meditation
The practice of meditation has been a long standing tradition in many Asian countries and originates from ancient eastern scriptures and spiritual teachers such as Patanjali, Yogi Bhajan and Buddha. Meditation “is different from sleep or relaxation, but rather an altered state or trait of consciousness characterized by expanded awareness, greater presence, and a more integrated sense of self” (Davis and Gold, 1998, p.73). Meditation can be described as transforming the mind and “bringing one’s complete attention to the present experience on a moment-to-moment basis” (Marlatt& Kristeller, 1999, p.68 cited in Baer, 2003).

There are numerous meditation techniques that have been practiced over centuries, each varying in their structure, process and style. There are two broad categories of meditation; 1) technique that involve focussed attention to parts of the body, the breath, an object, a mantra or music. This is common in several techniques such as Buddhist practices, Kundalini yoga (KY), Sahaja yoga (SY) and Transcendental meditation (TM). 2) techniques that focus on expanding the attention non-judgmentally on the moment to moment experience and observing thoughts and feelings from a meta-cognitive awareness. This type of meditation is common in Vipassana (VP) and Zen Buddhist practices (Ivanovski and Malhi, 2007).

The essence and aim of meditation is to delve into the hidden parts of the mind, conscious and unconscious, in search of answers to questions revolving around the meaning of life and the purpose of existence (Project-meditation, 2007). The purpose of meditation is to create peace of mind, reduce suffering, improve health and well being, and cultivate freedom from ‘thought pollution’ (Austin, 1998). Rubia (2009) noted that the aim of meditation is to reduce and eliminate irrelevant thought processes through training of internalized attention.

The following benefits of meditation reported by individuals have been found;
- Physical relaxation (Miller et al., 1995)
- Non attachment (Kabat-Zinn, 2000)
- Stress reduction (Gross, et al., 2009)
- Anger reduction (Singh et al., 2007)
- Improved mood and emotional stability (Williams et al., 2008)
- Enhanced concentration (Kabat-Zinn, 2000)
- Decreased rumination (Teasdale et al., 1994)
- Increased awareness and insight and spirituality (Austin, 1998)

Meditation can be practiced by almost everyone including men and women of all ages from all walks of life, educational levels, and religious backgrounds (Austin, 1998). More recently its popularity has started to penetrate into the ‘western world’. Large institutions are beginning to implement meditation techniques to improve their effectiveness such as the Bolivian army implementing techniques of KY in 2009 (Sikhnet, 2010). The US Peace Government is incorporating the TM program into their agenda (US Peace Government, 2010) and VP meditation has been implemented in more than eight prisons in the US, aiming to bring inner change within prisoners (Vipassana Research Institute, 2010).

The relevance of Meditation as an Intervention for Psychiatric Disorders
According to Koszycki et al. (2004) meditation has in recent years received considerable attention as a potential adjunct or stand alone intervention for psychiatric disorders. The perceived benefits of meditation on the physical, cognitive and emotional level have made meditation an attractive method for the possibility of curing or/and reducing symptoms of psychiatric disorders. Meditation can be self taught, is highly accessible, inexpensive and presumably free of side effects, making it a practical and attractive intervention (Shanhoff-Khalsa, 2003) Meditation can be taught in non psychiatric setting by health care professionals and educators from a broad range of disciplines; thus is an appealing option for individuals who are reluctant to access mental health services, due to embarrassment of discussing fears which may result in poor detection of the disorder by health professionals (Koszycki et al., 2004).

Meditation may allow an individual to ‘work on’ distressing issues by practicing the techniques and not necessarily discussing it. Meditation is also appealing for those that are unable to take medication (i.e. pregnant women) (Lee et al., 2006). Meditation-based interventions are an important area for research and may have far reaching implications of dealing with the increasing prevalence of psychiatric disorders for the future (Gross et al., 2009).

Existing ways in which Meditation is Already Being Used as An Intervention for Psychiatric Disorders
A small number of professional, manualised and structured group programs have been developed which employ meditation techniques in order to alleviate suffering associated with physical, psychosomatic and psychiatric disorders (Grossman et al., 2004). Two such programmes are:
- Mindfulness-based stress reduction (MBSR) MBSR aims to cultivate moment-to-moment awareness by reducing judgement, thinking about past events and/or future possibilities and promoting positive regard for self and others which is predicted to reduce distress associated with psychiatric disorders (Sulivan et al, 2009)
- Mindfulness–based Cognitive Therapy (MBCT) combines meditation with aspects of CBT (Williams et al. 2008). It aims to increase accessibility to effective relapse prevention using meditation-based techniques and teaches participants to disengage from those cognitive processes that may render them vulnerable to future episode especially in depressed patients (Kenny & Williams, 2006).

According to Bishop (2002) interest of such programmes has grown exponentially in the West since their introduction approximately 20 years ago. Neither methods were originally developed to treat specific disorders but were initially taught to improve health and wellbeing for common complaints. They were later tested and used for this purpose (15 Baer, 2003). It is important to note that when meditation is used as an intervention for psychiatric disorders, spiritual and religious aspects are excluded.

Method of literature search
The Web of Knowledge in Aston E-Library was used as the main search platform were used to identify articles that were relevant to the topic question

The majority of articles were found in the following databases: Pub Med, Science Direct, Swetswise, Willey and American Psychological Association. A total of 89 articles were retrieved via the search. Article abstracts were then read and f a link was established between the effectives of meditation and psychiatric disorders, and if the article was related to the categories of psychiatric disorders that have been selected for this review (2.0) the article was saved.

Relevant citations within these articles were searched to identify further related articles. This snow balling technique generated additional articles whose abstracts were also read and filtered according to the above criteria. This proved to be a very effective method in selecting relevant articles. 45 articles were considered as passing this stage of screening.

Finally a Screening Criterion was Used to Ensure Appropriateness of Articles for this Literature Review Inclusion criteria
The criteria used to assess whether the article would be considered was as follows;
- Mindfulness or meditation was described as a technique which teaches detachment, attention and awareness of the present moment.
- No discrimination between recent and old articles, allowing a comprehensive overview of some recent adaptations to meditation and some original authentic techniques of meditation.
- Quantitative and qualitative outcomes were considered in order to give a broad view on the topic and account for the nature of meditation being that of something experiential which cannot always be captured in statistics.
- Sample size was not discriminated against. Case reports with sample size of one and large group sample sizes were both included.
- Both, controlled group studies and uncontrolled group studies were included, as otherwise studies for evaluation were minimal, and effects which may exist may not be considered
- Similar literature reviews were also included in order to see how similar areas and previous work analysed their findings

Exclusion criteria
Criteria to determine exclusion from this review consisted of the following;
- Not available in English
- Denied access to full text
- When meditation was taught at irregularly intervals and/or over a period of less than four sessions in total.
- Samples of children, substance abused patients or eating disorder suffers were excluded as these topics were beyond the scope of this review.
- Interventions that may have only taken ideas from meditation and formulated its own practice where excluded, for example Dialectical Behavioural Therapy (Linehan & Dimeff, 2001). Excluding these articles allowed a more specific investigation on ‘pure’ meditation as others forms may distort results
- Physical disorders such as chronic pain were not included as this review focuses on mental and emotional deficits. Studies investigating individuals with physical pain was included only if the effect of meditation was being tested on a secondary symptoms, such as depression.
- General well being, quality of life or subjective benefits among non clinical patients was excluded

Findings
A total of twenty two articles were reviewed and met the above criteria.
The following findings were identified.

Effectiveness of Meditation on Anxiety Disorders
Of the twenty two studies that were chosen for this review, nine articles investigated the effectiveness of meditation-based interventions on clinical patients diagnosed with an anxiety disorder.

The anxiety disorder Obsessive Compulsive Disorder (OCD) has been referred to as a "waking nightmare" and is the fourth most common psychiatric disorder and the tenth most disabling (Rapport, 1990 cited in Shannahoff-Khalsa, 2004). Several studies agree that meditation can have a positive effect on patients with OCD (Shannahoff –Khalsa, 2004; Patel et al., 2007; Shannahoff-Khalsa, 2003; Kim et al., 2009). Shannhoff-Khalsa (2004) reports, meditation effectively and significantly reduced the level of OCD. After one year of practicing KY, four out of five patients who completed the meditation training were off medication for periods between nine and nineteen months with lasting improvements.

In Shannahoff-Khalsa’s (2004) group study, four out of twenty one patients scored "0" or "1" on the Yale Brown Obsessive Compulsive Scale (YBOCS) which may be considered as a state of remission. A case report by Patel et al. (2007) gave evidence of a nine point reduction in the YBOCS, representing a meaningful and reliable change. This patient reported that he was able to function normally and returned back to work with less worry and an increased sense of security to pursue activities and tasks that were important to him. While significant results may support the use of meditation, the report was with a single individual and thus not generalizable.

In contrast, Lee et al. (2006) investigated the effects of meditation on forty six patients with a variety of anxiety disorders and argues that there was no significant reduction in OCD scores. However, careful analysis of the statistics revealed a mean decrease on the SCL-90-R subscale from 11.1 to 8.0 demonstrating some positive effect (Lee et al., 2006, p.192). In addition this study did not use the the diverse methods of measurements as the Shanhoff-Khalsa (2004) who used six scales to test OCD yielding arguably more accurate results including, YBOCS, SCL90R-OC, GSI Scales, POMS, PSS, PIL scales.

The majority of evidence from the articles chosen for review support the reduction of OCD symptoms and demonstrate impressive results to establish a strong relationship between meditation and this anxiety disorder. According to Patel et al. (2007) meditation training may act as a potential standalone treatment for OCD. However the effectiveness of meditation would be relevant only if it is better than alternate or current interventions.

Meditation showed positive results for the improvement of patients with General anxiety disorder (GAD) and panic disorder in three studies. Kabat-Zinn et al. (1993) and Miller et al. (1995) showed that after an eight week MBSR programme on twenty two GAD suffers the mean Becks Anxiety Indicator (BAI) reduced from 21.41 to 8.29 and the Hamilton Rating Scale for anxiety reduced from 25.65 to 17.29 on a three month follow up (Miller et al., 1995, p.195). The number of panic attacks decreased by 67% and the severity of panic attacks decreased by around 81% (See Figure. 2) These scores were maintained in a three year follow up providing of the long term impact of MBSR programme used. Kim et al. (2009) investigated a mixed population of 46 individuals with GAD or panic disorder, the intervention of MBCT or MBSR programmes created improvements on all anxiety scales relative to the control comparison group of educational programmes.

Effectiveness of Meditation based Interventions Compared with Alternative Interventions (therapies and pharmacological)
The effectiveness of meditation-based interventions compared to alternative therapies have had mixed results. Firstly, four of the nine studies did not use a control group thus limiting their support for the preference of using meditation instead of an alternative intervention.

There is evidence for the long term sustainable impact of meditation-based interventions in anxiety. Six out of nine studies engaged in some form of ‘follow up data’, ranging from a minimum of three months follow up to a maximum of three years. The reduction in anxiety after treatment was successfully maintained in their findings which provide influential support that relief was not simply short term. Ideally the three studies that did not consist of longitudinal studies should be followed up to identify if the implications of meditation in the long run. Recent and relatively thorough studies such as, Gross et als’. (2009) study cannot yet be followed up yet. Longitudinal studies that exceed three years must be done in the future.

Another key finding is that the overall drop-out rates for patients with anxiety disorders being treated by meditation is low. In nine studies consisting of two hundred and fifty one patients in total with an anxiety disorder, only twenty three individuals dropped out before completing the meditation-based intervention (9.1%). This may have been due to high satisfaction ratings of the techniques, or the method of recruiting which was mostly voluntarily and through advertisement. These two factors will be discussed in more detail in section 7.1. Unfortunately the drops-out rate documented have not been compared to the rates of other therapies. However, in future studies, it would be valuable to compare this percentile to other therapy dropout rates which has been overlooked in these studies.

There has been no work done on the effect of meditation on phobic disorders. Without any empirical evidence, it is not recommended that patient who suffers from a phobia attempt to deal with symptoms by using meditation alone. Due to the lack of studies, common interventions such as ‘exposure’ in behavior therapy should be continued, this gap in research is considered for future research.

Control studies provide useful comparisons to some extent and it can be inferred that based on the evidence, meditation is more effective then RT. In the future it is important to conduct more studies comparing meditations effectiveness with alternative therapies. In order to be fair, the training time of each intervention and the differences of the disorder onset should be controlled providing a basis for a comprehensive comparison. Furthermore there are no studies attempted to compare meditation-based intervention to any pharmacological treatment, again limiting conclusions.

Summary
Despite the limitations of the available current studies noted, improvements in a broad range of scores showing impressive and sustainable results. Thus, in conclusion the hypothesis of this review holds for effectiveness of meditation for anxiety disorders.

Effectiveness of Meditation on Mood Disorders and Depression
Seven out of the twenty two articles chosen for review tested the effectiveness of meditation on depressed patients. (Kenny & William, 2006; Sulivan et al., 2009; Williams et al., 2008; Sephton et al., 2006; Teasdale et al., 1994; Miller et al., 1995; Kabat-Zinn et al., 1992) A significant amount of evidence demonstrated that meditation had a positive impact on the reduction of depressive symptoms

Kenny and Williams’ (2006) study found that sixty five out of seventy nine patients with depression showed significant improvements in Beck Depression Indicator (BDI) scores after having followed a two and half year MBCT programme. The results were compelling and stated that before treatment, fourteen patients had scores of 30 BDI or above and after treatment only four patients had a score of 30 BDI or above.
There is evidence to demonstrate the reduction in depression when it is experienced as a secondary outcome of a physical illness such as fibromyalgia and chronic heart failure (CHF) (Sephton et al., 2006; Sulivan et al., 2009).

The significant reductions in depression and mood scores in Sulivan et als. (2009) study was thought to lead to an improvement in physical symptoms of CHS measured by Kansas City Cardiomyopathy Questionnaire Symptom Scale (p=0.033). This encouraging finding suggests that meditation may be useful in hospitals for relieving part of their suffering for patients with other physical chronic disorders. This may be because meditation disconnects response to pain from ruminations about pain and consequent development of depressive symptoms (Sephton et al., 2006). The topic of physical disorders is not covered in detail in this review but it is certainly a point for consideration regarding future research.

The ability of meditation-based interventions to maintain a sustainable impact for depression was convincingly supported by five out of the seven studies cited earlier that confirm the long term impact (2months to 3 years) of meditation on depressive symptoms. Teasdale et al. (1994) investigated the mechanism and process of how meditation may help to prevent relapse and sustain this long term impact. They propose that as meditators acquire the skill to deploy the 'central engine' resources to process information or focus on a neutral object such as breath, the resources necessary to support ‘depression enhancing’ or ‘depression maintaining process cycles’ are less available.

Repeated practice will ‘train’ the mind to return to object of focus when the mind 'wanders off' to spontaneously occurring problematic thoughts and worries. Accepting, acknowledging and 'letting go' of a problem related thoughts and returning attention to the breath implies postponing or even relinquishing the attempt to realise the intention to which the thought relate. However, the studies do not state the amount of practice needed to determine long term effect. However the long term effect of meditation may vary depending on the amount of practice and severity of symptoms which is not considered in these studies. This will be discussed later in section 7.3.

Williams et al. (2008) carried out a well designed, randomized and controlled study investigating the relationship between MBCT and mood disorders. This study was distinct in its investigation of unipolar and bipolar patients.
There is evidence to demonstrate the reduction in depression when it is experienced as a secondary outcome of a physical illness such as fibromyalgia and chronic heart failure (CHF) (Sephton et al., 2006; Sulivan et al., 2009). The significant reductions in depression and mood scores in Sulivan et als. (2009) study was thought to lead to an improvement in physical symptoms of CHS measured by Kansas City Cardiomyopathy Questionnaire Symptom Scale (p=0.033).

This encouraging finding suggests that meditation may be useful in hospitals for relieving part of their suffering for patients with other physical chronic disorders. This may be because meditation disconnects response to pain from ruminations about pain and consequent development of depressive symptoms (Sephton et al., 2006). The topic of physical disorders is not covered in detail in this review but it is certainly a point for consideration regarding future research.

The ability of meditation-based interventions to maintain a sustainable impact for depression was convincingly supported by five out of the seven studies cited earlier that confirm the long term impact (2months to 3 years) of meditation on depressive symptoms. Teasdale et al. (1994) investigated the mechanism and process of how meditation may help to prevent relapse and sustain this long term impact. They propose that as meditators acquire the skill to deploy the 'central engine' resources to process information or focus on a neutral object such as breath, the resources necessary to support ‘depression enhancing’ or ‘depression maintaining process cycles’ are less available. Repeated practice will ‘train’ the mind to return to object of focus when the mind 'wanders off' to spontaneously occurring problematic thoughts and worries.

Accepting, acknowledging and 'letting go' of a problem related thoughts and returning attention to the breath implies postponing or even relinquishing the attempt to realise the intention to which the thought relate. However, the studies do not state the amount of practice needed to determine long term effect. However the long term effect of meditation may vary depending on the amount of practice and severity of symptoms which is not considered in these studies. This will be discussed later in section 7.3.

Williams et al. (2008) carried out a well designed, randomized and controlled study investigating the relationship between MBCT and mood disorders. This study was distinct in its investigation of unipolar and bipolar patients.5.3 Effectiveness of meditation on cognitive disorders

Of the 22 studies reviewed, there were no specific clinical studies carried out for dementia or delirium sufferers and cognitive disorders. A number of studies however report benefits of meditation on cognitive behaviour based on individual case studies. There is no statistical evidence available to prove or disprove the hypothesis for this category of psychiatric disorders.

According to Flicker (2009), mental disorders such as dementia are typically characterized by cognitive-attention problems, and it is thought that improvements in cognitive functioning, such as memory, attention and motor functioning can potentially reduce the risk of dementia and delirium. Even though there has been no clinical population tested, several studies have demonstrated a positive change in cognitive functioning (Rubia, 2009; Zylowska et al., 2008; Bailjal and Gupta,2008; Baer, 2003 and Grossman et al,. 2003)

Grossman et al. (2003) reviewed twenty articles for the general health benefits of MBSR, and reported significant cognitive improvements in, self control, concentration, memory and over selectivity. Bailjal and Gupta (2008) claims that meditation leads to an enhancement of certain attention capabilities and improvements in cognitive ability due to functional and structural plasticity of the brain systems. Rubia (2009) also investigates changes in brain activity and concluded the following;
- Experienced meditators show less cognitive activity in Positron emission tomography scans (PET) and Electroencephalography scans (EEG)
- Enhanced high-amplitude and synchronized gamma exist after meditation sessions
- The thickness of the right prefrontal regions increases. In one study, it was shown that 40-50 year old meditators were comparable to the thickness in 20-30 years old.

According to Rubia (2009) these persuasive observations have positive implications for cognitive functioning such as attention, memory recall, control and reaction time. EEG studies show that different meditation techniques may elicit very different brain activation patterns based on the specific technique. This makes it challenging for Rubias’ (2009) study to draw conclusions for the effectiveness of all meditation techniques.

Certainly more direct head to head comparison between different meditations techniques are needed to understand the neural network that are specific to each type of meditation. In addition, the sustainable effects of cognitive functions need to be determined by longitudinal studies of brain scans. Further, Rubias’ (2009) study does not investigate the amount of time or practice needed before any brain changes are observable.

ADHD in adults is classified as a behavioral disorder, however will be discussed in this section as it has also been associated with cognitive impairments (Zylowska et al 2008). ADHD suffers may include demonstrate deficits in monitoring of attentional resources, response inhibition, error monitoring and attentional disengagement (Bailjal and Gupta 2008). Individuals with ADHD have a deficit in executive-control processes and are also characterized by large moment-to-moment fluctuations in cognitive control (Rubia, 2009). Rubia (2009) notes that Sahaj Yoga meditation reduce symptoms of hyperactivity, sustained attention, and an increase reported moment-to-moment awareness.

Zylowska et al. (2008) tested twenty four adults and eight adolescents with ADHD and found that an eight week programme of meditation training produced significant positive changes in the reduction of symptoms. For example, eighteen of the twenty four (78%) participants reported a reduction in their total ADHD symptoms, with seven of the twenty four (30%) participants reporting at least a 30% symptom reduction (considered a clinically significant improvement).

Zylowska et al (2008) notes that the high adherence rate (88%) in their study suggest that meditation-based intervention is plausible for the use within ADHD patients. However, there is no comparison of this adherence rate to other interventions propose a weakness in their conclusions. Furthermore, Zylowska et al. (2008) study was uncontrolled, used a small sample size which consisted of atypical, white, educated, women thus limiting the level of generalisability. Bailjal and Gupta (2008) who support the relationship between meditation and ADHD and improvement in cognitive functioning, however they correctly note that conclusions are limited and future research in this area should be controlled and longitudinal.

Summary
Even though there is a lack of direct clinical data, some convincing support of the effectiveness of meditation on cognitive performance can be drawn which support the hypothesis of the review.

Effectiveness of Meditation on Schizophrenic Disorders
The effectiveness of meditation in schizophrenic disorders is also relatively unclear as there have been no clinical tests specifically on diagnosed patients of schizophrenic disorders to demonstrate any definite relationship. This could be for several reasons: it may be challenging to attract schizophrenic patients due to their ‘impairment in social functioning’ leading to an unwillingness to participate in group intervention (Frude, 2008). Or the infancy of meditation-based interventions means that widespread testing on all disorders has not yet been completed.

Alternatively, current interventions such as antipsychotic medication and CBT may be working effectively which means there is no need to search for alternative modalities. However the latter reason may be proved wrong as research shows that out of 100 people with schizophrenia:
- 50 people will experience a relapse of symptoms within two years.
- 30 people will never be free of symptoms even after treatment, though the severity of symptoms can fluctuate over time.
- 20 people will remain resistant to treatment and will require constant support and supervision (NHS, 2010),

There were three contrasting findings related to schizophrenia in the literature. Firstly, the study carried out by Kim et als’. (2009) study on forty six patients with anxiety disorder stated that MBCT showed no significant improvement in somatisation, paranoid ideation or psychotisism subscale scores of the SCL-90-R which has been specifically related to schizophrenia (Frude, 1998). This suggests that meditation may not be suitable as an intervention to alleviate schizophrenic symptoms.

Secondly according to Champion and Power (1995, p.181) schizophrenia may be related to the relative over-activity of dopamine in certain tracts of neurons. Antipsychotics drugs, commonly used as treatment for acute schizophrenic episodes, work by blocking the effect that dopamine has on the brain (NHS, 2010). However, Rubia’s (2009) note that PET scans show that meditations of relaxed breathing exercise increased dopamine release in the limbic brain regions by 65%. This may not be beneficial for schizophrenic patients.

However a number of studies have provided evidence against this dopamine theory (Champion and Power, 1995) Furthermore, several 'slow release' antipsychotics are available whereby only one injection is taken every two to six weeks to control symptoms. This may be a more convenient and practical intervention compared with the long term, regular practice of meditation. There is a lack of studies which compare the effectiveness antipsychotics with meditation, and so it is too early to make any clear conclusions regarding meditation and schizophrenia.

The last finding implies the usefulness of meditation-based interventions in individuals with schizophrenia. According to McCarley (2004 cited in Bower, 2004) the absence of gamma activity in individuals with schizophrenia is related to dysfunctional neural circuits that cause some of the core symptoms the disorder. Rubia (2009) notes that as meditators achieve a state of ‘thoughtless awareness’, they show highly synchronised gamma activity in the frontal and parietal brain regions. This increase in gamma activity has been observed in experienced meditators (Lutz et al., 2004 cited in Rubia, 2009) and therefore have compelling implications for the prevention of schizophrenic disorders with meditation.

Summary
The inconsistencies in current literature and the lack of clinical studies demonstrate a need to test the effectiveness of meditation-based interventions in schizophrenic patients.

Effectiveness of Meditation on Personality Disorders
Similar to the findings of schizophrenia disorders, there have been no studies carried out on clinical patients with personality disorders participating in meditation-based interventions. The lack of empirical data means that definite conclusion cannot be drawn for the effectiveness of meditation in reducing symptoms of personality disorders.

However, tentative links can be drawn from the findings that may support the effectiveness of meditation to some extent (Mind, 2010) note that suffers of personality disorders are more likely to benefit from current treatment such as Group therapy, CBT and Dialectical behavior therapy (DBT), if they are able to think about and monitor thoughts, feelings and behaviour, accept responsibility for solving their problems, be open to change and have control over their emotions. These assets have been reported in several of the articles chosen for this review (Zylowska et al., 2008; Grossman et al., 2003; Rubia, 2009; Baer, 2003; Bishop, 2002; Krisanaprokornkit et al., 2006). For example, Baer (2003) report a significant increase in emotional stability as the patients’ problems is accepted non-judgementally.

And Rabai, (2009) who identify reduced gamma activity over frontal brain regions in response to the stressful stimuli which imply emotional stability. This suggests that meditation can be used as potential adjunct to current therapies as it may help patients to gain the most out of the therapy they are currently using.

Summary
Research is limited and empirical, well controlled and longitudinal study groups will be needed to establish any long term effects on personality disorders.
Findings those are relevant to all categories of psychiatric disorders.
Satisfaction of meditation-based intervention

Twelve out of the total twenty two studies chosen for review report positive satisfaction ratings towards the meditation technique they were taught. The Likert Scale or a self report reported questionnaire was used in most of the cases. In Baers’ (2003) review, 86% of psychiatric patients who had been engaged in some type of meditation intervention, reported that they “got something of lasting value” from the program. Miller et al. (1995), asked 18 participants with anxiety disorder to rate the importance of the MBSR program on a 1–10 scale (1 = no importance; 10 = very important). 89% gave ratings of 7 or higher. These high scores are predicted to lead to high adherence rate which is an important measure of success for any intervention (Dryden, 2005)

Practice
Authors and practitioners throughout the literature stress the importance of regular practice of meditation for its effect to take place.

It would be expected that the requirement of daily practice may be time consuming and unrealistic however it seems that the requirement has not posed a potential obstacle, infact it has been found that participants in the studies reviewed were motivated and willing to make a large time investment into their health.

In Shannhoff-Khalsa (2003) study, those who became free of OCD symptoms engaged in daily or near daily practice for the majority of the 12 months follow up, and most of them learned to do the ‘KY breathing technique’ full time. In another study, a patient noted that, the continuation of the practice led to a greater state of peace and general strength that has helped their OCD.

Shannhoff–Khalsa (2003) notes that the effectiveness of meditation may be affected by the patient’s ability to comply with the intervention, symptoms commitment to daily practice. All of these factors may vary from patient to patient and contribute to the success of the intervention. This will be looked at again later in section 7.3.

Limitations
In this section some general limitations will be discussed that apply to the reviewed articles.

Vulnerability to bias

The majority of participants were seeking help for their distressed symptoms and were recruited through advertisement. This may create a bias towards positive results, as studies test individuals who expect their symptoms to improve hence recorded progress may be attributed to the ‘expectancy effect’ rather than meditation.

The researcher might be trying to prove their hypothesis and as a result be bias in selecting instruments that may gear to workds a certain result. Only three out of the twenty two studies use blinded tests in their studies (out of which only one uses double blinded teats). The rest were aware of treatment condition and which may lead to the placebo effect.

Self reporting measures used

Self-report data has been used for many factors including, symptom reductions, perceived effects of meditation, recorded practice time and the satisfaction ratings of the meditation technique. Four studies usefully use brain scans to make the findings more objective and trustworthy. However the majority of articles fail to do so, and rely heavily on subjective measures. This reduces the validity of the relationship between meditation and effectiveness as a possible intervention for psychiatric disorder.
External Factors

There may be a lack of control over extraneous variables which limits the ability for current literature to produce statistically reliable data or attribute them to meditation per say. Two examples of possible factors that may have influenced these studies are as follows:

Teachers of meditation

None of the studies that were reviewed, took into consideration the capability and experience of the teacher of meditation. The teacher’s character, rapport, experience and qualification may have yielded different results. Further, the meditation instructor may not be a mental health professional with any previous experience working with mental disordered patients which poses limitation to examining the real effects of meditation (Koszycki et al. 2007).

Personality and Individual Differences

The current studies failed to broaden conclusions to represent a larger population. Individuals, who are likely to participate in meditation-based interventions, may have be haven an open personality to trying new things. In the real world, suffers of psychiatric disorders may be recommended to meditation-based interventions by their therapists or doctors. Therefore, patients may be more resistant to the effects of meditation or the requirement of practice as they have not volunteered themselves. The current literature has not tested different types of personalities and so the real resistance to treatment can only be predicted.

Concluding Remarks and Suggestions for Future Research
Notable findings of the effect of meditation-based interventions have been identified in the reviewed articles especially within the categories of anxiety and depression disorders. Further all studies which engaged in a follow up demonstrated the long term effectiveness of meditation on symptom reduction. This is despite the time demanded as patients were found to often engage in regular practice after the initial training had ended thus sustaining the positive effects and preventing the likelihood of relapse. In addition, high satisfaction rates and adherence to the intervention also makes meditation a plausible intervention.

However, it was also found that due to the significant research gap within schizophrenic disorders, cognitive disorders and personality disorders, conclusions may be limited. Due to the lack of studies only a handful of meditation techniques were evaluated for their benefits. This included mainly that of MBSR, MBCT and Kundalini Yoga, limiting the ability to conclude broadly on the effectiveness of meditation as a whole. It is yet to be explored as to which forms of meditation may be more effective in ameliorating different types of mental illnesses.

The use of Randomized Controlled Trials (RCT) would be suggested for future research which would produce more reliable, compelling and methodologically sound results. This will also allow meditation to be compared to alternative interventions including drug treatments and wait-list or treatment as usual. This may clarify whether observed effects are due to meditation training or confounding factors such as the ‘placebo effect’ or external variables.

Although it would seem that to operationalise and conceptualize meditation techniques, a clear comparison can be made, however there is a risk of overlooking the element of the ancient tradition from which meditation originates. As described by Kabat-Zinn (2000), the practice of mindfulness meditation is concerned with the cultivation of awareness, insight, wisdom, and compassion. These concepts may be appreciated and valued by many people but yet difficult to evaluate empirically. Perhaps future studies could acknowledge these aspects and instead improve on the ability of measuring the symptom reductions or changes. This may involve incorporating more Nero-imaging studies. PET and EEG scans can detect brain activity of psychiatric patients and provide an objective accompaniment to the subjective self report measures that are being used in the majority of studies reviewed.


In conclusion, there is significant evidence which suggests that meditation can be used as an effective intervention with long term implications and no side effects to psychiatric disorders particularly in anxiety and depression categories of psychiatric disorders. However there are significant gaps in evidence and research, particularly in the areas of schizophrenic disorder, personality disorders and cognitive disorder. Any further research in this area should ensure that cross sectional and controlled comparisons are taken into account. Additionally mediation interventions need to be complemented with existing psychotherapeutic and pharmacological interventions available and meditation has significant potential in alleviating suffering of those with psychiatric disorders in the world.