This study shows that negative global metacognitive bias—driven by depression and anxiety—underlies subjective cognitive complaints in prodromal PD and PD without objective impairment.

While not revealing molecular targets, this identifies modifiable affective contributors and measurement considerations that could inform symptomatic treatments, patient selection, and outcome measures in PD trials.

OBJECTIVE: Subjective cognitive decline is common in persons with Parkinson's disease (PwPD) and prodromal PD (proPD) and predicts objective cognitive decline. Subjective concerns may reflect enhanced sensitivity to cognitive changes or negative global metacognitive biases (general underconfidence, not task specific) related to depression or anxiety. We evaluated the presence and predictors of metacognitive awareness, the self-assessment of one's cognitive abilities, in PwPD and proPD. METHOD: Data from 468 PwPD, 817 proPD, and 75 healthy control adults were drawn from the Parkinson's Progressive Markers Initiative database. Measures included subjective- and objective-cognitive composites. We assessed metacognitive sensitivity (the relation between subjective and objective cognition) and the relation between metacognitive bias (subjective minus objective cognition) and depression, anxiety, demographics, and PD-related variables. Significant associations were included in linear regression models separately for PwPD and proPD. To assess effect consistency, we examined baseline versus Time 2 difference scores in a subsample who had the same measures 12 months later. RESULTS: ProPD (ρ = .13), but not PwPD (ρ = .08), showed significant metacognitive sensitivity. More negative metacognitive bias was predicted by age, education, depression, and trait anxiety in PwPD (R² = .17) and proPD (R² = .24). The relation between anxiety and negative metacognitive bias was consistent over a 12-month period for PwPD (ρ = -.18; R² = .05). CONCLUSIONS: Negative metacognitive bias, predicted by depression and anxiety, may underlie subjective cognitive concerns in PwPD and proPD, with implications for treatment. These findings support using global approaches to metacognitive awareness, which are likely more accurate measures of daily cognitive awareness than are task-specific measures. (PsycInfo Database Record (c) 2026 APA, all rights reserved).