Accidental Blogger

A recent study published in pLOS suggests that the so-called efficacy of antidepressants may be in large part due to a placebo effect, which would imply that the same level of effective treatment could be achieved by offering placebos to the mild to moderately depressed patients who currently form a huge chunk of the lucrative market for Prozac, Paxil, Effexor etc.

Placebo effects hinge on the assumption that what is being received is an ‘active’ pill, as shown in the results of this UCLA comparison of Prozac with a placebo group:

To find the answers, the UCLA study involved 51 individuals with major depression, each of whom was enrolled in one of two separate, nine-week controlled studies. Overall, 52 percent (13 of 25) of the subjects receiving antidepressants — either fluoxetine, commonly known as Prozac, or venlafaxine, known as Effexor — responded to treatment, while 38 percent (10 of 26) of those receiving placebos responded, the study states.
…
After eight weeks of blind testing, when the subjects were told either that they had been given a placebo or medication, the research team noted a dramatic change. "The individuals taking a placebo lost all of the improvement they had made and had a recurrence of their symptoms," Leuchter said. "We believe it is reasonable to suppose that a belief in treatment is an important component of the placebo response. The expectation of getting better contributed greatly to improvement."

The pharmaceutical industry has been quick to defend their turf:

But
in a statement, American Psychiatric Association President-elect Nada
Stotland, MD, maintained that studies like those reviewed by Kirsch and
colleagues, which compare a single drug to placebo, do not accurately
reflect the way doctors prescribe antidepressants.

"We know that many people who are depressed do not respond to the
first antidepressant they try," she says. "It can take up to an average
of three different antidepressants until we find the one that works for
a particular individual. Therefore, testing any single antidepressant
on a group of depressed individuals will show that many of them do not
improve."

The question nevertheless arises then, if
simply switching between various antidepressants is part of trying to
find out what works for a patient, why not institute switching to a
placebo as part of the regimen? But that would be messing with the cozy
relationship between physician and drug company.

Even there, sneaky measures may be needed to persuade the patient of the efficacy of the placebo. As noted in this Alternet article:

A
critical scientific standard in drug studies is the double-blind
control (neither subject nor experimenter knows who is getting the drug
and who is getting the placebo), but drug-company antidepressant
studies use blinds that can be peeked through. How? Inactive placebos
such as sugar pills, which don’t create side effects, are used, and so
subjects can more easily guess if they are getting the actual drug. In
order to make it more difficult to penetrate the blind, an active
placebo, which creates side effects, should be used. In 2000, a
Psychiatric Times article concluded: "In fact, when antidepressants are
compared with active placebos, there appear to be no differences in
clinical effectiveness."

While the debate continues, fostered by the gigabucks at stake in
definitively deciding the issue of pill vs. placebo, ‘new and improved’
medications continue to be added to the market: 

Pristiq is a derivative of Wyeth’s widely used Effexor
depression drug and the company had hoped it would be approved
long before Effexor loses its U.S. patent protection in 2010
and faces generic competition.

  …
 

"It could wind up with sales of $500 million to $1 billion
because so many patients switch between depression drugs" to
obtain relief, and Pristiq will be one of the relatively few
available options, Tong said.

Wyeth in December said a low-dose 50-milligram form of
Pristiq was effective in two late-stage depression trials and
far better tolerated than a 100-milligram version that failed
to win U.S. approval in early 2007.
 

…

In studies of the 100-milligram dose of Pristiq conducted
more than a year ago, a high percentage of patients complained
of nausea and stopped taking the drug, creating doubts that
doctors would prescribe it or patients take it even if it were
approved.
 

Wyeth scrapped that formulation and began studies of the
now-approved 50-milligram pill, hoping it would not cause
nausea. The percentage of patients who dropped out of the
trials because of side effects was similar to those who
received a placebo, indicating the lower dosage pill was
tolerated.

‘Similar to those who received a placebo‘- so was it the placebo
effect being used in reverse to imply the efficacy of the lower dosage
of Pristiq that even double the dosage did not achieve?

Anything to keep the cash cow alive for another day, I guess!