Internet addiction in adolescents: Development and validation of Internet Addiction Diagnostic Questionnaire (KDAI).

Internet addiction (IA) is an emerging behavioral problem that constitutes a major health threat to vulnerable populations, including adolescents. However, there is a paucity of IA screening tools specifically designed for adolescents, especially in Indonesia. Therefore, the current study developed and validated the IA Diagnostic Questionnaire (KDAI) in adolescents while acknowledging local cultural influences. The KDAI was conceived through extensive literature reviews, expert discussions based on Delphi methods, a face validity study, focus group discussion (N = 31) for initial reliability testing, and a recruited pilot study (N = 385) and main study (N = 643) for exploratory and confirmatory factor analyses, respectively. The multi-sample analyses demonstrated that the KDAI model with the best fit and reliability comprised a seven-factor structure, including withdrawal, loss of control, increase of priority, negative consequences, mood modification, salience, and impairment. These factors were scrutinized against domains of IA Test, and concurrent validity was ascertained. Subsequently, a receiver operating characteristic curve and area under the curve determined a cutoff score of 108 to discern adolescents with IA. Taken together, the KDAI displayed excellent psychometric indices and sensitivity as a screening tool for IA in adolescents.