Effectiveness of non-invasive interventions for internet gaming disorder: A meta-analysis of randomized controlled trials

Table 1 Characteristics of randomized controlled trial studies included in the final analysis (n = 11)

No	Ref.	Country	Sample size	Age group	Intervention	Control group	Summary of main results
1	Hong et al[1]	South Korea	50	Males, 15-18 years	CBT + physical exercise program	CBT + supportive counseling	Both groups showed a reduction in gaming addiction severity; the exercise group showed greater improvements in mood and frontal alpha asymmetry
2	Jeong et al[2]	South Korea	26	Young adults	Bilateral DLPFC tDCS (12 sessions)	Sham tDCS	The active tDCS group showed reduced gaming cravings and gaming time, along with changes in brain glucose metabolism
3	Fu et al[3]	China	51	University students	ABM	Sham training	The ABM group showed greater reductions in gaming cravings, IAT scores, and Decreased DSM-5 criteria score
4	Lee et al[4]	South Korea	26	Adults	tDCS (alpha frequency) + Cognitive Training	Sham tDCS	The active tDCS group showed some reduction in craving intensity and IGD scores, but effects were not sustained at follow-up
5	Nielsen et al[5]	Switzerland	42	12-19 years	Multidimensional family therapy (MDFT)	Standard Family Therapy	Both groups showed reduced IGD symptoms; the MDFT group had superior outcomes in reducing the number meeting IGD criteria
6	Brailovskaia et al[6]	Germany	271	Mean: 26 years	2-week gaming abstinence program	No intervention (usual gaming)	Reduced gaming time and IGD symptoms, lower stress and anxiety, improved positive mental health; effects maintained at 1 and 3 months
7	Lindenberg et al[7]	Germany	422	Adolescents	PROTECT Program (CBT-based group)	Waitlist	PROTECT participants showed reduced problematic gaming and improved attitudes towards gaming; effect size was small but significant
8	Maden et al[8]	Turkey	44	Young adults	VRT or adventure therapy	Waitlist	Both VRT and adventure therapy groups showed reductions in gaming time and IGD scores; VRT was slightly more effective
9	Dieris-Hirche et al[9]	Germany	162	Adults	OMPRIS (Webcam-based CBT + ACT)	Waitlist	The OMPRIS group showed significant reductions in IGD symptoms and gaming time, with effects maintained at 6 months
10	Ede et al[10]	Nigeria	40	Young adults	Group CBT (8 weeks)	Waitlist	The CBT group showed a large reduction in gaming problem scores and reported improved social functioning
11	Ji and Wong[11]	China	77	Adolescents	iCBT	Waitlist	The iCBT group showed reductions in IGD scores and weekly gaming time, with approximately 30% showing clinically meaningful improvements

CBT: Cognitive behavioral therapy; tDCS: Transcranial direct-current stimulation; IGD: Internet gaming disorder; ACT: Acceptance and commitment therapy; VRT: Virtual reality therapy; ABM: Attentional Bias Modification; iCBT: Internet-based cognitive behavioral therapy.

Table 2 Risk-of-bias assessments

Ref.	Domain 1: Randomization process	Domain 2: Deviations from intended interventions	Domain 3: Missing outcome data	Domain 4: Measurement of the outcome	Domain 5: Selection of the reported result	Overall risk of bias
Hong et al[1]	Low	Low	Some concerns	Low	Low	Some concerns
Jeong et al[2]	Low	Some concerns	Low	Low	Low	Some concerns
Fu et al[3]	Low	Low	Low	Low	Low	Low
Lee et al[4]	Low	Some concerns	Low	Low	Low	Some concerns
Nielsen et al[5]	Low	Low	Low	Low	Low	Low
Brailovskaia et al[6]	Low	Low	Low	Low	Low	Low
Lindenberg et al[7]	Low	Low	Low	Low	Low	Low
Maden et al[8]	Low	Low	Low	Low	Low	Low
Dieris-Hirche et al[9]	Low	Low	Low	Low	Low	Low
Ede et al[10]	Low	Low	Low	Low	Low	Low
Ji and Wong[11]	Low	Low	Low	Low	Low	Low

The judgments are based on the RoB 2 tool's criteria, where each domain is assessed as 'Low', 'Some concerns', or 'High' risk of bias. The overall risk of bias for each study is determined by the highest risk level in any domain, unless there are specific reasons to override this judgment.