RLS Patients May Be at Risk for Pathologic Gambling

Pathologic gambling, an impulse control disorder, has been previously reported in patients receiving dopamine agonist therapy for Parkinson’s disease. Now, Mayo Clinic physicians have observed a small number of patients with restless legs syndrome (RLS) who have also developed pathologic gambling urges after treatment with do­pamine agonists. Their findings were reported in the January 23 Neurology.

Three RLS patients receiving do­pamine agonists developed strong gambling compulsions after about 9.3 months of treatment. Their gambling problems were noted during medical evaluations at the Mayo Clinic Sleep Disorders Center in Rochester, Minnesota. The patients were taking doses of about 0.45 mg/day of pramipexole or 0.25 mg/day of ropinirole at the time they began gambling or when their gambling became compulsive. The behavior worsened when dosages were increased. Two patients who had been recreational gamblers and had not previously lost large amounts of money developed compulsive gambling habits. A third patient began gambling while undergoing treatment for RLS.

One of the patients gambled away more than $140,000 before stopping treatment. “All patients described being preoccupied with gambling, using increasing amounts of money, [experiencing] irritability when unable to gamble, and being unable to control or stop the gambling behavior,” wrote the authors. “One patient reported getting caught in lies and deceptions to conceal his gambling and the financial consequences. Patients lost large amounts of money. No other compulsive behaviors were reported by [any] patient. Pathologic gambling resolved in all three patients on discontinuation of dopamine agonist therapy; however, two patients continue to gamble infrequently and without considerable financial losses.”

None of the RLS patients had signs of parkinsonism, and results of neurologic exams and MRI of the brain were normal. The gambling behaviors occurred at lower medication doses among the RLS patients than for the patients with Parkinson’s disease who were studied earlier. Patients with Parkinson’s disease developed gambling disorders at doses of 2 to 13.5 mg/day of pramipexole and 15 to 21 mg/day of ropinirole.

At least one of the patients in the study obtained relief from RLS symptoms with the use of gabapentin treatment (600 mg/twice a day), without any side effects.

In 2005, Mayo Clinic physicians discovered that 11 patients being treated for idiopathic Parkinson’s disease had developed pathologic gambling disorders. A study, led by Maryellen Dodd, MD, of the Mayo Clinic’s Department of Psychiatry and Psychology, found that pathologic gambling was a rare potential complication related to therapeutic doses of a do­pamine agonist.

Maja Tippmann-Peikert, MD, of the Mayo Clinic and lead author of the RLS study, said physicians should monitor Parkinson’s disease patients for this behavior, and RLS patients, who may be taking much lower doses of dopamine agonists.

Pathologic gambling may be cu­sed by an altered function, possibly  overstimulation of the dopaminergic reward system. Some researchers spec­ulate that newer drugs like pramipexole and ro­pin­irole are prompting the behavior.           

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