Investigating ICD-11 adjustment disorder among college students in Taiwan using the Chinese version of the International Adjustment Disorder Questionnaire

<b>Background:</b> The 11th edition of the International Classification of Diseases has redefined adjustment disorder and the International Adjustment Disorder Questionnaire (IADQ) was developed to assess the symptoms and diagnostic criteria. The present study is the first to investigate ICD-11 adjustment disorder using the IADQ in the East Asian context.<b>Methods:</b> We administered standardized self-report measures, including the Chinese version of the IADQ, to a sample of 766 college students in Taiwan, of whom 265 (34.6%) endorsed at least one psychosocial stressor.<b>Results:</b> The two-factor structure of the IADQ reported in previous studies was replicated. The reliability of the two IADQ subscales were high (α = .935 to .948), and they were highly correlated with symptoms of depression, anxiety, and complex PTSD (r_s = .69 to .79, <i>p</i> < .001), demonstrating concurrent validity. In this sample, 5.4% of participants met the diagnostic criteria for ICD-11 adjustment disorder. When participants with probable depression (PHQ-9 ≥ 15) were excluded as per the ICD-11 exclusion rules, 15 participants (1.96%) had probable ICD-11 adjustment disorder.<b>Conclusions:</b> The findings suggest that ICD-11 adjustment disorder can be reliably and validly assessed using the IADQ in the Chinese context. Future studies can use the IADQ to further research the disorder in diverse clinical and nonclinical settings.