Parkinson's Disease, Impulsive-Compulsive Behaviors, and Health-Related Quality of Life.

OBJECTIVE: A large body of literature has examined the links between the use of dopamine replacement therapy (DRT) in Parkinson's disease (PD) and the development of "impulsive-compulsive behaviors (ICBs)." Little is known regarding the link between the development of ICBs and health-related quality of life (HRQOL). We aimed to explore the factors that are associated with poorer HRQOL, especially in relation to DRT-induced ICBs, in a sample of PD patients. METHODS: This PARKADD (PARK: PARKinson's disease; ADD: behavioral ADDictions) study was a prospective case‒control study initially designed to assess the factors associated with ICBs in PD patients. A prospective clinical follow-up was added, aiming to capture the long-term evolution of HRQOL in relation to ICBs occurring or worsening after the beginning of PD. We focused on sociodemographic and PD characteristics and the history or presence of ICBs. HRQOL was measured using the Parkinson's Disease Questionnaire-8. A multivariate linear regression was performed to identify factors related to poorer HRQOL. RESULTS: A total of 169 patients were eligible for the follow-up study. The presence of an ICB, a higher levodopa equivalent daily dose (LEDD) and a longer PD duration were significantly associated with poorer HRQOL, with an interaction between LEDD and PD duration. CONCLUSION: The presence of an ICB was related to poorer HRQOL and should be considered a crucial factor for the management of PD patients. Several studies were recently published that provide guidelines for the management of these patients, with recommendations based on two key principles: prevention and specific treatment.

Parkinson's disease and iatrogenic impulsive-compulsive behaviors: A case/non-case study to build a complete model of individual vulnerability.

Background and aims: Parkinson's disease (PD) is one of the most prevalent neurodegenerative diseases. First-line medications consist of drugs that act by counteracting dopamine deficiency in the basal ganglia. Unfortunately, iatrogenic impulsive-compulsive behaviors (ICBs) can occur in up to 20% of PD patients over the course of their illness. ICBs must be considered multifactorial disorders that reflect the interactions of the medication with an individual's vulnerability and the underlying neurobiology of PD. We aimed to explore the predictive genetic, psychopathological and neurological factors involved in the development of ICBs in PD patients by building a complete model of individual vulnerability. Methods: The PARKADD study was a case/non-case study. A total of 225 patients were enrolled ("ICB" group, N = 75; "no ICB" group, N = 150), and 163 agreed to provide saliva samples for genetic analysis. Sociodemographic, neurological and psychiatric characteristics were assessed, and genotyping for the characterization of polymorphisms related to dopaminergic and opioid systems was performed. Results: Factors associated with "ICBs" were younger age of PD onset, personal history of ICB prior to PD onset and higher scores on the urgency and sensation seeking facets of impulsivity. No gene variant was significantly associated, but the association with the opioid receptor mu 1 (OPRM1) rs1799971 polymorphism was close to significance. Discussion and conclusions: The influence of gene-environment interactions probably exists, and additional studies are needed to decipher the possible role of the opioid system in the development of ICBs in PD patients.

Naltrexone Use in Treating Hypersexuality Induced by Dopamine Replacement Therapy: Impact of OPRM1 A/G Polymorphism on Its Effectiveness.

Hypersexuality is a well-known adverse side effect of dopamine replacement therapy (DRT), and anti-craving drugs could be an effective therapeutic option. Our aim was to update the knowledge on this issue, particularly on the influence of an Opioid Receptor Mu 1 (OPRM1) genetic polymorphism. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We also analyzed a case of iatrogenic hypersexuality that occurred in a patient treated with DRT. An analysis of the OPRM1 gene was performed on said patient. Our search identified 597 publications, of which only 7 were included in the final data synthesis. All seven publications involved naltrexone use. Five of them were case reports. None of the publications mentioned DRT side effects, nor did they report genetic data. Regarding our case report, the introduction of naltrexone corresponded with the resolution of the patient's hypersexuality. Moreover, the patient carried the A/G genotype, which has been reported to be associated with a stronger response to naltrexone for patients with an alcohol use disorder. Although studies are inconclusive so far, naltrexone could be an interesting therapeutic option for resistant hypersexuality due to DRT. Carrying the A/G genotype could help explain a good response to treatment.