Abstract
Impaired metacognition, the capacity to understand one's own and others' mental states, has gained increasing attention in psychosis research. Different conceptualizations, psychological treatments and assessment methods have emerged; however, there is a lack of consensus regarding the appropriate tools for clinical and research use. This systematic review had two aims: (1) to compile and organize available assessment tools and (2) to propose an index of metacognitive domains and processes. Instruments were categorized according to authorship, year of use in psychosis, outcomes assessed, language/version, administration time and type of Clinical Outcome Assessment (ClinRO, PRO or PerfO). We identified 42 studies that used 31 instruments. The tools were classified into four domains: Metacognitive Awareness, Metacognitive Capacity, Neurometacognition and Social Metacognition. Our findings highlight the diversity of the available measures and propose a framework for aligning instruments with specific reflective processes. This work represents a practical and theoretical first step toward building consensus and facilitating both the use of available tools according to practical needs and the development of an agreed-upon definition and components of metacognition.