A new take on placebos

December 29, 2010

It has long been known in medicine that placebos can be surprisingly
effective, for the treatment of a wide range of disorders.  A placebo, whose name is taken from
the Latin for “I please,” is an inert substance, a sugar pill, that
should have little to no effect on any physiological process.

A “placebo-controlled study” is considered the gold standard in medication
trials; in such a study, half of the patients with a given condition
are prescribed an active medication, while the other half are
prescribed a placebo.  In virtually all studies, there is some
improvement in the placebo group, and this improvement can, at times,
be significant.  In trials of antidepressants, for example, it has
been estimated that up to 75% of the antidepressant response may be due
to a placebo effect, an observation that has received much
popular press of late.

A research group at Harvard Medical School has taken this one step
further.  They took a group of patients with irritable bowel
syndrome (IBS), gave half of them a placebo, and the other half nothing.  (This would be, I
guess, “placebo-placebo controlled study”!)  More importantly,
however, they even told the
placebo group that they were getting a placebo!  Specifically,
they told patients that they would get “placebo pills made of an inert
substance, like sugar pills, that have been shown … to produce
significant improvement in IBS-symptoms.”

In their report (available freely here), they
showed that the placebo was more effective at treating IBS symptoms
than nothing at all, and– even though they did not directly compare
placebo to any active medication– they found that the rate of
improvement was twice the success rate of the most powerful IBS
medications.

While this raises several important questions about the utility of
placebos in medicine, it also hits at the heart of a lot of what we do
in psychiatry.  Most psychiatrists have the experience of seeing a
patient fail multiple medications but exhibit a positive response to
yet another medication from the same class, for no obvious
reason.  Or giving two similar patients the same medication and
finding that one responds while the other does not.

Modern biological psychiatry looks at situations like these and asks,
what are the interindividual biochemical or physiological differences
that predict response to one agent over another?  Are there
genetic or other biological markers that make one person a better
candidate for medication X than for medication Y?

This study, however, raises new questions in situations such as
these.  If patients’ symptoms can improve after taking an inert
substance (and I’d be interested to see a repeat study on patients with
a mental illness– although IBS itself is a “psychosomatic” illness
with strong psychological features), this result cannot be ignored and
ascribed to chance.  Something is
working in this treament, but exactly what?  Is it the way we talk to patients about
treatment?  Something about patients’ expectations of treatment?  If
patients don’t believe that their meds will work, does this prompt them
to enact more effective behavioral changes in their lives?  It
appears that patients have more of an ability to solve their problems
than we often give them credit for, and this study should prompt us to
look for those strengths, not serve as ammunition to attack the
weaknesses of psychiatric medicine.

2 Comments | Uncategorized | Permalink
Posted by stevebMD

Are we more depressed?

December 21, 2010

A new study in the Archives of General Psychiatry examines trends in the treatment of depression between 1998 and 2007, and finds that—surprise, surprise!—we’re treating more depression.

The study finds that the rate of outpatient treatment for depression increased from 2.37 per 100 persons in 1998 to 2.88 per 100 persons in 2007.  That is, almost three of every 100 persons reported that they sought some sort of treatment for depression.

Some other findings from the study:

1998 2007
Percentage of depressed patients on antidepressants 73.8% 75.3%
Percentage of depressed patients who received psychotherapy 54% 43%
National expenditures for outpatient treatment of depression $10.05 B $12.45 B
Cost attributed to medications $4.59 B $6.60 B

(1998 numbers adjusted for inflation)

So what does this all mean?  Well, for starters, here’s how the study was done:  about 23,000 individuals were interviewed about their treatment over the past year.  If patients reported seeking help for “depression,” they were included, even though they may have been suffering from dysthymia, a depressed phase of bipolar disorder, an adjustment disorder, or an underlying anxiety or substance use problem.  Regarding the expenditures, these numbers were gathered from large databases of office visits and hospitalizations, and data were included only if the providers gave a diagnosis of major depression, dysthymia, or “depression not otherwise specified.”

Note the rise in medication costs, up to $6.6 billion in 2007.  (Of this, the proportion borne by Medicare rose from $0.5 to $2.25 billion, most likely due to the implementation of Medicare Part D in 2006.)  These numbers reflect a substantial increase in how much money we’re paying for antidepressants and other medications to treat depresssion.  (In case you were wondering, the total outlay for the entire Medicare program in 2007 was $375 billion.)

So we’re spending more money on depression treatment, and more than half of that money is on medications for depression.  (Incidentally, the same researchers also reported that the percentage of all Americans taking antidepressants in any given year rose from 5% to 10% over the same time period.)  Does that mean we’re winning the war on depression?  Doesn’t look like it.  Does it mean people are more depressed now than they were in the past?  Possibly.  Is there some other reason why patients are seeking help, and providers just find it more palatable to give a diagnosis of depression?  That’s a possibility, too.

All I can say is, when I see numbers rising like this—whether we’re talking about disease rates, costs, or numbers of prescriptions—it means we’re not handling this epidemic very well.  The question is, epidemic of what, exactly?

2 Comments | diagnostics, mental health | Permalink
Posted by stevebMD

The future of psychiatric diagnosis?

December 20, 2010

What is a mental illness?  To most psychiatrists, the answer lies in the DSM-IV, essentially a catalog of diagnoses and diagnostic features of each disorder.  It has been derided as presenting a “cookbook” (or, perhaps less PC, a “Chinese menu”) approach to psychiatry, in which a diagnosis is made on the basis of the presence of a number of symptoms drawn from a list.

While this approach has proven helpful for research and clinical purposes, it unfortunately oversimplifies what is undoubtedly an extraordinarily rich spectrum of mental disorders.  (It also, of course, calls into question where is the demarcation between “normal” and “disorder” on that spectrum, but more about that some other time.)  As any clinician will tell you, no two depressed patients are alike, just as no two schizophrenics are alike, no two bipolar patients are alike, and so forth.

In reality, there may be dozens of diseases that we now call “scihzophrenia” (or “depression” or “panic disorder,” etc).  Some may stem from a clear genetic mutation in some as-yet unidentified gene, while others may be a consequence of endocrine dysregulation or disturbances in brain development.  Others may be defined by their propensity to respond (or not) to various pharmaceutical agents, or the patient’s biological tendency to endure side effects of such agents such as weight gain or movement disorders.

The National Institute of Mental health (NIMH) is trying to expand our nosologic system by incorporating neurobiolgoical and physiological measures as well as observable behavior in our classification of psychiatric disorders.  The Research Domain Criteria aims to

… define basic dimensions of functioning (such as fear circuitry or working memory) … across multiple levels of analysis, from genes to neural circuits to behaviors, cutting across disorders as traditionally defined.

What might this mean for the future of psychiatry?  For starters, instead of a checklist to generate a diagnosis, a clinician might order a brain scan, a blood test, a measure of some genetic marker, or a more intensive review of one’s history in order to develop an “individualized” treatment approach.  How long it takes to get to this point (and whether we can afford it) remains to be seen.

2 Comments | diagnostics | Permalink
Posted by stevebMD

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