 Bioelectromagnetic
Medicine – Chapter 44 Unabridged Version
Cranial Electrotherapy Stimulation for Anxiety, Depression, Insomnia,
Cognitive Dysfunction, and Pain: A Review and Meta-Analyses
Daniel L. Kirsch, Ph.D., D.A.A.P.M., F.A.I.S. and Ray B. Smith, Ph.D.
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Accordingly, CES stimulates regions of the brain
responsible for pain messages, neurotransmitter genesis, and the
hypothalamic-pituitary axis which controls hormone production and
control throughout much of the body. If one assumes that such
stimulation, even at the microampere level, is sufficient over time to
generate activity in each of those areas of the brain, then one has
cause to suspect symptom reduction in a multiplicity of areas of the
body.
This chapter will focus on the scientific clinical studies of CES and
will report primarily on the three treatment claims for CES presently
permitted by the FDA: anxiety, depression and insomnia. We will then
report on promising emerging clinical uses of CES that have been
scientifically demonstrated, as published in the peer-reviewed
scientific literature.
II. Summaries of the Scientific Studies A.
Depression
Many studies of depression have appeared in the American literature.
While some studies found a remission of depression serendipitously
while researching other symptoms (11), others, while researching
depression specifically, did so with varying protocols which ranged
from open clinical designs with no controls (12), to single blind with
sham treated controls (13), to double blind with placebo controls.
(14)
Measuring strategies have also ranged widely from clinical estimates
of no known reliability or validity (15) to measurement with
standardized tests of known reliability and validity. (16)
While the typical study reported significant changes at the 0.05 or
0.01 level or above, some reported the percent of patients showing
clinical improvement of various degrees instead. (12) More recently,
in the era of competing pharmaceuticals in medical treatment, American
medicine has become less interested in statistically significant
results and more interested in comparative effectiveness and safety of
one treatment as opposed to another.
Two problems have developed from that interest; the term “significant”
still often refers to the confidence limits of 0.05 or 0.01 found when
comparing the mean differences between treated and control subjects,
but in pharmaceutical studies it now often refers also to the number
of patients improving at a level of 25% or more above their initial
score, which is also termed “significant improvement.” On the other
hand, while the number or percent of patients in a study experiencing
sometimes very difficult negative side effects are usually published
in the report, that number is not factored into the “significant”
findings of the study, regardless of which of the two meanings is
intended. The reader of such studies is left on his own to determine
what the outcome means in his overall appreciation of the clinical
importance, in terms of safety and effectiveness, of any new
treatment.
CES studies have been guilty of the “significance” trap also, in that
most have reported out only the significance of the confidence limits
of the mean changes among patients in the studies, and have not
concentrated on the actual amount of change effected by CES treatment.
That is known as the “effect size” and will certainly become more
commonly reported in future scientific studies, where “percent
improvement” is now reported at best. The two terms are statistically
synonymous. For now, effect size is the basic unit reported in the
increasing number of meta-analytic studies appearing in the literature
in which a reviewer statistically combines a large number of studies,
the outcomes of which can vary widely, to learn what improvement a new
group of patients should experience from a given treatment on average,
and what the upper and lower limits of the mean of that expected
outcome would ordinarily be 95% (or 99%) of the time when the
treatment is applied. Those numbers are reported in meta-analyses as
the effect size, usually including the standard error of the mean
effect size obtained from the studies included in a given
meta-analysis. That is, giving a new group of patients a range within
which the expected effect size might reasonably be seen to vary.
What can a practitioner expect for his depressed patients when he
recommends CES treatment after more than 30 years of CES studies and
clinical application in the U.S.A.? Tables 1 and 2 give a
meta-analytical summary of 25 studies of depression over the past 32
years dating from 1970 through 2002. |
