Imaging
Antidepressant Accuracy - A simple one-hour brain scan could
predict who will respond to an antidepressant and who will not.
(11/14/02)
Cognitive
Behavioral Therapy - Psychologists are looking for ways other
than medication to help people make sense of and deal with the
voices they hear. A therapy adopted in Britain seems to have the
answer. (3/11/03)
Elsewhere on the web
The
Biological Basis of the Placebo Effect
Placebo
Response: All in the Mind
Parkinson's
Patients Feel the Placebo Effect
Skeptics
Dictionary on the Placebo Effect
Harnessing
the Placebo Effect
Why do some people get better with just lots of love, fresh air and a sugar
pill—at least for a while?
As this ScienCentral News video reports, neuroscientists say finding the answer
could help make real medicine more effective.
Power of the Placebo
It’s just a sugar pill. It has no active medicinal content, and yet
sometimes patients get well after taking it. In scientific communities it’s
known as a placebo. Its power has puzzled scientists and baffled pharmaceutical
industries for a long time. The improvements that patients experience from
taking placebos is known as the placebo effect.
Placebos are commonly used in clinical tests of new drugs. Andrew
Leuchter, professor of psychiatry at the University of California Los
Angeles’s Neuropsychiatry
Institute, says that when doctors test a new medical treatment or when
pharmaceutical companies develop a new medication, “they always end
up comparing it to a placebo, so they can see if this new medication that
they’re developing is better than no treatment.” The placebo effect
is so strong that new medications are generally not considered to be effective
unless they are proven to work better than placebos.
Although scientists are not sure about how the placebo works, recent studies
have illustrated that it’s power is hard to deny. Leucher and his colleagues
witnessed and studied the placebo effect in patients being treated for major
depression. In a study
published in the American
Journal of Psychiatry, the researchers explain that by using a technique
called quantitative electro encephalography or QEEG, they measured and studied
patient’s brain activity and showed for the first time that the placebo
effect is not just in the mind but that it’s a real change, a real “physical
phenomenon” in the brain.
Antidepressants vs. Placebos
The goal of their study was to find out how early they could detect changes
in brain function with antidepressant treatment. They assigned 51 patients
to either active medication or to placebos. The patients did not know which
group they were assigned to until after the study was completed. Then researchers
at the QEEG laboratory,
periodically measured patients’ brain activity.
“With antidepressants, if a patient was going to get better somewhere
down the road, we could see changes in brain function as early as 48 hours”
after treatment began, according to Leuchter. They saw a suppression of activity
in the prefrontal cortex of the brain, the area just behind the forehead.
The researchers also found, quite unexpectedly, that the patients who were
on the placebo showed a change in brain activity in the same area of the brain.
However, these patients showed an increase in brain activity and also the
changes came on much later, after about two weeks. “So,” Leuchter
points out, “it was a difference both in direction of change and the
time course of change”.
Positive Expectations
“The million dollar question,” Leuchter
says, “is why the placebo helps patients get better.” He thinks
the reason lies not in the pill but in the patients themselves. He explains,
“They go through the ritual of getting assessed, getting evaluated,
and then finally at the end of it all they get a capsule. It could be a white
pill or a blue pill. Whatever color it is, they have a strong expectation
built up that they are going to get help—that they are going to get
better. And we believe that both those things wrapped up together are what
count for the placebo effect.”
Leuchter warns that placebos cannot be substitutes for actual, bona fide medical
treatments. He says that even though some patients feel better on the placebo,
“it’s a short-lived response. It’s not nearly as robust.
It doesn’t have the staying power that medication has.”
But there are also very important lessons to be learned from the placebo effect.
Leuchter quotes an example of how the placebo effect can be harnessed to help
all patients get better on real medication. “So I’ve got an antidepressant
for the treatment of depression but I know [from studying the placebo effect]
that if a patient believes that that pill is going to help them then that
pill is going to be effective,” he says. So he says he may work with
the patient on their expectations, before he gives them the antidepressant,
and try to cultivate the positive expectation—the belief that the pill will
help them. This, he says, could make the anti-depressant more effective.
The study was funded by the National
Institute of Mental Health and the National
Alliance for Research on Schizophrenia and Depression.