Since 2007, China has been actively collaborating with the World Health Organization (WHO) and international colleagues in the revision, field testing, training, and implementation of the ICD-11 chapter on mental, behavioural and neurodevelopmental disorders, and the related Clinical Descriptions and Diagnostic Requirements (CDDR)¹. In 2018, the National Health Commission clearly highlighted the importance of the ICD-11 and requested all health care providers in China to use the ICD-11 in their clinical practice². The ICD-11 CDDR are particularly instrumental to achieving this goal in mental health systems in China, as a vast country with over 30 provincial-level administrative regions and a population of more than 1.4 billion.

The Shanghai Mental Health Center (SMHC), as a WHO Collaborating Centre for Research and Training in Mental Health and a National Center for Mental Disorders, has led the field testing and implementation of the ICD-11 CDDR in China³. Together with other WHO Collaborating Centers in China, National Centers for Mental Disorders, and prestigious institutions across the country, the SMHC has built a core team for ICD-11 CDDR implementation with over 60 national mental health leaders, including heads of leading mental health institutions and presidents of scientific and professional mental health associations. The implementation of the CDDR in China involves an interrelated and growing set of activities including translation, field testing, research, advocacy and training.

Translation is the cornerstone of implementing the ICD-11 CDDR in China. The translation process started in 2016, and was a collective effort by experts from Shanghai, Beijing and Changsha, coordinated by the SMHC. It was an iterative process involving eight rounds of review and revision over eight years, with 24 translators and 12 reviewers contributing to the work. The final Chinese version of the ICD-11 CDDR is now available for all mental health professionals in China.

In conjunction with the translation process, China conducted field testing of the ICD-11 CDDR from 2016 to 2021, following the protocols provided by the WHO. The SMHC was designated as an International Field Study Centre by the WHO, and the president of the SMHC, Min Zhao, was selected as chair of the ICD-11 International Advisory Group on Training and Implementation.

The Chinese field-testing work involved 2,224 patients, 59 clinical raters, 59 referring clinicians, and 23 research assistants from 10 field testing sites nationwide. The field testing was conducted through a rigorous, multidisciplinary and participatory approach, and the results were submitted to the WHO in 2021 to support the ICD-11 CDDR validation and finalization.

In June 2018, after most of the content in the CDDR had been finalized, the SMHC coordinated efforts with various government and professional agencies to discuss a national training plan. In November 2018, the SMHC launched an official training program, strategically designed to disseminate information in a graduated manner by involving a group of psychiatrists representing various regions in China. These psychiatrists were trained and then coached to become trainers at their institutions.

This training program continues to function, and aims to build a network of trainers and a system to disseminate information to clinicians throughout our vast and populous country cost-effectively. Experts continue to provide more specialized training at academic conferences and educational events. Through various methods and channels, and in collaboration with national associations, societies and other specialized institutions, the SMHC has trained over 5,000 psychiatrists to date.

In addition to the above-mentioned work, a series of research and advocacy activities focusing on the ICD-11 CDDR have been organized in China to facilitate better dissemination and implementation. The SMHC has organized and published a series of papers on the CDDR in the Chinese Journal of Psychiatry, the most reputable Chinese psychiatric journal. The series consists of two papers to introduce the CDDR themselves, the progress of their development, and updates on their implementation in China^{4, 5}, and ten papers to introduce significant changes in the diagnosis of major disorders in the ICD-11 CDDR, including anxiety disorders, mood disorders, personality disorders, schizophrenia and other primary psychotic disorders, neurodevelopmental disorders, and disorders due to substance use.

Notably, the series also includes one paper discussing the research progress and controversy related to gaming disorder as a new mental disorder in the ICD-11⁶. Moreover, as knowledge and expertise on gaming disorder are currently lacking in China, the SMHC has led studies and developed a screening tool in Chinese, provided public health recommendations⁷, contributed to the WHO collaborative project on the development of new international screening and diagnostic instruments for the disorder⁸, and organized webinars to enhance the capacity for evaluating and treating the disorder, in collaboration with the WHO and other important partners.

Over more than 15 years of work, several factors have contributed to China's successful implementation of the CDDR. First, China's government plays a crucial role in setting and promoting international standards in national health care. Strong government endorsement for the ICD-11 provides an excellent climate for implementing and disseminating the CDDR. Second, identifying and empowering a local champion for implementing the CDDR in China is essential for providing leadership, overall coordination, resource mobilization, training, quality assurance, change management, and sustainability. Entrusted by the WHO, the SMHC has led implementation efforts and played a vital role in dealing with the immense challenges of implementing a new classification system. Third, public awareness campaigns and stakeholder engagement initiatives have raised knowledge of the benefits of ICD-11 CDDR implementation. Involving stakeholders such as the WHO, the National Health Commission, professional associations, leading research centers, health care professionals, and patient advocacy groups can help foster sustainable momentum and gain essential support for the implementation, contributing to its success.

In the future, we will continue promoting the utilization and dissemination of the ICD-11 CDDR in China, ultimately aiming to scale up mental health care in the country⁹. First, we will continue to deliver nation-wide training on the ICD-11 CDDR for mental health professionals, including psychiatrists, psychologists, general doctors, nurses, social workers, as well as health managers and policy makers. Second, an interactive network for adoption of the ICD-11 CDDR will be developed to advance research, training and clinical initiatives, thereby enhancing the quality of mental health care in the country. Third, further activities – such as developing new auxiliary diagnostic tools, screening tools, and teaching curricula based on the ICD-11 – will be undertaken to facilitate the local adaptation and application of the ICD-11 and the CDDR. Finally, China will continue strengthening international cooperation with international psychiatric experts and organizations to enhance mental health globally.