Metacognition in gambling disorder: A systematic review and meta-analysis

Introduction: In recent literature, abnormalities in the metacognitive domain have been pointed out as psychological variables that may account for a wide range of psychopathologies, including gambling disorder (GD). Considering the growing but scattered nature of the research concerning the relationship between metacognition and GD, a systematic review and meta-analysis of the existing results are required. Methods: We performed a systematic search through five scientific databases for research published till December 10, 2019, following PRISMA guidelines. We also searched grey literature. After removing the redundancy, 16.855 records were screened. Results: Unanimously, authors selected 10 articles based on the inclusion criteria. Four of the selected studies evaluated metacognitive abilities towards cognitive performances, mostly considering metacognitive deficits about decision-making, while metacognitive beliefs were assessed by six of the selected articles. Only one study examined metacognitive functioning regarding GD. The meta-analytic procedure was performed on 10 identified studies based on the criteria adopted, which comprised 1.655 individuals. Results showed that the average effect size linking metacognitive dysfunctions and GD was significant and moderated by the instrument used to measure metacognition. Conclusions: The examined line of research is highly heterogeneous owing to the type of operationalization adopted for metacognition. The systematic review also showed a grey area, evidencing the lack of research on metacognitive functions. Results demonstrated by this meta-analysis call for future studies examining the role of metacognitive deficits in GD in order to delineate useful clinical indications.