Summary: A new study examines how people with Parkinson’s disease — especially those who develop impulse control disorders (ICD) after taking dopaminergic medications — evaluate and emotionally respond to the outcomes of risky decisions. In a controlled experiment with 30 participants, researchers compared decision-making and emotional reactions between patients with ICD and those without, tested both on and off their dopaminergic drugs. The results indicate that patients with ICD show a reduced sensitivity to the consequences of risky choices and that medication amplifies the influence of expected outcomes on their feelings.
This research clarifies how dopaminergic treatments for Parkinson’s can alter risk perception and emotional processing, and it may offer insights into how addictive substances that affect dopamine signaling influence decision-making and reward-related feelings.
Key Facts:
- Dopaminergic Medications and ICD: Some people with Parkinson’s disease who take dopaminergic drugs develop impulse control disorders, which can lead to risky behaviors such as problematic gambling, compulsive shopping, hypersexuality, or binge eating.
- Differential Processing of Risk: Participants with ICD processed the outcomes of risky choices differently than those without ICD; they were less affected by whether a risky choice produced a good or bad result.
- Medication’s Role in Risk Perception: While on dopaminergic medication, patients with ICD showed stronger emotional responses that were driven by their expectations of reward, suggesting medications can heighten anticipatory feelings tied to risky decisions.
Source: Wake Forest University
Parkinson’s disease is a progressive neurological condition that primarily affects movement and muscle control. The disorder is associated with a loss of dopamine-producing neurons, and dopamine replacement therapies are commonly used to reduce motor symptoms. Although these medications can restore mobility and quality of life, they are also linked in some patients to behavioral side effects, including impulse control disorders.
Published online in Scientific Reports, the study was led by Kenneth Kishida, Ph.D., an associate professor of translational neuroscience and neurosurgery at Wake Forest University School of Medicine. The team set out to determine how decision-making variables—such as expected outcomes and actual results—affect subjective feelings after risky choices in Parkinson’s patients with and without ICD.
The researchers recruited 30 adults diagnosed with Parkinson’s disease: 18 had a clinical history of impulse control disorder and 12 did not. Each participant completed a computerized task twice—once while taking their usual dopaminergic medication and once after a period off medication. The task offered repeated trials in which participants chose between a guaranteed “sure bet” (a small, certain monetary amount) and a “gamble” that offered a 50-50 chance between two different monetary outcomes. After each choice and outcome, participants were intermittently asked to rate how they felt about the result. The research team then analyzed choices, reported feelings, and behavioral patterns using computational modeling.
Key findings reveal that people with ICD were less influenced by the actual outcomes of their risky choices: positive or negative results had a muted effect on their reported feelings compared with the non-ICD group. This diminished sensitivity to feedback occurred regardless of whether the participants were on medication. However, being on dopaminergic medication altered the balance between expectation and outcome for the ICD group—expectations of reward carried more weight in shaping their feelings when medicated than when off medication. This medication-related shift was not observed in participants without ICD.
Kishida and colleagues interpret these findings to suggest that for some patients with Parkinson’s disease, taking dopaminergic drugs may amplify anticipatory reward signals. Patients with ICD may therefore experience stronger positive feelings tied to the act of taking a risk, while simultaneously failing to register negative feedback in a typical way. Clinically, this combination could help explain why certain patients persist in risky behaviors despite poor outcomes.
Beyond Parkinson’s disease, the study offers broader implications for understanding how dopamine-modulating treatments and addictive substances could alter reward expectation, risk-taking, and subjective emotional responses. The research contributes to a growing literature on the behavioral and psychological side effects of dopaminergic therapy and highlights the importance of monitoring changes in decision-making and emotional processing in treated patients.
About this impulse control disorder and neuroscience research news
Author: Myra Wright
Source: Wake Forest University
Contact: Myra Wright – Wake Forest University
Image: The image is credited to Neuroscience News
Original Research: The findings will appear in Scientific Reports