Scientific American
March 8, 2013
In response to my last post, which proposed that Transcendental
Meditation and other cults might be exploiting the placebo effect, some
readers cited studies supposedly showing that TM has therapeutic benefits.
Well, sure. There are lots of studies showing that lots of forms of meditation
can yield lots of benefits. But the research is unimpressive, to say the least,
and is corrupted by the “allegiance
effect,” the tendency of proponents of a treatment to find evidence that it
works. (The term was coined by a Lester Luborsky, a prominent psychotherapy
researcher.)
For a critical overview of meditation research, see a 2000
article in the Journal of Consciousness Studies, “Meditation Meets Behavioral
Medicine,” which I discussed in my 2003 book Rational Mysticism.
Author Jensine Andresen, now a religious scholar at Columbia, reviewed more
than 500 papers and books on meditation published over the last half century.
Andresen cautioned that there are thousands of techniques that could be
categorized as meditation; it is virtually impossible to define the term in a
way that does justice to this vast diversity.
Not surprisingly, she said, attempts to measure
meditation’s neurological effects with brain-wave monitors, positron emission
tomography, and other techniques have yielded widely divergent findings.
Meditation has been “prodded and poked by a variety of technological apparati,
with inconclusive results,” Andresen commented. For every report of increased
activity in the frontal cortex or decreased activity in the amygdala, there is
a conflicting finding.
Investigations of meditation’s therapeutic benefits have
been equally inconclusive. Meditation has been linked to a dizzying array of
benefits, including the alleviation of stress, anxiety, high blood pressure,
substance abuse, hostility, pain, depression, asthma, premenstrual syndrome,
infertility, insomnia, substance abuse and the side effects of chemotherapy.
But many of these studies have been poorly designed, Andresen remarked, carried
out with inadequate controls or no controls at all.
Andresen noted that meditation has been linked to adverse
side effects, too, including suggestibility, neuroticism, depression, suicidal
impulses, insomnia, nightmares, anxiety, psychosis and dysphoria. In an
implicit reference to the cultish context within which meditation is often
taught, Andresen added that meditators may become vulnerable to “manipulation
and control by others,” including “unscrupulous or delusional teachers.”
A similar picture emerges from the 2007 peer-reviewed
report “Meditation
practices for health: state of the research,” by the National Center for
Complementary and Alternative Medicine. The report analyzed 813 studies of
meditation and concluded that most were of “poor quality.”
The report stated: “Many uncertainties surround the
practice of meditation. Scientific research on meditation practices does not
appear to have a common theoretical perspective and is characterized by poor
methodological quality. Firm conclusions on the effects of meditation practices
in healthcare cannot be drawn based on the available evidence.” If your
particular form of meditation makes you feel good, do it! But don’t kid
yourself that its medical benefits have been scientifically proven.
