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Like Drugs, Talk Therapy Can Change Brain
Chemistry
by Richard A. Friedman, M.D., New York Times, August 27,
2002
For more articles on disabilities and special ed visit
www.bridges4kids.org.
After six years of twice-weekly psychotherapy sessions, Eric
had plenty of insight. But his anxiety level had barely
changed.
He was still bedeviled by a ceaseless urge to wash his hands
and shameful and repetitive violent thoughts. Out of
desperation and against the wishes of his therapist, he
visited my office to discuss the possibility of medication.
"I thought I could understand my way out of my obsessive
compulsive disorder," he recalled recently. "I wanted to be
able to do it on my own, without medication."
What he did not remember was his vehement opposition to
psychotropic medication on the ground that it was not natural
and would change his brain chemistry.
Of course, he was right. Like Eric, many patients and
therapists share the view that psychotherapy is preferable to
pharmacotherapy because it is more "natural" and because it
supposedly gets to the root of the patient's problem. They are
convinced that self-understanding will bring relief, whether
the problem is anxiety, depression or obsessional thinking.
Insight is a prerequisite of happiness, the theory goes, and
well-being achieved without the hard work of psychotherapy is
artificial and inauthentic.
But new evidence suggests that the talking cure and
psychotropic medication have much more in common than had been
thought. In fact, both produce surprisingly similar changes in
the brain.
Take Eric's obsessive compulsive disorder. It hobbles patients
with unwanted thoughts, often violent or sexual, that play in
the mind like a broken record. Owing to the sometimes lurid
nature of the thoughts, the treatment mainstay had for years
been psychoanalytically oriented therapy to unlock the sexual
and aggressive conflicts presumed to underlie the symptoms.
There was just one problem. That form of psychotherapy rarely,
if ever, worked for those patients, a point now widely
accepted by most psychoanalysts themselves.
But two seemingly different treatments can be highly
effective: a form of talk therapy called cognitive-behavior
therapy and a class of antidepressants called selective
serotonin reuptake inhibitor antidepressants, or S.S.R.I.'s,
drugs like Prozac and Zoloft. It is well known that patients
with the disorder have altered serotonin function compared
with normal controls.
Brain imaging that uses PET scans, or positron emission
topography, has shown that the disorder is associated with
functional hyperactivity of the caudate nucleus, a structure
buried beneath the cerebral cortex. Some researchers
hypothesize that the caudate is part of a subcortical circuit
that acts as a kind of filter, sifting out extraneous thoughts
and impulses.
In obsessive compulsive disorder, they theorize, the
subcortical filter malfunctions, allowing the unwanted
thoughts to reach the cortex and then on to consciousness.
In a study by Dr. Lewis Baxter at the U.C.L.A. School of
Medicine, patients with the disorder who responded to either a
reuptake inhibitor like Prozac or cognitive behavior therapy
over 10 weeks showed virtually the same changes in their
brains, decreases in the activities of the caudate nuclei and,
thus, changes toward normal function.
When patients improved, the changes in their brains, as shown
in the PET scans, looked the same regardless of whether they
had received antidepressants or psychotherapy.
An S.S.R.I. works, in part, by enhancing the neurotransmitter
serotonin, whose activity is often abnormal in people with
obsessive compulsive disorder and depression. Cognitive
behavior therapy focuses on changing distorted patterns of
thinking.
The intriguing finding from the PET scans is not limited to
O.C.D. Two studies of patients with depression, reported last
year in The Archives of General Psychiatry, compared the
effects of interpersonal psychotherapy with an antidepressant
on brain function, as observed in PET scans. In those studies,
the depressed patients received interpersonal therapy, a
short-term talk treatment that focuses on the effects of
social relationships and major life events on mood.
In one study, a 12-week trial that compared an S.S.R.I., Paxil,
to interpersonal psychotherapy, Dr. Arthur Brody, also at
U.C.L.A., found that depressed patients who responded to
either treatment had nearly identical changes in their brain
function, a decrease in the abnormally high activity seen in
the prefrontal cortex before treatment.
In the second study, Dr. Stephen D. Martin at the research
unit of Cherry Knowle Hospital in Sunderland, England,
reported that six weeks of Effexor, an antidepressant that
enhances both serotonin and norepinephrine, and interpersonal
therapy produced similar effects in those depressed subjects
who responded either to medicine or to psychotherapy. Each had
shown an increase in the activity of the basal ganglia, a
subcortical brain structure.
Although the observed changes with psychotherapy and
antidepressant were similar in that study, they were not
identical. Subjects with interpersonal therapy but not Effexor
also had activation of a brain area called the cingulate gyrus,
which responds to serotonin in the brain and has a role in
regulating mood.
The studies show that pharmacotherapy and psychotherapy can
produce remarkably similar effects on functional brain
activity. But does that mean that antidepressants and
psychotherapy are really equivalent?
In a word, no. Psychotherapy alone has so far been largely
ineffective for diseases like schizophrenia, where there is
strong evidence of structural, as well as functional, brain
abnormalities. So it seems that if the brain is severely
disordered, then talk therapy cannot alter it.
But it is clear that talk therapy can alter brain function.
The reason may come from the elegant work of a Nobel
Prize-winning psychiatrist and neurobiologist, Dr. Eric Kandel.
Studying the simple and well-mapped nervous system of a sea
slug, Aplysia, Dr. Kandel showed that learning leads to the
production of new proteins and, in turn, to the remodeling of
neurons.
Sea slugs exposed to the controlled-learning condition that
produced long-term memory ended up with double the number of
neuronal connections as the untrained animals. In essence, Dr.
Kandel has proved that learning involves the creation of new
neuronal connections.
The clear implication for humans is that learning literally
changes the structure and function of the brain.
Now it may seem a big leap from a snail to a human. But if
psychotherapy is thought of as a form of learning, then when
therapists talk to patients, they cause them to learn, perhaps
changing their brain function and, perhaps, for the long run.
In the end, Eric chose cognitive behavior therapy and improved
drastically. Through exposure to those situations that he
feared like messy dirty places, he became desensitized to them
and lost his compulsion to wash.
Had he chosen an antidepressant, chances are that he would
also have improved.
If psychotherapy produces nearly the same brain changes as
pharmacotherapy, then the boundary between mind and brain is
purely artificial — even unnatural.
The author is a psychiatrist who directs the
Psychopharmacology Clinic at the New York Weill Cornell
Medical Center.
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