Cognitive Correlates of Decision-Making in Parkinson's Disease: A Systematic Review

Abstract

Introduction: Changes in decision-making (DM) are frequently observed in patients with Parkinson's disease (PD). Despite extensive research, the relationships between DM and various cognitive functions remain incompletely understood. This systematic review aims to synthesize existing evidence on the link between DM and cognition in PD, emphasizing a comprehensive perspective that considers multiple cognitive domains and various DM tasks. Methods: A systematic literature search was conducted across PubMed, PubPsych, and LIVIVO databases. Inclusion criteria encompassed studies that examined the relationship between DM performance and cognitive functions in individuals with PD. Data extraction focused on sample characteristics, types of DM tasks employed, cognitive domains assessed, and key findings on their association. Results: A total of 38 studies, published between 2001 and 2025, involving 1,313 individuals with PD, were identified. Most of these studies used laboratory-based DM tasks – with the Iowa Gambling Task (IGT) as the most frequently used DM paradigm, followed by the Game of Dice Task (GDT) – whereas only few studies employed ecologically valid DM tasks that simulate real-life DM contexts. A substantial number of studies investigated the association of DM performance with global cognitive status, executive functions, and memory. Fewer studies explored social cognition, psychomotor speed and attention, visuo-construction and visuo-spatial skills, language, and numerical abilities. Most analyses on the association between DM and cognition in PD revealed non-significant findings. Among the studies reporting significant associations, findings did not consistently cluster around specific cognitive domains or DM tasks, indicating heterogeneity in results. Conclusions: This systematic review highlights the complex and often inconsistent relationship between cognitive functions and DM in individuals with PD. Despite some evidence of significant associations, most findings are non-significant, scattered, and influenced by methodological variability across studies. Future research should aim for standardized, ecologically valid assessments and consider the multifaceted nature of cognition and DM to better elucidate these relationships in PD.