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| ECT patients must be assisted in breathing since the muscle relaxants given prior to the procedure tend to paralyze the lungs. |
A proper critique of ECT begins with a look at its scientific standing: Never mind the fact that its mode of action in not understood. Does it work? That's what this post talks about. In subsequent posts, we'll look at the question of whether ECT prevents suicide, and whether it actually harms people, not just in terms of short- and long-term cognitive effects but in terms of death.
We start by noting that modern evidence-based medicine relies on the use of placebo-controlled, double-blind studies. The literature on ECT goes back 75 years or more. But the overwehlming majority of studies conducted on ECT in that time have failed to include placebo groups. Most of the studies that claim a high response rate for ECT patients lack a control arm and thus do not conform to modern standards of evidence-based medicine. Also, "response rate" data are not long-term. They focus (almost always) on the treatment period itself, which last up to 30 days.
Until the 1950s, when general anesthesia
was introduced for ECT, it was not possible to include a control arm
in ECT studies, since there is no way to trick a fully-awake patient
into thinking he’s been shocked (and has had a grand mal seizure)
when he hasn’t. Only with the advent of anesthesia has it been
possible to use sham treatment consisting of anesthetizing the
patient and administering all other steps of the procedure except
for shock. (The sham-ECT patient is then told, when he or she wakes
up, that shock was applied, when it wasn’t.)
The sham ECT technique, as currently
implemented, can hardly be considered a faithful “placebo,”
however, since it fails to replicate other aspects of the bonafide
treatment, such as anterograde and retrograde amnesia, headache,
fatigue, and muscle ache. A valid comparison with ECT would require a
placebo that induces injury, which is obviously unethical. But
because sham ECT produces none of the typical cognitive or somatic
effects of “the real thing,” patients are very likely to guess
correctly whether they’ve been shocked or not. Hence, blind
breakage is a serious concern even in properly designed studies, and
can be expected to result in lower sham ECT response rates than might
otherwise be observed. It's worth bearing that in mind as we proceed.
Nine meta-analyses have compared ECT and
sham ECT for depression (Gabor & Laszlo, 2005; Greenhalgh et
al., 2005; Janicak et al., 1985: Kho et al., 2003;
Pagnin et al., 2004; Ross, 2006; Tharyan & Adams, 2005; UK
ECT Review Group, 2003; van der Wurff et al., 2003; see the complete list of references here). All except one
(Ross, 2006) make the claim that ECT is superior to sham ECT during
the treatment period (usually one month), but none found evidence
of any difference in outcome beyond the treatment period.
Claims
for the superiority of ECT versus placebo are based on effects seen
during the treatment period (one month); after the first
month, there are no differences between ECT and sham ECT groups. As
one author (Ross, 2006) said: “Claims in textbooks and review
articles that ECT is effective are not consistent with the published
data.”
Of the six studies considered by Janicak
et al. (1985), only two were said to have produced significant
differences between ECT and sham ECT. One was a crossover-design
study that gave ECT to the sham group during the treatment period,
confounding the results. Another was a very old study (Ulett et
al., 1956) in which ECT and “photoshock” results (from a
flashing-light technique, combined with hexazol) were conflated.
Janicak’s review was found by Ross (2006) to contain numerous
serious factual errors, calling into question its usefulness.
The UK ECT Review Group (2003)
meta-analysis reported that only one study met their inclusion
criteria for follow-up studies, and that study found no significant
difference. But the study in question had not, in fact, reported any
followup data.
The 170-page report by Greenhalgh et
al. (2005) concluded
“there is little evidence of the long-term efficacy of ECT” and
that, even in the short-term, “low-dose unilateral ECT is no more
effective than sham ECT.” The review found “no randomised
evidence of the effectiveness of ECT in specific subgroups, including
older people, children and adolescents, people with catatonia and
women with postpartum exacerbations of depression or schizophrenia.”
One of the nine meta-analyses mentioned
above, a Cochrane Systematic Review, focused specifically on the
effectiveness of ECT for the “depressed elderly” (van der Wurff
et al., 2003). This review found no evidence of ECT being
effective beyond the treatment period. It identified only one study
comparing ECT and sham ECT (O’Leary et al., 1994). The study
in question was a re-analysis of data from a paper by three of the
reviewers (Gregory et al., 1985), which the reviewers
described as having “major methodological shortcomings.” The
conclusion was that “None of the objectives of this review could be
adequately tested because of the lack of firm, randomised evidence.”
In addition to meta-analyses of ECT versus sham ECT for depression, there have been meta-analyses along these lines for schizophrenia.
A 2001 report by the American
Psychiatric Association admits that none of five pre-1980 ECT versus
sham ECT studies found any differences in outcomes, even in the short
term, but claimed that three more recent studies demonstrated “a
substantial advantage” for ECT (Abraham & Kulhara, 1987;
Brandon et al. 1985; Taylor & Fleminger, 1980). In all
three studies, however, both patient groups were receiving
antipsychotic medications, and any advantage for ECT was, in fact,
short-lived. In the Leicester ECT Trial (Brandon et al. 1985), for
example, both the ECT and the sham ECT groups improved on all four
measures used. “Global psychopathology” did not differ at all.
However, the authors note: “The superiority of real ECT was not
demonstrated at the 12- and 28-week follow-up.” Another of these
studies (Taylor & Fleminger, 1980) found that during treatment
there was equal improvement in both groups, although ECT improved
general psychopathology faster than sham ECT for the first four weeks
(only). In the Taylor & Fleminger (1980) study, the psychiatrists
(unblinded) were the only ones to perceive any difference in the
groups. Nurses and relatives did not see a difference. This might be
because psychiatrists are better trained to rate symptoms, but it is
also likely reflective of researcher bias, since most ECT studies are
done by researchers who strongly advocate the use of ECT and believe
in its benefits.
A more recent study (Sarita et al.,
1998) of 36 people diagnosed with schizophrenia found no differences
in double-blind ratings on four symptom measures after one, two,
three, or four weeks of treatment, in a comparison of sham ECT with
either bilateral or unilateral ECT.
A 2002 study (Ukpong et al.,
2002) likewise failed to find significant differences between ECT
and sham ECT at the end of treatment. It also failed to find
differences 20 weeks later.
A 2005 update of the Cochrane database
(Tharyan & Adams, 2005) found a short-term advantage for ECT over
sham ECT, but “no evidence that this early advantage for ECT is
maintained over the medium to long term.” The Cochrane reviewers
found that even in the short term, ECT was less effective than
antipsychotic medication.
More recently, Poublon & Haagh
(2011) published a systematic review of ECT for schizophrenia,
drawing only on randomized, controlled studies that included a sham
ECT arm. They found six such studies. In four of the six, ECT
produced statistically significant improvement relative to sham ECT,
during the treatment period, but in followup, no significant
differences remained. The authors said: “No evidence was found
proving the superiority of ECT over sham-ECT after followup.”
On the whole, ECT effectiveness is not
far different from sham ECT (and no different, after the
treatment period), raising the possibility that it is the anesthesia,
rather than the electrical shock, that produces much of the
therapeutic effect. Tending to confirm this possibility is the fact
that ketamine, a general anesthetic, has recently been found to be
therapeutic, on its own, for treatment of severe depression (McGirr
et al., 2014). If a study were to compare anesthetics used in
ECT with respect to the effect on depression outcomes, analysis of
variance might reveal the extent to which choice of anesthetic
influences outcomes, and this would tend to establish the degree to
which therapeutic effect is due strictly to anesthesia.
Unfortunately, no such studies have yet been done.
Colin A. Ross, M.D., of the Institute for Psychological Trauma in Richardson, Texas) has summed the situation up well in his 2006 paper:
Colin A. Ross, M.D., of the Institute for Psychological Trauma in Richardson, Texas) has summed the situation up well in his 2006 paper:
The author reviewed the placebo-controlled literature on electroconvulsive therapy (ECT) for depression. No study demonstrated a significant difference between real and placebo (sham) ECT at 1 month post-treatment. Many studies failed to find a difference between real and sham ECT even during the period of treatment. Claims in textbooks and review articles that ECT is effective are not consistent with the published data. A large, properly designed study of real versus sham ECT should be undertaken. In the absence of such a study, consent forms for ECT should include statements that there is no controlled evidence demonstrating any benefit from ECT at 1 month post-treatment. Consent forms should also state that real ECT is only marginally more effective than placebo.
Today's post is an excerpt from Hack Your Depression. Full references to the studies mentioned above are given in that book as well as here. Please buy a copy for anyone you know who may be suffering from depression. More information (including free excerpts from the book) can be found at HackYourDepression.com.
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