Three key lessons learned from over a decade of gaming disorder assessment research.

Since the recognition of internet gaming disorder (IGD) in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders and gaming disorder (GD) in the eleventh revision of the International Classification of Diseases, significant progress has been made toward standardizing assessment practices. However, the present paper argues that three key lessons can be derived when considering the advancements in the field over the past decade. Firstly, rather than developing additional instruments, the field would greatly benefit from unifying existing assessment frameworks and establishing a clinical 'gold standard' based on current diagnostic criteria. Secondly, continued development of psychometric assessment alone is insufficient because the field urgently needs a robust theoretical framework that is able to distinguish between excessive and disordered gaming effectively. Without sound a theory, assessment and treatment practices risk ongoing conceptual drift and fragmentation. Finally, despite recent criticisms regarding the use of psychometric instruments and self-report measures, these methodologies remain necessary. While more objective gaming data can be valuable, they also present with important limitations that need to be fully considered. A potential way forward for an effective assessment approach may involve combining both psychometrically robust self-report data with objective data. However, future research must still ensure that assessment instruments undergo rigorous psychometric validation beyond reliability and validity alone. The paper concludes that instead of prioritizing the development of new assessment tools, the field would benefit more from strengthening its theoretical foundation and rigorously evaluating existing diagnostic frameworks and psychometric instruments.