and neurodevelopmental disorders contains new controversial diagnoses including compulsive sexual behavior disorder (CSBD), intermittent explosive disorder (IED) and gaming disorder. Using a vignette-based methodology, this field study examined the ability of mental health professionals (MHPs) to apply the new ICD-11 diagnostic requirements for impulse control disorders, which include CSBD and IED, and disorders due to addictive behaviors, which include gaming disorder, compared to the previous ICD-10 guidelines. Methods: Across eleven comparisons, members of the WHO?s Global Clinical Practice Network (N 5 1,090) evaluated standardized case descriptions that were designed to test key differences between the diagnostic guidelines of ICD-11 and ICD-10. Results: The ICD11 outperformed the ICD-10 in the accuracy of diagnosing impulse control disorders and behavioral addictions in most comparisons, while the ICD-10 was not superior in any. The superiority of the ICD-11 was particularly clear where new diagnoses had been added to the classification system or major revisions had been made. However, the ICD-11 outperformed the ICD-10 only in a minority of comparisons in which mental health professionals were asked to evaluate cases with non-pathological high involvement in rewarding behaviors. Discussion and Conclusions: Overall, the present study indicates that the ICD-11 diagnostic requirements represent an improvement over the ICD-10 guidelines. However, additional efforts, such as training programs for MHPs and possible refinements of diagnostic guidance, are needed to avoid over-diagnosis of people who are highly engaged in a repetitive and rewarding behavior but below the threshold for a disorder.  Kulcsszavak: compulsive sexual behavior disorder, gambling disorder, gaming disorder, pyromania, kleptomania, intermittent explosive disorder