ENDO 2019 Preview: Constant Craving: Linking Addiction and Endocrinology

A variety of cases will be presented at ENDO 2019 that will demonstrate how certain endocrine treatments can cause or worsen addictive behaviors. Ashley Grossman, MD, FRCP, discusses how with a little bit of detective work, endocrinologists can understand the underlying circumstances that cause these erratic actions.

Ashley Grossman, MD, FRCP, of Oxford University in the United Kingdom, was involved in the care of a patient many years ago who suddenly began behaving strangely in his personal life. This patient started having affairs. He spent money well beyond his means, making strange and ill-advised investments, and throwing lavish parties. He bought multiple Rolls Royces.

Eventually this patient’s wife left him because of his erratic behavior. He ended up destitute. But all of his out-of-character actions and their subsequent consequences were the result of an endocrine disorder – or more accurately, a treatment for an endocrine disorder.

“His whole life was ruined because he was taking these drugs, and nobody specifically connected his chaotic lifestyle. Maybe he didn’t even tell them about it,” Grossman says. “He just came in and said, ‘Oh, I’m feeling fine. Everything is good.’”

Most endocrinologists, when asked what made them want to go into this particular specialty, will say that they like how endocrinology ties into so many other things, and they enjoy following the clues, solving the puzzle – true detectives. One of the highlights of ENDO 2019 in New Orleans is a symposium on Tuesday, March 26 titled “Neuroendocrine Aspects of Addictive Disorders.” This session will touch on a number of topics, from food addiction to the opioid epidemic – as well as the lessons learned from cases like Grossman’s patient: that even endocrine treatments can play a role in developing compulsive and dangerous behaviors.

Scheduled to share the lectern with Grossman are Nicola Abate, MD, University of Texas Medical Branch Galveston; Gavin Bart, MD, PhD, Hennepin Healthcare, Minneapolis, Minn.; and Anthony P. Goldstone, PhD, Imperial College London, UK. The goal of the session is to educate practicing clinicians so that they can better recognize patients who might be affected.

Side Effects

Millions of people in the U.S. and the United Kingdom have some sort of addiction, and many of those people will engage in compulsive behaviors while on drugs or alcohol, or they will engage in destructive behaviors to obtain more drugs or alcohol. But this is a different story.

“And it’s only when you maybe talk to [a patient’s] family that you find out that they are spending tens of thousands of dollars on gambling debts or they’re buying lots and lots of brand-new cars.” – Ashley Grossman, MD, FRCP, Oxford University, Oxford, United Kingdom

Grossman and his team analyzed data from patients who are being treated for prolactinomas, for which they take dopamine agonists, drugs which have been known to cause impulse control disorders in patients being treated at higher doses for Parkinson’s disease. Dopamine agonists are a primary treatment of prolactinomas because these drugs have been shown to be effective – even at lower doses — at shrinking these tumors. “They have very widespread use, and the most common drugs are bromocriptine and cabergoline,” Grossman says. “These same drugs are also used at much higher doses in patients with Parkinson’s disease. In patients with Parkinson’s, it was known that at least 10%, maybe up to 50% of all patients [get] impulse control disorders, and that’s defined as having a very strong impulse or motivation to do something which you know is harmful for yourself or other people. And that’s because it activates a subclass of dopamine receptor which causes these behavioral problems.”

Impulse control disorders are an adverse side effect of dopamine agonists, and impulse control disorders carry with them a number of documented co-morbidities, including depression and anxiety, problems sleeping, and even development of substance or gambling addictions. And while impulse control disorders are seen more in younger patients who are being treated for Parkinson’s disease, Grossman says endocrinologists are seeing them more frequently in people being treated for prolactinomas, even small ones, who are taking much lower doses than patients with Parkinson’s.

Family Matters

In a 2018 article published in Drug Safety by Grall-Bronnec, et al., titled “Dopamine Agonists and Impulse Control Disorders: A Complex Association,” the authors write: “A substantial amount of literature is consecrated to the examination of the links between the use of [dopamine agonists] in [Parkinson’s disease] and the development of [impulse control disorders], and this topic continues to be a very active field of research. In most cases, emphasis is placed on iatrogenic factors. Furthermore, the same association in [restless leg syndrome] or prolactinoma is rarely addressed, and, to the best of our knowledge, there is no review available that takes into account the three diseases for which [dopamine agonists] are prescribed.” Of course, the review goes on to do just that, but the study of impulse control disorders in patients taking dopamine agonists for prolactinoma is still a relatively new arena.

And what’s more is the fact that impulse controls disorders aren’t easily manifested, according to Grossman. “People don’t realize they’re connected,” he says, “and the main types of impulse control are compulsive gambling, compulsive sexuality, compulsive shopping, and all sorts of compulsive and sometimes repetitive behaviors which can be very damaging to the individual and their family.”

“My talk is really just to increase awareness. It can occur in men or women. It’s maybe more common in men. It can occur at any age and often at any dose.” – Ashley Grossman, MD, FRCP, Oxford University, Oxford, United Kingdom

When a patient comes into an endocrinologist’s office, the conversation is usually about how they feel, questions about hormone level tests. But even patients who have developed impulse control disorders may tell their endocrinologist that they feel just fine. “And it’s only when you maybe talk to their family that you find out that they are spending tens of thousands of dollars on gambling debts or they’re buying lots and lots of brand-new cars,” Grossman says.

Making the Connection

In the conclusion to the paper by Grall-Bronnec, et al., the authors write, “The prevalence of [impulse control disorders] ranged from 2.6 to 34.8% in [Parkinson’s disease] patients, and from 7.1 to 11.4% in [restless leg syndrome] patients. There are insufficient data available on prolactinoma to draw a conclusion with respect to prevalence.”

Grossman’s talk at ENDO this month in New Orleans is aimed at raising the specter of the rare but real possibility that patients being treated for prolactinomas with dopamine agonists will develop impulse control disorders. The patient who lost everything because of his impulse control disorder might have been spared that fate. But again, endocrinologists might not be aware that there is a connection, or the patient may not think about it, or even could be aware there’s a problem but too embarrassed to bring up their gambling problems or outrageous spending habits.

“My talk is really just to increase awareness,” Grossman says. “It can occur in men or women. It’s maybe more common in men. It can occur at any age and often at any dose.”

-Bagley is the senior editor of Endocrine News. He wrote the cover story on artificial intelligence in the February issue.