Our review brings all related studies together to explore the association of problematic internet use on the mental health conditions of left-behind children and adolescents. The qualitative synthesis highlights a range of psychological and behavioral problems, including anxiety, depression, suicide, personality, academic problems and other cognitive or behavior problems.
We found three major emotional disorders related to problematic internet use in this review: anxiety, depression and even suicidal ideation. Long-term internet use has been linked to increased rates of anxiety and depression among teenagers worldwide30,42,43 due to its impact on healthy activities, sleep patterns, and brain development.30 Internet addiction can also lead to physical health problems such as dyspepsia, nausea, and anorexia, which are associated with abnormal dopamine secretion, a neurotransmitter that reduces anxiety and depression.21 Additionally, internet addiction can increase sensitivity to the environment, causing teenagers to worry excessively and become anxious even when nothing has happened.21 For left-behind children, parental separation is a major negative life event, and a risk factor for anxiety and depression. The loss of parental support and inadequate supervision by caregivers can lead to withdrawal symptoms, low self-confidence and low self-esteem among left-behind children.2,44 Internet use can further reduce their communication with parents and peers, contributing to low subjective well-being.40 Due to the incomplete family structure, left-behind children may lack opportunities for psychological communication. As a result, some children and adolescents with symptoms of mental health problems may not receive adequate counselling in real life, leading to the accumulation of negative emotions over time.17,35,45 When faced with problems such as poor academic performance, lack of friends, or being bullied in reality, left-behind children may turn to the internet as an outlet for expressive emotions.2,4 However, this does not solve their real-life problems and may exacerbate negative emotions, leading to more serious mood disorders.21 In severe cases of depression and anxiety, some individuals may develop suicidal thoughts. Consistent with our finding, a Japanese study (n = 17 920) found a strongly association between internet addiction and suicidal tendencies.46 Additionally, suicidal ideation may progress to suicide planning and attempt without timely and effective intervention.11 It is important to strengthen emotional screening for left-behind children with internet addiction and provide interventions to prevent the development of serious emotional disorders.
We also identified three important personality traits : psychoticism, neuroticism and introversion. Studies have reported that internet addicts among normal teenagers exhibit higher levels of neuroticism, psychoticism, introversion, and shyness.35,47,48 Our research corroborates these findings among left-behind children and adolescents. The internet can serve as a surrogate parental figure for left-behind children and adolescents, providing temporary comfort and satisfaction when they encounter difficulties or frustration in their daily lives. These children can alleviate negative emotions and derive a sense of achievement and satisfaction by engaging in online activities. However, this can ultimately lead to the development of compulsive internet addiction.21 As teenagers have not yet fully developed their critical thinking abilities or establish mature views on life and values, this addictive tendency can result in the internalization of unhealthy online information, leading to changes in behaviors and characters and an increased propensity to develop negative personalities.21,35,49 Individuals with negative personality traits, particularly those with internet addiction, exhibit maladaptive emotional and behavioral patterns, including anger, loneliness, helplessness, depression, anxiety, impulsiveness, and weakness.35,49,50 These characteristics can impede the ability of left-behind children to adapt to their external environment, negatively impacting their academic performance and overall well-being. This can result in further reliance on the internet as a coping mechanism, perpetuating a vicious cycle of addiction.
This review has also demonstrated that left-behind children and adolescents with internet addiction are at increased risk of developing learning difficulties, including academic procrastination, disengagement, and inattention. In the absence of timely parental guidance and support, these individuals may turn to the internet as a means of escaping their academic challenges or increasing their emotional satisfaction.5,36,51,52 Students who spend more time on the internet are likely to spend less time on academic pursuits,5,53 and the excessive internet use can distract them from academic tasks.5,54−57 Academic engagement, an important component of students’ academic adjustment, is characterized by a sustained, positive cognitive and emotional investment in learning.37,58 When left-behind students overuse the internet, their psychological resources become depleted, reducing the resources available for academic engagement and negatively impacting their academic performance.37,59 Furthermore, internet addiction can impair cognitive function, reducing concentration and leading to low academic persistence and procrastination.5,60,61
Left-behind children often lack timely parental support and may turn to mobile devices to connect with others and fulfill their need for interpersonal warmth. This can result in feelings of estrangement from their parents and a lack of trust and attachment in future social relationships. Heightened sensitivity to interpersonal relationships can lead to increased social anxiety and poor interpersonal skills in real life. As a result, these individuals may turn to the internet to establish and maintain social connections as a means of satisfying their higher psychological needs for autonomy, self-esteem, and self-actualization. This can result in a form of “pathological compensation” .2,9,17,37,44 However, the virtual relationships established through the internet are often unstable and can create a disconnect between individuals and real-world social interactions, hindering the development of interpersonal communication skills. Internet-addicted individuals may lack these skills, resulting in weakened family bonds and reduced communication.17,21 Furthermore, internet addiction and exposure to harmful online information can further distance left-behind children from social interaction Both Davis’s cognitive behavioral model and Anderson and Bushman’s aggressive behavior model emphasize the priming effect of excessive internet use on individual cognition and external stimuli.1,62,63 As a result, children addicted to the internet develop may develop maladaptive behaviors such as aggression and pornography addiction.62,63
Labour migration is a global trend that has been significant in low-income and middle-income countries (LMICs), resulting in a growing number of children and adolescents being left behind. Addressing the mental health needs of these left-behind children is a critical priority for healthcare providers and policy-makers. The negative impact of problematic internet use on physical and mental health also have been a public health concern, but due to limited access to computers and mobile devices in low-income countries, all studies included in our systematic review were conducted in China. This may potentially limit the generalisability of our findings to other settings, particularly in low-income countries. Nonetheless, our findings focused on the mental and emotional health of left-behind children and provide valuable insights into the potential mental health needs of this population, helping health-care providers and policy-makers to better understand the challenges and opportunities they face.3,64
Limitations and strengths
We conducted a comprehensive systematic review that included a board coverage of relevant studies using rigorous methods to examine these issues. Our review identified twelve mental health conditions in the emotional, personality, academic and interpersonal areas of the internet use in the 19 included papers.
Nevertheless, our study has some limitations. First, although we conducted a comprehensive and systematic search, the number of relevant studies was limited and there were few homogeneous studies on each issue, so we could not conduct a meta-analysis. Second, although we did not restrict by country, the included studies were all conducted in China, making it difficult to disseminate the results globally. Third, the study design of all included studies was cross-sectional, so it was difficult to determine the causal relationship between internet use problems and emotional, personality, academic and interpersonal problems among left-behind children and adolescents. Fourthly, the included studies rarely discussed the differences in psychological problems caused by internet addiction in subgroups (gender, urban and rural areas, single parent or parent migration). Finally, publish bias was introduced due to the unavailability of databases, unpublished data, offline studies and papers published in languages other than English and Chinese.