Advance with MUSC Health

Parkinsons & Impulse Control Disorders

April 21, 2023
Mark Stacy, M.D.

There's a type of medication often prescribed to people with Parkinson's disease that can cause impulse control issues in some patients. In this episode, Mark Stacy, M.D., discusses this topic and how people impacted can be helped early and easily at the first signs of problems. Stacy is an MUSC Health neurologist with more than 30 years of experience in caring for patients with Parkinson's disease. He was one of the first doctors to report problems of impulse control disorders in some Parkinson's disease patients taking dopamine agonist medications.

“We now know that it's better to use these medicines in lower doses together than to push the dose higher in one, because if you push levodopa high, you get dyskinesias and if you push dopamine agonists high, some of the time you will develop these impulse control disorders. Two drugs with moderation is what I choose. ”
— Mark Stacy, M.D.

Topics covered in this show

  • About 1 million Americans are diagnosed with Parkinson’s disease. That number has increased recently due to an aging population.
  • Treatments for Parkinson’s disease involve trying to mimic dopamine in the brain. A medication called levodopa and dopamine agonists help with this, but dopamine agonists are associated with other behavioral problems.
  • Stacy first noticed impulse control disorders in his Parkinson's disease patients in 1999, when he had two patients report that they had lost a large sum of money gambling in casinos after Stacy had increased their dopamine agonist dosage. They experienced telescoping in their gambling addiction, where they lost smaller sums of money at first but then all of it in a shorter period of time. He also noticed patients responding to questions sent to them in the middle of the night right away, and found that nine patients of his who had all had an increase in their dopamine agonists displayed similar telescoping behavior.
  • About 20% of Parkinson’s disease patients develop impulse control disorders, including gambling, compulsive spending, hypersexuality, internet addiction or specific hobbies.
  • Stacy compares the prevalence of impulse control disorders in Parkinson’s disease patients to folks who are more susceptible to alcoholism than the average person. He posits that the large loss of dopaminergic neurons makes the dopamine’s effect on the remaining neurons more pronounced. He presented his findings at a scientific meeting in 2000 and is credited as the first to link the drugs to gambling in 2000.
  • Stacy discussed how a Parkinson’s disease diagnosis is difficult to give and receive, and that he reminds patients that it is a 30-year disease and walks them through the treatments and the possible side effects, including impulse control disorders. He prefers to administer low doses of two different drugs to treat Parkinson’s disease.
  • Stacy makes sure patients and their friends and family are aware of the potential issues with impulse control disorders, as the patients themselves may not notice the signs as quickly as their loved ones.
  • If there are symptoms and signs of impulse control disorders in patients taking the dopamine agonists, Stacy tries to take them off the drug completely, or bring them back to as low a dose as possible to avoid rare withdrawal symptoms.
  • More recently, doctors have turned to deep brain stimulation to treat Parkinson’s disease. MUSC Health has a program for this safe and well-tolerated procedure. Patients typically undergo this type of treatment when they cannot manage their motor symptoms to their satisfaction. It can completely erase the need for other medications.
  • MUSC Health has a wide array of treatment options for patients with Parkinson’s disease, and many programs and coordinators to help connect patients with the care they need.


Read the Show Transcript

Erin Spain, MS: [00:00:04] Welcome to Advance with MUSC Health. I'm your host, Erin Spain, MS. This show's mission is to help you find ways to preserve and optimize your health and get the care you need to live well. There's a type of medication often prescribed to people with Parkinson's disease that can cause impulse control issues in some patients. Mark Stacy, M.D. joins me with details on this topic. He is a MUSC Health neurologist with more than 30 years of experience in caring for patients with Parkinson's disease. He was one of the first doctors to report these problems of impulse control disorders in Parkinson's disease patients taking dopamine agonist medications. He's here to talk about how this can be managed early and easily at the first signs of problems. Welcome to the show.

Mark Stacy, M.D.: [00:00:51] Thank you. It's nice to be here.

Erin Spain, MS: [00:00:52] As the population ages, more and more Americans are being diagnosed with Parkinson's disease. How prevalent is this disease?

Mark Stacy, M.D.: [00:01:00] We think there's about a million people in the United States that have Parkinson's disease.

Erin Spain, MS: [00:01:04] And tell me about that. Is that number rising?

Mark Stacy, M.D.: [00:01:06] We've estimated a million for a long time, and I think in reality, it was probably 6 to 800,000 10 years ago. And we really are reaching a million now. And you're exactly right. It's because our population is aging.

Erin Spain, MS: [00:01:17] So what are the typical treatments right now offered to folks once they're diagnosed with Parkinson's disease?

Mark Stacy, M.D.: [00:01:23] Parkinson's disease is a disease that involves a group of nerves in the brain that make a neurotransmitter dopamine. And so the treatment of Parkinson's is to try to replace or mimic dopamine in the brain. There are several things that we do for that. Levodopa is the most commonly prescribed medication, and it turns into dopamine in the brain through a common reaction. The other medicines that we used in the past include these dopamine agonists. And dopamine agonists are nerves that bypass nerves that are damaged in Parkinson's disease and stimulate nerves that are left. But they're not exactly like dopamine. And that difference in their configuration and the way they stimulate can cause other behavioral problems that we didn't anticipate years ago.

Erin Spain, MS: [00:02:04] And one of those is these impulse control issues. As I mentioned, you were one of the first doctors to notice these issues in some of your Parkinson's patients. Take me back to that time. When did you first notice this and how did you connect with the dopamine agonists?

Mark Stacy, M.D.: [00:02:17] So I was practicing neurology at the Muhammad Ali Parkinson's Center in Phoenix in 1999 when a patient came in on a Tuesday and his wife said, Doctor, since he was last year, he's lost $60,000 in gaming casinos. And all I had done was change the dose of a medication, the dopamine agonist, and had increased it. Two days later, a patient came in and his wife said, Doctor, since he was last year, he's lost $60,000 in a gaming casino. So I'd also increased another dopamine agonist in that case. What we have found out and what we found out there is that casinos will allow you to lose $20,000 a month on a credit card and then they stop you. And so these two men used their credit card max each month. And what we found that was interesting was that the first month it took them several sessions, but the last month they lost it all in one session. And that's called telescoping. And it's a common thing in gambling addiction. So we went back and we're looking at a database at the time collecting information on patients, and we would send them several questions in the middle of the night and we would have people respond almost immediately and we thought it was kind of funny. But then we thought maybe this is telescoping. And so we went and looked at those people who were responding immediately, and we found seven other patients. All of them were patients of mine. And I had increased their dopamine agonist. Now I had increased it outside the normal range. But with those nine patients, we wrote a description and presented that at the International Movement Disorders meeting in 2000.

Erin Spain, MS: [00:03:46] And since that time, you and others have published several papers about this. It's now part of the literature, and people realize that about 14% of Parkinson's patients seem to be susceptible to impulse control disorders.

Mark Stacy, M.D.: [00:03:59] Yes. So about 14% are likely to develop symptoms of pathological gambling or compulsive gambling, compulsive spending, hypersexuality, Internet play where they are addicted to Internet, and then there's another group that develop hobbies. So there was a patient that was reported early on. He was an accountant and he would write down a string of numbers and then add them up in his head all day long. We reported a patient who would take apart radios and rebuild them all day long. A patient that would mow his lawn all day and then take apart his lawnmower and put it back together all night long. And so these behaviors can affect about 20% of the Parkinson's disease population.

Erin Spain, MS: [00:04:37] Tell me about these people. Are these folks that have a tendency to engage in these types of behaviors when they are not on this medication? Or what have you found out about who might be susceptible?

Mark Stacy, M.D.: [00:04:48] The population has the same array of behaviors. And I look at this as there are some people that can drink alcohol and never have a problem with it and never look at other substances. And there are some people in our population and we know them — they're in our families, they're our friends — who can't. And so I think it's the same thing with Parkinson's disease. The difference is in Parkinson's disease, you have about 20% of your dopaminergic neurons left. And dopamine acts on the same neurotransmitters as cocaine. So if you have 100% of your dopaminergic nerves there and you use cocaine, you have a change in your behavior and a difference in your feeling. Nobody would accuse dopamine as being as powerful as cocaine, but if you've lost 80% of your nerves, then perhaps dopamine is going to be that powerful. And so that's the analogy that I think about when these behaviors develop. 

Erin Spain, MS: [00:05:35] So how do you talk to your patients when they're first diagnosed and you're thinking about what medications to put them on? How do you approach this topic with them?

Mark Stacy, M.D.: [00:05:43] Parkinson's is a difficult diagnosis to give, but it's a much more difficult diagnosis to receive. When I talk to people about Parkinson's disease, I usually stop them and say, All right, I'm going to tell you something that's difficult. But after that, everything gets better. And then I tell them they have Parkinson's disease and we give it a minute and then I start talking about, really what does Parkinson's mean to me? And that it is not a five-year illness; it's a 30-year illness. And then I start talking about how we treat it. And I usually draw out a little diagram of the cell that's affected in Parkinson's and then the cell at second in the chain that we treat with dopamine. And I talk about presynaptic therapies, which would be levodopa and postsynaptic therapies which are dopamine agonist. Levodopa can cause nausea, it can cause low blood pressure, it can cause other symptoms, dopamine agonist can cause low blood pressure and these infrequent symptoms of impulsivity and impulse control disorders. And then we make a decision of what's best for them. The reason we avoid levodopa in young people is it can cause dyskinesias, which are involuntary movements, wiggly movements. And you've seen Michael J. Fox have these movements. That's what those are. I tell them there's no right or wrong in Parkinson's disease. We make a decision about whether we want to start levodopa or dopamine agonist today, but that most patients within five years of therapy are on both treatments. And we now know that it's better to use these medicines in lower doses together than to push the dose higher one, because if you push levodopa high, you get dyskinesias and if you push dopamine agonists high, some of the time you will develop these impulse control disorders. Two drugs with moderation is what I choose. 

Erin Spain, MS: [00:07:14] So now with this better dosing information, do you still see a lot of these impulse control disorders come up in your clinic?

Mark Stacy, M.D.: [00:07:21] Never as bad as that first year. And it still astounds me that we never really saw these behaviors until the late 1990s. And I think it reflects our increased addiction to devices and immediate feedback and how it changes our brains. But when I first reported this, it was met with a lot of resistance. So come on, that's not true. And people made fun of it. And it was a difficult time for patients. There are patients who have lost hundreds of thousands of dollars by buying things. If you happen to be a day trader, you could really lose money. And there was initially some resistance in the courts. There was a settlement and changes in drug labels for Parkinson's disease and talks about pathological gambling, other behaviors. You may see that on commercials for medicines for depression now, and they can develop the same things. So this previously unknown behavior is now so prevalent in society that you see commercials about it with other drugs so people know about it. We watch it much more closely and we keep our patients informed and really our patients, partners and family informed because they are the ones that really have to watch this, because often those two men that I talked about at the beginning of the segment, they didn't know they were losing money like that and were horribly embarrassed.

Erin Spain, MS: [00:08:34] So if there are symptoms and signs, which it sounds like there's not as many cases these days with dosing, but what do you do? Or do you take the person off of the drug totally or just keep reducing the dose?

Mark Stacy, M.D.: [00:08:46] We try to take them off the dose totally. There is a very rare condition that we've seen since all this described called dopamine agonist withdrawal syndrome. And some patients have severe difficulties coming off these drugs. That's a very sad situation because every time we reduce the dose, their anxiety levels go up. And it's not just in anxiety like we have if we're watching our children play a softball game or something like that, it is almost paralyzing anxiety. And so we have to dance very closely along that line and monitor them for disruptive behaviors and try to get them on as little dose as possible so they don't have this panic all the time.

Erin Spain, MS: [00:09:23] Tell me about the field and how things have progressed in the past even 10 years as far as treatments, both treatments that are invasive or medical and other treatments out there now.

Mark Stacy, M.D.: [00:09:34] The biggest advance we've had in treating Parkinson's disease is using deep brain stimulation and placing electrodes in the brain. We have a wonderful center for deep brain stimulation here. I started one in Phoenix, I started one at Duke. This one's better. And we have phenomenal results because we have neurologists and neurosurgeons and their team that do just this. And so if we see a patient having dyskinesias or having these behaviors, the best long term approach would be to move to deep brain stimulation. When it started it was associated with a lot of worry about side effects and bleeding in the brain and things like that. But this new generation of neurologists and neurosurgeons who work together in the O.R., these untoward and difficult side effects are extremely rare. And so it's a safe and well-tolerated procedure, and it's a very big program here.

Erin Spain, MS: [00:10:21] At what point in the progression of the disease would someone undergo that deep brain stimulation procedure?

Mark Stacy, M.D.: [00:10:27] When we no longer manage their motor symptoms to their satisfaction. So the levodopa lasts about four hours; It peaks at about two hours, and it can leave your system where it's not effective. After about three at the peak, you have these wiggly dyskinesias that Michael J. Fox has and then it wears off. There comes a time where you cannot take medicine every three hours, eight times a day. And so that's an indication that we want to move toward deep brain stimulation. And the other is if you're having these impulse control behaviors, we can take you off of those medicines completely, usually with DBS.

Erin Spain, MS: [00:10:58] And tell me about typical results of this procedure.

Mark Stacy, M.D.: [00:11:02] I laughed with neurosurgeons to say I spend hours and hours making these patients as good as we can, and within three hours you make them better than I ever could. And it really does produce a major benefit in quality of life.

Erin Spain, MS: [00:11:14] I can imagine this is very difficult on families and partners as well, not only dealing with this experience, but then also being able to really verbalize what they're seeing, because sometimes these disorders, these symptoms can be difficult to spot. Can you tell me about that?

Mark Stacy, M.D.: [00:11:31] They are difficult to spot. It's helpful to sometimes see a kind of a change in their behavior where their patients are not themselves and they kind of look like they're thinking about something else all the time. And so you can say, OK, that looks like somebody is not talking to me. They're obsessed and thinking about something else. But that's a pretty soft sign. We ask about this every time patients are in, just like we ask about dyskinesias for levodopa. And so asking about it is also helpful. The public is pretty well informed now to this, and so we don't see it nearly as much.

Erin Spain, MS: [00:12:00] Folks listening as we just mentioned, the population is aging. This is the second most common neurological disorder right now that's diagnosed in Americans. What would you say to patients, caregivers, family, friends who know somebody or themselves who's been given this diagnosis? What are some words you'd like to share with them about what's offered at MUSC Health and what their prognosis can be?

Mark Stacy, M.D.: [00:12:23] Number one is Parkinson's is a 30-year illness. It is not a five-year illness. You don't have to start making plans that are different from retirement, plans that you started thinking about when you didn't know what a 401k was. The second thing is there are a wide array of treatment options short of surgery that are available throughout the state. But we have specialists here who spend all their time looking at these options, really like taking care of people with Parkinson's disease. And you will get correct information and we will spend our time with you so you don't get a walk down the hall and you've got Parkinson's disease sort of approach. We spend 30 minutes with you, an hour when we first start to see you and more if we need to. We also have a number of programs and coordinators who will be in contact with you about education opportunities and other treatment opportunities that are different from medication. There's a boxing program that is very good for Parkinson's disease, and we have worked very closely with the leaders of that program. So I think we have options that may not be available to you and locally we can get those options to you with a coordinator from here so you don't have to come here for therapy and things like that. We teach people all over the state how to work with people with Parkinson's.

Erin Spain, MS: [00:13:33] The last question we ask everyone that comes on the podcast is what do you do to optimize your health and live well?

Mark Stacy, M.D.: [00:13:39] That's a question that sometimes I answer better than others. In life, you learn how to take care of yourself better and better, and as you age when you don't, it lasts longer. I have a life partner lucky enough to know, and since 1980s we enjoy each other's company and that's probably the most sustaining thing that I have. But we also take care of each other and we make sure that we eat right and we get a little exercise along the way and we try to enjoy our lives when we can. We have a new grandson and we've found a way to really enjoy our life a whole lot better. And I think that will keep us in shape so we can watch him graduate from high school and college and those sort of things.

Erin Spain, MS: [00:14:17] Thank you so much, Dr. Mark Stacy, for coming on the show and explaining this rare but important condition that can affect some people on Parkinson's disease medications. Thank you so much. [00:14:27][9.8] 

Mark Stacy, M.D.: [00:14:27] Thank you.

Erin Spain, MS: [00:14:32] For more information on this podcast, check out