Collective Motivational Interviewing (CMI) for Adolescents With Internet Gaming Disorder

Inclusion Criteria for Adolescents:

* Aged between 10-16
* Probable IGD condition screened by the Internet Gaming Disorder Scale-Short-Form (IGDS9-SF) reaching the cut-off value at 21, those at high risk of having IGD but no IGD cases with clinical diagnosis, although the symptoms measured by IGDS9-SF are equivalent to DSM-5 IGD criteria)
* Hong Kong ID card holder
* Chinese speaking
* Student identity
* Possessing an electronic mobile device or computer
* Willingness to participate in the intervention/control group and complete four surveys (baseline, post-intervention, 3-month follow-up, and 6-month follow-up)
* Can nominate a CSO (e.g., parents) \[client's autonomy is a critical factor to facilitate motivation posited by the self-determination theory (Ryan \& Deci, 2020) (9) to obtain informed consent and parental consent

Inclusion Criteria for CSO:

* Aged greater than 18 years
* Having a close relationship with the adolescent with probable IGD (as rated by participants being generally supportive of the participants)
* Being willing to participate in the present study and provide informed consent

Exclusion Criteria for Adolescents:

* Participants who have psychiatric problems such as psychosis, significant cognitive impairment and/or receiving active and structured psychotherapy about IGD elsewhere will be excluded (Nielsen et al., 2021).

Exclusion Criteria for CSO:

* Participants who have psychosis, aggressive or suicidal behavior
* Having life-threatening medical conditions