Global Health Asia-Pacific July 2020 July 2020 | Page 50

Cover Story
Antidepressants have a mixed track record when it comes to their efficacy
The efficacy of
antidepressants
is also
questioned
by pointing
to the limited
improvement
they offer
compared with
a placebo, or
dummy pill
abnormality, he said, several studies have shown that
the biology of depression is much more complex and
involves hormonal components as well as elements in
the structure of the brain.
The psychiatrist �oanna Moncrieff, however,
believes the evidence around the biology of
depression is not conclusive. She pointed out that
the chemical imbalance theory of depression is
unfounded because studies on brain chemicals like
serotonin are contradictory, showing that depressed
individuals can have lowered, similar, or even higher
levels than people who don’t experience depression,
while no clear abnormalities have been directly tied to
people with depression.
“Alongside biochemical theories, numerous
findings have been trumpeted as indicating the
disease-basis of depression, including variations in
cortisol (stress hormone), brain volume abnormalities
and neurotrophic factor. In all cases studies yield
inconsistent results, and none have been shown to be
specific to depression, let alone causal,� Dr Moncrieff,
Professor of Social and Critical Psychiatry at the
University College London, wrote in her blog.
“The fact that more than 50 years of intense
research efforts have failed to identify depression in
the brain may indicate that we simply lack the right
technology, or it may suggest we have been barking
up the wrong tree!”
The limitations of psychiatric drugs
The lack of clear-cut biological causes for
psychological distress suggests that a medical
approach is not necessarily the only way to deal with
distressful experiences. This idea is reinforced by the
mixed track record of psychiatric drugs in bringing
relief to mental sufferers.
There’s a heated debate over whether the longterm
use of antipsychotics is beneficial for patients.
While agreeing on their short-term usefulness
to control extreme forms of distress caused by
hallucinations and delusions, critics and supporters of
the medications can both point to studies that support
their own views on a given drug’s long-term efficacy.
In Weighing the evidence for harm from longterm
treatment with antipsychotic medications:
A systematic review, the authors concluded that
published data are “inadequate to conclusively
evaluate whether long-term medication treatment
results in better” or worse outcomes on average.
��ew data may be needed to establish a sufficient
evidence base to understand its benefit�risk balance
for patients with schizophrenia,” they wrote.
The efficacy of antidepressants is also questioned
by pointing to the limited improvement they offer
compared with a placebo, or dummy pill.
In 2002, Dr Irving Kirsch and his team sifted
through the evidence the FDA used to approve six of
the major antidepressants on the market and found
that only 43 percent of the trials showed a statistically
significant benefit of drug over placebo. However, on
average, those benefits were so dismal that they were
unlikely to be clinically significant for patients.
�urther observations on the similar benefits
offered by a wide range of antidepressants as well
as other types of drugs like tranquillisers and thyroid
medications reinforced the notion that those benefits
were mostly due to the placebo effect.
“It simply does not matter what is in the medication
� it might increase serotonin, decrease it, or have
no effect on serotonin at all. The effect on depression
is the same,” Dr Kirsch, Associate Director of the
Program in Placebo Studies at the Harvard Medical
School, wrote in the paper Antidepressants and the
�lacebo E�ect. �What do you call pills, the effects of
which are independent of their chemical composition?
I call them ‘placebos.’”
Dr First, however, contests the notion that placebos
work as well as antidepressants.
In the large studies testing the efficacy of
antidepressants, he said, many people experienced
small benefits, but some individuals saw very robust
improvements. “So, I think there’s no question
medications work in some people,” he said.
Other patients don’t respond to antidepressants
probably because they’re not getting the right
treatment for their problems. “A lot of disappointment
in the efficacy of medications has to do with the
mistaken idea that depression is just a chemical
imbalance while there are many psycho-social factors
in its development, and pills are not going to solve
those factors,” he added.
Though these factors often involve poverty, trauma,
and difficult life situations, there are lots of different
48 JULY 2020 GlobalHealthAndTravel.com