The study involved 100 people with RLS who were seen at the Center for Sleep Medicine at Mayo Clinic. All of them were being treated or had been treated with “dopaminergic” drugs.
These drugs stimulate the dopamine receptors in the brain. Dopamine is a chemical that acts as a neurotransmitter. It is believed that RLS may involve a dysfunction in the brain’s dopamine system.
The study group completed questionnaires about impulse control disorders. Phone interviews also were conducted.
They were compared with two control groups. One group consisted of 52 people with RLS who had never been treated with a dopaminergic drug. The other group had 275 people with obstructive sleep apnea who did not have RLS.
Results show that impulse control disorders occurred in 17 percent of people with RLS who were treated with dopaminergic drugs. They occurred in eight percent of the RLS control group and six percent of the OSA control group.
Nine percent of the RLS treatment group reported compulsive shopping. Five percent reported pathologic gambling.
Seven percent reported “punding.” This involves purposeless, repetitive actions. Examples include sorting objects and excessive grooming or cleaning.
These rates were significantly higher than in people with OSA. The rate of compulsive shopping was higher than in the RLS control group.
People being treated for RLS were most likely to have impulse control disorders while taking pramipexole (Mirapex). Some RLS patients also struggled with impulse control while taking ropinirole (Requip).
Eight people stopped taking a medication due to an impulse control disorder. Within several weeks the problem ended or improved in all of them.
The authors noted that dopamine plays a role in the brain’s “reward system.” In some people dopaminergic drugs may overstimulate brain areas involved in this system.
They added that doctors treating people with RLS should monitor them for symptoms of an impulse control disorder. These disorders can have devastating effects.
In May 2008 the FDA approved the first generic versions of ropinirole for RLS. Learn more about RLS.
Image by Kevin Labianco