Table 3.

Main results found in the assessed studies

N	Authors	Main results
1	Du et al	CBT reduced PIU scores in adolescents, mainly in self-time management compared to CG. The intervention also significantly reduced Internet usage time, improved emotional management and cognitive bias, and reduced internet-related behavior
2	Gholamian et al	BASNEF significantly reduced Internet usage time compared to CG. The intervention also significantly increased the scores for the variables: knowledge; attitude; subjective norms; perceived behavioral control; facilitating factors for Internet use
3	Hui et al	The group that received the combined intervention (CBT + EA) had significantly lower PIU scores and lower levels of anxiety and depression compared to the other groups. The combined intervention also increased the amplitude and latency of P50 of Auditory Evoked Potential in subjects with PIU
4	Ke et al. A	CBT prevented a more damaging progression of PIU and reduced participants’ anxiety, stress, and phobic interaction. These results were maintained 1 month after the study (follow-up)
5	Ke et al. B	CBT significantly reduced the intensity of Internet usage time; PIU score and social anxiety. Most participants were able to manage their Internet usage time better and increase social interaction. These results were maintained 1 month after the study (follow-up)
6	Khazaei et al	PP reduced Internet severity rates and the number of individuals with PIU compared to CG. The authors also reported that PP promoted an improvement in the quality of social relationships
7	Kim et al	CBT reduced PIU, anxiety and depression scores in adolescents compared to CG. After 1 month, the PIU scores were lower than baseline, but the intensity of anxiety and depression symptoms was even lower immediately after the program
8	Pan	The combined intervention (CBT + PE) significantly reduced the other groups’ PIU symptoms (time and motivation to use the Internet)
9	Quinones et al	The MDF and GR interventions were equally effective in reducing symptoms of anxiety and depression, and the MDF had a significantly greater effect in reducing PIU
10	Santos et al	CBT combined with medication significantly reduced PIU and anxiety compared to PPE group participants
11	Tas et al	PPE significantly reduced PIU, and psychological symptoms compared to CG. It was effective in reducing psychological symptoms and Internet addiction. These results were maintained 45 days after the end of the study (follow-up)
12	Thorens et al	Participants undergoing CBT significantly improved their PIU symptoms and CGI score concerning themselves before the intervention
13	Yang et al	Both EA and PP reduced PIU scores, and EA more intensely reduced scores related to PIU subfactors (behavioral control, impulsivity control, and protection of brain neurons)
14	Young	CBT significantly reduced PIU scores from baseline. In addition, more than 95% of participants improved the way they manage PIU-related symptoms. Almost 80% of these participants remained recovered 6 months after the study (follow-up)
15	Zhu et al	In the three groups (EA; CT; EA + CT), a reduction in PIU scores and an increase in short-term memory capacity was detected. In the CT group, the PIU scores were even lower compared to the other groups

Legend: CBT, cognitive-behavioral therapy; PIU, problematic Internet use); CG, control group; BASNEF, Belief, Attitude, Subjective Norm, and Enabling Factors); EA, electroacupuncture; PP, positive psychology; PE, physical exercise; MDF, mindfulness; GR, gradual relaxation; PPE, psychoeducational program; CGI, Clinical Global Impressions; CT, comprehensive therapy