Metacognitive performance in Functional Cognitive Disorder (FCD): A meta-analysis

Functional Cognitive Disorder (FCD) is defined by persistent subjective cognitive complaints that are inconsistent with objective performance on neuropsychological testing. One leading hypothesis suggests that FCD may involve a dissociation between different forms of metacognition, particularly between global and local self-monitoring mechanisms.

To quantitatively synthesize the evidence for global and local metacognitive performance in individuals with FCD through meta-analysis.

We conducted a systematic review and meta-analysis of studies measuring metacognitive performance in FCD, including comparisons with healthy controls and mild cognitive impairment (MCI). Global metacognition was assessed using self-appraisal metrics, while local metacognition was measured using trial-by-trial confidence accuracy tools such as meta-d'/d'. Effect sizes (Cohen's d) were calculated and pooled using random-effects models.

Three studies were included in the global metacognition analysis, revealing a large pooled effect size indicating impaired global metacognition in FCD (Cohen's d = - 1.07). One study assessed local metacognition and showed no impairment (Cohen's d = 0.00). This supports the proposed dissociation, with preserved local but disrupted global self-monitoring.

Our findings provide meta-analytic evidence for a substantial deficit in global metacognitive insight in individuals with FCD, while local metacognitive abilities remain relatively intact. These results offer a mechanistic explanation for the discrepancy between subjective complaints and objective test performance in FCD. Interventions targeting global metacognitive appraisal may enhance clinical outcomes. Given the very small number of eligible studies, these findings should be interpreted cautiously and viewed as preliminary.