Background and aim: The 11th Revision of the International Classification of Diseases (ICD-11) recognizes gaming disorder (GD) as a behavioral addiction, but its implications for the clinical diagnostic practice of GD remain underexplored. This study examines the clinical diagnosis of GD since its inclusion in ICD-11 to understand trends in diagnosis rates in psychiatric departments and patient characteristics, particularly comorbidities. Method: This multicenter, retrospective observational study was conducted in five large tertiary hospitals and mental health centers across four Chinese provinces. Diagnoses of GD in each hospital were based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) or ICD-11 criteria. Data were extracted from hospital records, including demographics, diagnoses, and medical history. Result: Of the 7,877,415 total visitors, 3,517 unique patients (0.045%) met GD diagnostic criteria. GD diagnoses showed a significant linear increase (÷2 5 83.143, p < 0.001) from 2018 to 2023. 37.59% of GD patients had comorbidities, mostly mood disorders, followed by impulse control disorders, schizophrenia or other primary psychotic disorders, and attention deficit hyperactivity disorder. Patients were younger (F 5 48.69, p < 0.001), mainly aged 12-18. Discussion and conclusions: This study reveals an upward trend in GD diagnosis from 2018 to 2023, showing a trend toward younger diagnosis age, especially in males. Notably, there?s a high rate of comorbidities, with mood disorders being the most common. While ICD-11 may have improved GD identification, further research is needed to clarify whether the increased rates are due to higher prevalence or better recognition.  Kulcsszavak: behavioral addiction, gaming disorder, ICD-11, diagnostic trends, comorbidity, rejuvenation