Naltrexone for Impulse Control Disorders in Parkinson's Disease

Inclusion Criteria

• Diagnosis of possible or probable idiopathic Parkinson's disease (PD).
• Ages 18-85 years.
• Diagnosis of compulsive gambling, buying, sex behavior, or eating of >2 months duration.
• Impulse control disorder (ICD) behaviors that began after PD onset and in context of dopamine agonist (DA) treatment.
• Current stable DA use. Participants must be on a DA for 6 months and on a stable dose (no changes) for 1 month prior to enrolling the in the study.
• Subjects are capable of giving informed consent, supported by not having significant cognitive impairment based on Montreal Cognitive Assessment score ≥24.
• Willingness to maintain existing PD pharmacotherapy regimen for the duration of the study.

Exclusion Criteria

• Active suicide ideation.
• Anticipated need to initiate antidepressant therapy during the course of the study (must be on a dose in the therapeutic range for at least 2 months. If patient does end up needing to start antidepressant or change antidepressant dose during the course of the study, he/she will be allowed to continue study participation).
• ICD behaviors so severe that modification of DA treatment is clinically warranted, as judged by PI.
• Deep brain stimulation surgery in the past year.
• Evidence for significant liver disease by chart review or patient history (e.g., cirrhosis, chronic hepatitis, liver transplant, or liver cancer).
• Meeting diagnostic criteria for alcohol or opiate dependence.
• Meeting diagnostic criteria for Dopamine Dysregulation Syndrome.
• Use of opioids for pain management.
• Females that are pregnant, planning to become pregnant, or are breastfeeding will not be included in the study. Females of child bearing potential will need to verify that they are not pregnant by a negative urine pregnancy test.