Effects of different interventions on internet addiction: a systematic review and network meta-analysis

Inclusion criteria: (1) Published studies on randomized controlled trials on IA, regardless of whether allocation concealment and blinding were mentioned in Chinese or English language; (2) Study subjects meeting one of two criteria: (a) Diagnosis criteria for IGD in DSM-5, Young's Diagnostic Questionnaire for IA, 1997 American Psychological Association Diagnostic Criteria for IA, or other clinical diagnostic criteria for IA; (b) A score of 40 or higher on either the Internet Addiction Test (IAT) or Chen's Internet Addiction Scale (CIAS) [10‐12]; (3) Various scores from relevant internet addiction scales were used as evaluation indicators for the treatment effects of different intervention measures and their combinations; (4) Data extraction was limited to studies with full texts only.

Exclusion criteria: (1) Review systematic reviews; (2) Duplicate literature and non-peer-reviewed material; (3) Studies with outcome indicators that failed to meet the inclusion requirements or had apparent errors or omissions.

To identify studies that comply with the inclusion criteria, computer searches were performed in several databases, including PubMed, Embase, Web of Science, Wanfang, and China’s National Knowledge Infrastructure (CNKI). The databases were searched up to December 31, 2022, using a combination of controlled vocabulary and free text terms according to each database's search rules. The search terms included: Internet gaming addiction, electronic gaming addiction, online gaming, pathological internet use, addictive internet use, gaming disorder, internet addiction, excessive internet use, computer game addiction, internet dependence, efficacy, randomized, drug therapy, psychotherapy, antidepressants, cognitive behavior, randomized controlled, case–control, clinical trial, intervention, bupropion, methylphenidate, aripiprazole, sertraline, and fluoxetine. Two investigators independently conducted computer and manual searches, with a third expert consulted in the event of disagreement.

Two researchers independently conducted literature screening following the predetermined inclusion and exclusion criteria. The retrieved literature was imported into literature management software and initially screened by title and abstract after duplicate removal. This led to a thorough reading of the complete text and the final decision regarding inclusion. All data were cross-checked and extracted from the included literature and any discrepancies were resolved by consultation with a third party. The data extracted included basic information about the literature, intervention measures, and outcome indicators.

Two researchers strictly assessed the quality of the included studies according to the Cochrane Handbook for Systematic Reviews of Randomized Trials. Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0. The Cochrane Collaboration). The tool includes seven items: random sequence generation, allocation concealment, blinding of participants and personnel, blinding of outcome assessment, incomplete outcome data, selective reporting, and other biases. Each item was assessed as "low risk," "unclear risk," and "high risk."

The network Meta-analysis package of Stata14.2 was used for network meta-analysis and drawing the network map, and RevMan5.4 was used to evaluate the quality of the included studies. In the statistical process of network meta-analysis, since the outcome measurement indicators of the included studies were continuous data and the scale scoring methods of each study were different, the standard mean difference (SMDs) of different studies and the corresponding 95% confidence intervals (CIs) were used as the effect size to merge the results. First of all, the collected data is tested with the inconsistency model to check whether there is good consistency between the groups and the local areas. If there is consistency, the consistency model is used for further analysis of the data; if the inconsistency is significant, the consistency model cannot be used for subsequent steps. Then, the processed data were sorted using surface under the cumulative ranking curve (SUCRA) values [13], and all the processing results were summarized in a rank-heat map [14] to obtain the ranking of the therapeutic effects of various interventions. The SUCRA value refers to the area under the cumulative sequencing probability curve of an intervention, with the value ranging from 0 to 100%. League tables were also drawn to analyze pairwise comparisons between interventions, including SMD values and 95% confidence intervals. Finally, the funnel plot was drawn using Stata 14.2 to identify whether there was a small sample effect.

A preliminary search yielded 809 English-language studies and 3012 Chinese-language studies. After reviewing the titles and abstracts, 383 articles remained; following a duplication check and full-text reading, 57 studies were finally included for the network meta-analysis, comprising 63 comparisons. The steps for literature retrieval are shown in Fig. 1.

The characteristics of 57 included studies [3, 15‐70] are shown in Table 1, which involved 13 interventions, including psychotherapy/CBT, group psychotherapy, Mindfulness-Based Cognitive Therapy (MBCT), placebo/non-intervention, health education, exercise therapy, electro-acupuncture, drug, EEG biofeedback, rTMS, rTMS + CBT, drug + others, and electro-acupuncture + CBT. A total of 3538 patients with IA were included, and all included studies had comparable descriptions.

Two reviewers strictly followed the recommended bias risk assessment tools in the Cochrane Handbook to assess the risk of bias for the included studies. For example, in terms of randomization methods, 22 studies were evaluated as "low risk" as they adopted randomized allocation methods such as random number tables, stratified randomization, and drawing lots. Another 28 studies only mentioned "randomization" without reporting specific randomization methods and were evaluated as "unclear risk." The remaining seven studies randomly assigned patients according to the admission order and were rated "high risk." All studies failed to report whether allocation concealment was performed and was rated as “unclear risk." Seven studies involved blinding and were rated as "low risk." All studies had complete data and were rated as "low risk." Other biases were not mentioned and were rated as "low risk."

The consistency of each closed-loop result was tested. Inconsistency factors (IF) showed p = 0.4042, indicating good consistency. All local p > 0.05, indicating good consistency among all groups.

The research was roughly symmetrically distributed on both sides of the midline, indicating that a small sample effect was less likely to exist as shown in Fig. 5.

Based on the efficacy ranking, both rTMS combined with CBT and rTMS alone achieved optimal treatment effects. Compared with all other interventions except for drug-combined comprehensive treatment, rTMS combined with CBT has shown statistical differences. rTMS is a physical therapy that generates a sequence of repetitive electromagnetic pulses through an electromagnetic coil. It can regulate cortical excitability by acting on specific cortical regions of the brain [71]. Numerous domestic and foreign studies have shown that rTMS has immense potential to treat substance dependence [72]. Studies have shown that rTMS treatment targeting the left or right dorsolateral prefrontal cortex (DLPFC) can fully mobilize the cognitive regulatory capacity of the DLPFC, increase the excitability of cortical areas, and regulate activity by maintaining functional levels of dopamine and other neurotransmitters in various structures of the reward circuit [73]. Thus, people's cravings for the Internet will be reduced, and their addictive behavior will be curtailed. Furthermore, neuroimaging studies have also found that rTMS applied to DLPFC can effectively inhibit brain cortices related to addictive behavior and sensation, reduce the craving of participants with IA, improve their cognitive control and emotional regulation abilities, reward and cognitive control systems, and thereby reduce the craving and behavior in IA [74, 75]. IA can significantly reduce the white matter integrity of DLPFC compared to normal individuals [76], similar to the changes observed in drug addiction. Excessive use of the internet can alter the reward and pleasure centers of the brain, making it difficult to quit addiction. rTMS can help regulate brain activity and reduce cravings related to IA.

Simultaneously, CBT is also a major intervention method for IA in psychotherapy, which is effective in many randomized controlled studies on IA [77, 78]. The essence of CBT is to correct the cognitive dysfunction of patients with IA. Improving cognitive control ability may be the key to solving IA [79]. The results of the network meta-analysis demonstrated that rTMS combined with CBT treatment was more effective than rTMS or CBT alone. When people try to reduce or withdraw from online activities, IA can lead to withdrawal symptoms. Physical therapy interventions can help control these physiological and emotional withdrawal symptoms, making it easier for patients to receive psychological treatment. Therefore, people's desire for the internet will decrease and their addictive behavior will be restricted [80]. This could be attributed to the potential of combined treatment to simultaneously improve the physiological, psychological, and behavioral aspects of IA, thereby producing a cumulative effect for better outcomes.

Medication combined with other intervention measures, as a comprehensive intervention measure, demonstrates excellent efficacy, outperforming single medication therapy. Many experts believe that IA indicates impulse control disorders over the internet. This addictive behavior is classified as compulsive behavior [81]. Researchers suggest that selective serotonin reuptake inhibitors (SSRIs), as first-line drugs for treating obsessive–compulsive disorder, may also have optimal therapeutic effects on patients with IA. The results of our meta-analysis indicated that the efficacy of single drug therapy is only superior to that of the general intervention group, the placebo group, and the single electro-acupuncture group and is comparable to that of a single psychological treatment. However, when combined with psychological or physical treatment, it demonstrates excellent results and is statistically significant compared to single-medication therapy. This may result from medication therapy controlling anxiety and depression to a certain extent in IA patients. For IA patients with poor self-control and resistance to treatment, applying medication first to stabilize the patient's emotions and then using psychological or physical treatment can further improve their depressive and anxious symptoms and cognitive function, thereby reducing their craving for the internet. Additionally, combined therapy can reduce the adverse effects of the long-term use of single medications and improve treatment safety, resulting in better outcomes.

We also noticed that the combination of electro-acupuncture and CBT treatment had achieved unexpected results. Traditional Chinese medicine has a long history of application in mental illnesses, such as using electro-acupuncture to treat depression and sleep disorders. Studies have demonstrated that electro-acupuncture can promote the recovery of neurons in the affected brain area [82]. The acupoints used in acupuncture can increase blood flow or induce electrical potentials in specific brain regions [83]. As a commonly used treatment in traditional Chinese medicine, Electro-acupuncture therapy has gained recognition in treating modern addictive behaviors. The combination of electro-acupuncture and CBT treatment was shown to significantly reduce the addiction level and related clinical symptoms of IGD patients. fMRI is increasingly being used to study the mechanism of acupuncture. Previous studies have confirmed that acupuncture and moxibustion can regulate the structure and function of the brain regions of drug addicts and can regulate the functional connection between the reward and habit systems of IA [84]. Therefore, the regulatory effect of acupuncture on the brain area of network addiction patients may be a potential mechanism of acupuncture in-network addiction. Both electro-acupuncture and cognitive-behavioral therapy have significant positive effects on network-addicted adolescents. Both treatment methods effectively improve network addiction patients' psychological experience and behavioral expression. However, electro-acupuncture is more effective than psychological therapy regarding impulse control and neuron protection. This advantage may be related to increased NAA and CHO levels in the prefrontal cortex and anterior cingulate cortex [82]. The combination of electro-acupuncture and psychological interventions (cognitive-behavioral therapy, group, psychological therapy combined with individual psychological therapy) can alleviate the mental symptoms, sleep quality, and impulse characteristics of network addiction patients [85]. Its mechanism may be related to increased brain sensory perception gate function. Psychological intervention can help relieve the fear of electro-acupuncture and improve the treatment effect, as acupuncture is an exogenous stimulation that usually accompanies pain. Combining CBT with electro-acupuncture treatment has shown superior results compared to using acupuncture alone, suggesting a synergistic effect between electro-acupuncture and CBT. In summary, combining electro-acupuncture and CBT can achieve optimal therapeutic outcomes.

Compared to comprehensive treatment, we have observed that the following five interventions, namely health education, electro-acupuncture, place/non-intervention, MBCT, and drug treatment, have relatively lower effectiveness. We believe this may be attributed to the following reasons. Health education often focuses on encouragement, comfort, and providing knowledge related to IA, but it fails to address the deep-rooted inner struggles of patients and alleviate their dependency on the internet. Therefore, health education is generally less effective in most cases. As for electroacupuncture treatment, studies have shown that IA patients often experience strong withdrawal reactions during the initial stages of treatment, such as restlessness, palpitations, and irritability. As an acupuncture treatment, electroacupuncture may cause swelling and heaviness at the treatment site, and discomfort may persist for a period of time after the needles are removed and gradually subside. Consequently, the compliance and expectations of most patients are not high, resulting in mediocre therapeutic effects of using electroacupuncture alone.

MBCT, as a mindfulness and meditation-oriented treatment method, has been shown in research to reduce craving for IA by improving the understanding ability of IA patients, improving loneliness in IA, and reducing heart rate and cortisol levels [23]. However, due to the impulsive personality traits of most addiction patients, many individuals are unable to calm their minds and fully engage in the understanding and experience provided by MBCT therapy. Therefore, relying solely on MBCT treatment is ineffective.

The use of drugs alone also fails to achieve better therapeutic effects, mainly because in simple applications of drug therapy, common SSRIs such as sertraline, which selectively inhibit the reuptake of serotonin by central neurons, leading to an increase in serotonin concentration, have slow-acting effects and are associated with side effects such as gastrointestinal discomfort. Consequently, patients have low long-term medication tolerance and poor treatment effectiveness. Moreover, the cognitive function of patients is still insufficient in medication-only treatment [3]. On the other hand, combination therapy and comprehensive treatment can reduce the adverse reactions caused by long-term medication use, enhance treatment safety, and improve treatment effectiveness. Therefore, a single treatment approach may not be able to address all the issues, and personalized comprehensive treatment plans should be developed based on the unique characteristics of each patient during clinical treatment to ensure compliance and treatment effectiveness.

IA is a complex multifactorial disorder with numerous physiological, psychological, and social elements. A single treatment plan can have difficulty addressing all issues, while a comprehensive therapy can integrate the advantages and disadvantages of various treatments and take targeted measures. Although the findings of this study confirm the safety and feasibility of electro-acupuncture + CBT therapy for IA, there are still some limitations. Due to time constraints, the long-term efficacy of the subjects has not been observed, and the effectiveness assessment was based on clinical scales. Therefore, it is possible that subjects may have concealed some information during the measurement.

(1) Most of the studies were conducted by Chinese researchers. (2) The literature on rTMS combined with CBT treatment and drug combinations with other treatments included in this study was limited.