Compulsive gambling with extreme
losses -- in two cases, greater than $100,000 -- by
people without a prior history of gambling problems has
been linked to a class of drugs commonly used to treat
the neurological disorder restless legs syndrome (RLS).
A new Mayo Clinic study is the first to describe this
compulsive gambling in RLS patients who are being treated
with medications that stimulate dopamine receptors in
the brain. The Mayo Clinic report appeared in the Jan.
23 issue of Neurology.
The extent of this problem is unknown. Apparently, it
occurs only in a small number of RLS patients treated
with drugs called dopamine agonists. Considering this
potential side effect of dopamine agonists, the Mayo Clinic
authors suggest that physicians screen all RLS patients
for compulsive behaviors while taking a thorough medical
history prior to prescribing dopamine agonists. Patients
should be monitored closely for signs of compulsive behaviors
once dopamine agonist treatment has begun. The report
suggests that the compulsion to gamble worsened with increasing
doses of the dopamine agonists.
Current Report Builds on Earlier Findings
Pathological gambling is an impulse control disorder.
In 2005, Mayo Clinic physicians reported this disorder
as a side effect of dopamine agonist therapy in 11 Parkinson
disease patients. "Although pathologic gambling has
already been recognized in patients with Parkinson disease
who often took high doses of dopamine agonists, the current
report suggests that pathological gambling is not restricted
to patients with Parkinson disease -- and also can occur
at low dosages" explains Maja Tippmann-Peikert, M.D.,
the lead author of the Mayo Clinic report on restless
legs syndrome. "Physicians should not only monitor
Parkinson disease patients for this behavior but also
screen their RLS patients who may be on much lower doses
of dopamine agonists." This includes encouraging
the patient, family members and friends to report negative
behaviors to the patient's physician.
Fortunately, pathological gambling seems to be reversible
when the dose of the dopamine agonist is reduced or the
patient is transitioned to an alternative medication.
It is crucial that these adjustments are initiated before
significant gambling debts develop, and relationships
and careers are damaged.
Significance of the Mayo Clinic Report
This preliminary Mayo Clinic report is the first to link
pathologic gambling to use of dopamine agonists in a disease
other than Parkinson. It is based on the experience of
three patients who have RLS. Their gambling problems were
discovered during their medical evaluations at the Mayo
Clinic Sleep Disorders Center. Although three patients
is a small sample and larger studies are needed to validate
these observations, the Mayo Clinic authors believe that
the possible link between dopamine agonists and pathologic
gambling behavior should be brought to physicians' attention
immediately due to the social and financial consequences
resulting from the behavior.
The Mayo Clinic neurologists found that gambling problems
began, on average, about nine months after the patients
began taking one of two dopamine agonists, pramipexole
or ropinirole. Speculation is that the gambling problems
are emerging now because the newer generation of dopamine
agonists -- including pramipexole and ropinirole -- are
targeting receptors located in brain structures involved
in motivation, emotion and reward behaviors. Researchers
theorize that, in some people, such strong and specific
stimulation in these neuronal pathways can prompt compulsive,
pleasure-seeking behaviors such as pathological gambling.
One patient, a woman seen in the Mayo Clinic Sleep Disorders
Center, had a five-year history of regular nighttime creeping-crawling
sensations in her legs, accompanied by the strong urge
to move her legs. Two and a half years prior to her Mayo
Clinic visit, she had been diagnosed with RLS and treatment
with pramipexole was begun.
Her symptoms improved, however, a problematic behavior
developed soon after she started taking the medication.
She developed an uncontrollable urge to gamble when visiting
the nearby casino. As the dose increased, her gambling
compulsion grew stronger. The transition of her therapy
to another dopamine agonist, ropinirole, further increased
her compulsion to gamble. Prior to her treatment for RLS,
she had no history of gambling and viewed gamblers as
"unfortunate individuals," the authors report.
The patient lost more than $140,000 from gambling.
Mayo Clinic physicians discontinued the dopamine agonist
therapy and her urge to gamble completely disappeared,
but the troublesome leg sensations returned. Her RLS is
now successfully treated with a non-dopamine agonist,
gabapentin, and she has no side effects, according to