Abstract: A growing body of research has examined the association between childhood maltreatment and internet addiction. Results of these research are inconclusive, and the strength of the association between childhood maltreatment and internet addiction varied greatly, ranging from -0.1 to 0.56. The Interaction of Person-Affect-Cognition-Execution (I-PACE) model suggests that childhood maltreatment could influence an individual's emotion, cognition, and executive function, potentially leading to internet addiction. The Compensatory internet use (CIU) model proposes that individuals who have experienced childhood maltreatment may turn to the internet as a coping mechanism to avoid negative emotions and real-life problems. The self-determination theory indicates that childhood maltreatment can increase the risk of excessive internet use by hindering the fulfillment of basic psychological needs. The stress coping theory indicates that the severity of childhood maltreatment could impact the development of internet addiction as a coping strategy in dealing with stress in real life. While theories and research suggest that childhood maltreatment can contribute to the development of internet addiction, results have been inconsistent. Therefore, this meta-analysis aimed to estimate the extent to which childhood maltreatment is associated with internet addiction, and whether this association varies in terms of characteristics of the study or sample, such as the type of childhood maltreatment, gender, age, etc.
A systematic literature review was conducted in Science Direct, EBSCO, Google Scholar, CNKI (China National Knowledge Infrastructure), CSTJD (China Science and Technology Journal Database) and WFD (Wanfang Data). A three-level meta-analysis was performed using R to synthesize effect sizes and conduct moderator analyses. Publication bias was assessed using funnel plots and Egger's regression.
A total of 46 studies (N = 106,780 participants) producing 152 effect sizes were included in this meta-analysis. The result indicated a significant positive association between childhood maltreatment and internet addiction, with a small correlation coefficient (r = 0.227). Moderator analyses revealed that the type of childhood maltreatment had a significant moderating effect. Specifically, the association between childhood maltreatment and internet addiction was significantly higher for emotional abuse than for emotional neglect, physical abuse, physical neglect and sexual abuse. Additionally, the association between childhood maltreatment and internet addiction was moderated by the severity of maltreatment, the measurement of maltreatment, the proportion of only child in the sample, gender, and cultural background. Compared to the high maltreatment group, the correlation coefficient between childhood maltreatment and internet addiction was significantly larger in the low maltreatment group. The correlation was significantly higher when childhood maltreatment was measured by using the Childhood Trauma Questionnaire than by using other scales. The positive correlation between childhood maltreatment and internet addiction decreased as the proportion of female and only child in the sample increased. The correlation between childhood maltreatment and internet addiction was greater in Eastern culture than in Western culture. The type and measurement of internet addiction, age, data type, and the timing of data collection did not moderate the association between childhood maltreatment and internet addiction.
This study not only provides supports for diverse theoretical perspectives, including the self-determination theory, the CIU model, the I-PACE model, and the stress coping theory, but also offers a deep understanding of the association of early traumatic experiences and internet addiction. By identifying moderators such as the type and severity of maltreatment, measurement, demographic variables and cultural background, this research provides a solid foundation for prevention and intervention of internet addiction.

Key words: childhood maltreatment, severity of maltreatment, emotional abuse, internet addiction, meta- analysis