Instrumental assessment of psychotic disorders in intellectual developmental disorders and autism with cognitive or major communication issues

PURPOSE OF REVIEW: The high comorbidity and complex clinical presentation of psychotic disorders in adults with intellectual developmental disorders (IDDs) and autism spectrum disorder with cognitive or major communication issues (ASD-CMCI) requires highly accurate assessment approaches. This targeted review examines the availability, validity, and clinical utility of existing instruments for this high-risk population, in whom diagnostic procedures are often hindered by communication deficits and diagnostic overshadowing. RECENT FINDINGS: There is a substantial lack of PD-specific assessment tools for this population. Adapted neurotypical scales, including the PANSS and PSYRATS, demonstrate limited validity because they rely heavily on introspective self-report. The primary methodological challenge is distinguishing chronic neurodevelopmental features from acute psychotic change, a process that requires careful observation of objective deviations from the individual's baseline functioning and behaviour. SUMMARY: This targeted review underscores the need for dedicated, informant-based instruments for PD in IDD/ASD-CMCI. Approaches grounded in behavioural equivalents and systematic evaluation of change from baseline appear essential for reducing diagnostic overshadowing and improving diagnostic accuracy, although further validation of these methods remains necessary.