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 LACK OF EFFICACY
Most people are unaware of the fact that Zoloft and drugs like it are
not particularly effective in the treatment of depression or other “mental
disorders” for which they are approved and prescribed. Pfizer and the
other drug manufacturers do not want consumers to be aware of this fact.
The truth is, however, that in clinical trials, Zoloft often proved no
more effective than placebo (an inert substance like a sugar pill). That
is not to say the drug has no effect -- and thus, no side effects -- but
that it lacks effectiveness in treating the condition for which it is
prescribed (for instance, in depression).
A recently published study, which analyzed the clinical trials
submitted to the FDA to establish the drug’s efficacy, found that “the
pharmacological effects of antidepressants are clinically negligible.” The Emperor’s New Drugs: An Analysis of Antidepressant
Medication Data Submitted to the U.S. Food and Drug Administration by
Irving Kirsch (University of Connecticut), Thomas J. Moore (The George
Washington University School of Public Health and Health Services and Alan
Scoboria and Sarah S. Nicholls (University of Connecticut).
Kirsch et al. “analyzed the efficacy data submitted to the FDA for the
six most widely prescribed antidepressants approved between 1987 and 1999
[ ]: fluoxetine (Prozac), paroxetine (Paxil), sertraline (Zoloft),
venlafaxine (Effexor), nefazodone (Serzone), and citalopram (Celexa).”
(Id.) According to the authors: “Although antidepressant medication is
widely regarded as efficacious, a recent meta-analysis of published
clinical trials indicates that 75 percent of the response to
antidepressants is duplicated by placebo [Kirsch & Sapirstein, G.
(1998). Listening to Prozac but hearing placebo: A meta analysis of
antidepressant medication. Prevention & Treatment, 1, Article 0002a].
...”
In an article responding to commentaries on the Emperor’s New Drugs
study “Antidepressants and Placebos: Secrets, Revelations, and
Unanswered Questions,” Kirsch et al. stated that “there is now
unanimous agreement among commentators that the mean difference between
response to antidepressant drugs and response to inert placebo is very
small. It is so small that, despite sample sizes involving hundreds of
participants, 57% of the trials funded by the pharmaceutical industry
failed to show a significant difference between drug and placebo. Most of
these negative data were not published (see Thase, 2002) and were
accessible only by gaining access to U.S. Food and Drug Administration
(FDA) documents.” The authors go on to state:
The small difference between the drug response and the placebo response
has been a “dirty little secret” (Hollon, DeRubeis, Shelton, & Weiss,
2002), known to researchers who conduct clinical trials, FDA reviewers,
and a small group of critics who analyzed the published data and reached
conclusions similar to ours (e.g., Greenberg & Fisher, 1989). It was
not known to the general public, depressed patients, or even their
physicians.1 We are pleased that our effort facilitates dissemination of
this information.” (Id.)
_______________
FN 1. An internal memorandum by the Director of
the Division of Neuropharmacological Drug Products indicates FDA awareness
of this situation:
The Clinical Efficacy Trials subsection within the Clinical
Pharmacology section not only describes the clinical trials providing
evidence of citalopram’s antidepressant effects, but make mention of
adequate and well controlled clinical studies that failed to do so. I am
mindful, based on prior discussions of the issue, that the Office Director
is inclined toward the view that the provision of such information is of
no practical value to either the patient or prescriber. I disagree. I
believe it is useful for the prescriber, patient, and 3rd-party payer to
know, without having to gain access to official FDA review documents, that
citalopram’s antidepressants (sic) effects were not detected in every
controlled clinical trial intended to demonstrate those effects. I am
aware that clinical studies often fail to document the efficacy of
effective drugs, but I doubt that the public, or even the majority of the
medical community, is aware of this fact. I am persuaded that they not
only have a right to know but that they should know. Moreover, I believe
that labeling that selectively describes positive studies and excludes
mention of negative ones can be viewed as potentially “false and
misleading” (Lever, 1998, p.11).
_______________
* * *
The paper goes on to state:
“In the meantime, what are the alternatives for treating patients?
Imagine having a choice between four treatments. Treatment A produces a
large therapeutic response but also a large number of adverse effects,
including diarrhea, nausea, anorexia, sweating, forgetfulness, bleeding,
seizures, anxiety, mania, sleep disruption, and sexual dysfunction.
Treatments B and C produce therapeutic responses that are almost as great
as those produced by treatment A, but without the adverse effects. In
fact, the side effects produced by Treatment B are beneficial (e.g.,
better general physical health). However, the therapeutic effects of
Treatments B and C have been evaluated in relatively few studies.
Treatment D has been assessed in many comparative studies, in which it has
been found to be as effective as Treatment A in the short term and more
effective in the long term. It does not produce adverse effects. Given a
choice between these alternatives, which would you choose?
Of course, these alternatives are not merely hypothetical. Treatment A
corresponds to SSRIs, and the list of side effects is drawn from those
that have been shown to be produced by these medications (Antonuccio,
Danton, DeNelsky, Greenberg, & Gordon, 1999; Mulrow et al., 1999).
Treatment B is physical exercise, which has been reported to have lasting
therapeutic benefits in the treatment of major depression (Babyak et al.,
2000). It may be nothing more than a placebo, but if so, it is one with
desirable rather than adverse side effects. Treatment C is bibliotherapy
(e.g., Burns, 1999), another low-cost treatment with demonstrated
effectiveness (Jamison & Scogin, 1995; Smith, Floyd, Jamison, &
Scogin, 1997) and little danger of side effects. Treatment D is
psychotherapy. As noted by Antonuccio et al.(2002), “psychotherapy
(particularly cognitive therapy, behavioral activation, and interpersonal
therapy) compares favorably with medications in the short term, even when
the depression is severe (e.g., DeRubeis, Gelfand, Tang, & Simons,
1999), and appear superior to medications in long-term comparative studies
(Antonuccio et al. 1995; Hollon, Shelton, & Loosen, 1991)” ( 24).
Given these data, antidepressant medication might best be considered a
last resort, restricted to patients who refuse or fail to respond to other
treatments.”
In fact, in every independent study, exercise proved to be more
effective than Zoloft in decreasing depression. It should also be noted
that 15% of the paid volunteers in the clinical trials stopped taking the
drug because they could not tolerate the side effects
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