New research suggests that some patients with anorexia or
bulimia who receive targeted, non-invasive magnetic brain stimulation may
experience relief from their binge eating and purging behaviours.
Doctors used a procedure called "repetitive
transcranial magnetic stimulation" on 20 patients with entrenched cases of
anorexia or bulimia. The treatment prompted measurable symptom improvement
among half of those in the group, and the finding raises hopes for an
alternative way to battle tough-to-treat eating disorders.
"The upshot is that between 50 and 60% of the time
you're getting at least a 50% reduction in bingeing behaviour," said study
author Dr Jonathan Downar, a clinician scientist in the department of
psychiatry at the University Health Network in Toronto.
"And this is
among patients who had already tried everything for their eating disorder, and
nothing had worked. So, what we're talking about is completely
Downar was to present his team's findings Tuesday at the
Society for Neuroscience annual meeting, in San Diego. Research presented at
medical meetings should be viewed as preliminary until published in a
About 8 million North Americans suffer from chronic eating
disorders such as bulimia and anorexia, the researchers noted. While
prescription drugs and behavioural therapy help some people, they do not help
The notion that brain stimulation might work for these
patients came about almost by accident, Downar said, after the treatment helped
patients who struggled with depression.
It was a 2011 case study in particular that pointed the
way, after a patient diagnosed with both depression and bulimia experienced
almost complete relief from both conditions after just two weeks of brain
In this latest study, 20 patients suffering from anorexia
or bulimia received 45-minute sessions of brain stimulation, given 20 times
over a four- to six-week period (at a cost of roughly $6,000). The stimulation
was directed toward the region of the brain considered critical in the
execution of self-control with respect to thoughts, emotions and behaviour.
The result: enhanced activity in the targeted regions
resulted in a 50% drop in binge eating and purging behaviours among nearly half
the patients; another third saw their problems dip by at least 80%, and in some
cases the behaviours disappeared altogether.
Brain scans indicated that those who responded to the
treatment may have distinctly different brain-activity patterns than those who
"Those who did well with [brain stimulation] showed a
lack of connection of physiological circuitry between the part of the brain
that is supposed to tamp down on urges and cravings and the regulation
area," Downar noted. "So stimulating that area repeatedly helped make
the missing connection," he explained.
"But nonresponders seemed to actually have more
connections to the regulatory circuitry than average. So [brain stimulation]
did nothing for them because a need for more stimulation is not their
problem," he added.
"But we think that maybe if we change the stimulation
target for these patients, and change it to inhibit rather than excite
stimulation, we might ultimately be able to help even these patients,"
Downar suggested. "We think it's possible."
Dr Doug Klamp, a specialist in eating disorders with a
private practice in Scranton, Pasadena., said the approach "seems
"Bulimia can be a very difficult problem," Klamp
explained. "When patients come to me, 60 to 70% will be cured within a
year or so. But those other 30 to 40% are tough.
Safety of new technique
They can try all the
standard antidepressants and antipsychotic medications, and all the behavioural
therapy options, but their problem behaviour may still go on. For
decades," he added.
"So, a new therapy would be very helpful," Klamp
said. "And this idea makes sense to me, because I tend to see the same
impulsive and destructive behavioural characteristics over and over again in my
patients, as if it's hard-wired into people – hard-wiring that maybe, with
this, we can change."
Suzanne Mazzeo, a professor of psychology at Virginia
Commonwealth University in Richmond, cautioned that it's still unclear why
brain stimulation seems to help some but not all patients.
"Certainly, we do need more approaches. Eating disorders
are very difficult problems to treat because our food environment is stacked
against us, with food manufactured to be highly palatable and hard to
resist," Mazzeo pointed out.
"So, overcoming any kind of emotional eating issue is
going to be hard," she added. "And what we currently have for
treatment is certainly not working for everyone."
But, Mazzeo noted, "in addition to ensuring the safety
of this new technique and testing it for long-term maintenance, we have to be
sure why it works for some and not others, so we can know who would be the most
appropriate candidates for it."
For more on eating disorders, visit the US
National Library of Medicine.