Listening to the breath, chanting a mantra, or detaching from the thinking process are all tools used in meditation to center the mind and bring about a state of self-awareness and inner peace. There are cultic and non-cultic varieties, the latter of which was produced for medicinal or scientific purposes. Meditation's calming and tension relief are believed to have prophylactic and preventive health effects, as a slew of scientific articles claim to demonstrate.
However, these studies have methodological flaws, that are discussed here, along with a brief review of the best evidence for meditation's
medicinal efficacy in clinical populations. Meditation does not have a Cochrane
review. Demonstrating that such physiological symptoms like a slower heart rate
or a specific electroencephalographic pattern exist during meditation and characterize
a "relaxed state" can provide insight into how meditation functions,
but it does not prove its therapeutic value. Most studies looking at the
long-term effects of meditation have had poor architecture.
When transcendental meditation, a common type of mantra
meditation, trials was conducted, they often compared self-selected meditators
with non-meditators or experienced meditators with novices. These studies did
not account for methodological variations in individuals who want to learn the
procedure and those who do not, as well as those who stick with it versus those
who stop. In randomized trials, positively predisposed participants are often
selected, resulting in assumptions of gain that vary from those of control
subjects. The favorable outcome of transcendental meditation trials for
cognitive benefits was limited to participants who were given passive controls
such as eyes closed rest.
Trials of naïve participants and plausible controls such as
pseudo meditation were found to be inconclusive. A previous meta-analysis of
cognitive behavioral therapies including meditation for hypertension found a
related connection. Many
co-interventions, heavy mortality, and insufficient mathematical interpretation
are among the other flaws. Recent clinical trials have been somewhat more
robust, but the number of participants has been reduced. Co-interventions such
as cognitive rehabilitation have been used in all controlled studies of
mindfulness meditation or disconnected perception of experience, but successful
controls have not been used, since outcomes cannot be removed or differentiated
from non-specific effects.
Few results in patients with poorly managed asthma were
changed by sahaja meditation or passive witnessing of thoughts, but the
differences did not last two months. People with epilepsy who practiced sahaja
meditation saw a substantial decrease in quantitative stress tests and seizure
frequency, but sufficient intergroup comparisons were lacking, and anxiety
levels and seizure frequency were significantly different between groups at
baseline.
Benson relaxation response, a non-cultic type of
transcendental meditation, had no significant effect on blood lipids, weight,
or blood pressure when added to a risk reduction program for elderly men with
hypercholesteraemia, and while patients with irritable bowel syndrome reported
a reduction in symptoms after six weeks of practicing Benson relaxation
response, the only significant difference was between the two groups.
Transcendental meditation has been widely researched, but most
of the research is still being done by scholars who are affiliated with the organization
that offers transcendental meditation and are eager to show its special
importance. The 35 trials of transcendental meditation were consistent with
slightly greater effect sizes than other approaches, according to a
meta-analysis of trials of calming and meditation for trait anxiety. However,
it involved unregulated experiments, and there is little evidence that the
result was unaffected by test design, type of supervision, or other
confounders.
The significance of healthcare populations remains
questionable since it omitted trials of people with mental disorders. As a
result, a revised and independent meta-analysis of anxiety-related mediation
research is desperately needed. The impact sizes of cognitive behavioral
strategies for hypertension is particularly sensitive to the methods used for
baseline measurements, according to a meta-analysis of studies.
Since then, a study using appropriate baseline tests has
shown that three months of transcendental meditation activity lowered
clinic-measured diastolic and systolic blood pressure compared to a group of
people who were granted schooling. The impact size of progressive muscle relaxation
was in the center. In the transcendental meditation community, the mean
modified increases in systolic and diastolic blood pressure were 10.7 mm Hg and
6.4 mm Hg, respectively.
This study, along with many others by scholars affiliated with the transcendental meditation association, suggest that meditation has a beneficial impact on blood pressure, a claim that should be objectively verified.
A study that found beneficial effects of transcendental meditation on
exercise tolerance in men with coronary artery disease was not randomized and
had significant baseline differences in exercise tolerance between groups that
surpassed the effect sizes recorded.
Co-intervention with food, exercise, herbal supplements, and
inadequate data collection due to attrition and lack of funds confound the
observed beneficial impact of transcendental meditation on the thickness of the
intima media of the carotid artery, an indicator of atherosclerosis.
A small study that found some benefit from transcendental therapy for asthma had significant issues with procedure adherence. The evidence for transcendental meditation's therapeutic efficacy in other conditions is either equally flawed or limited to small-scale studies.
Overall, the evidence for any form of meditation's therapeutic efficacy is poor, and evidence for any impact beyond that of reliable control measures is still weaker. The only protection concern seems to be in severely depressed patients, who may have psychotic episodes because of meditation. The limited research that does exist is in areas where stress reduction can have a significant positive impact, and potential studies with better design can have more definitive positive effects in this field.
