Risk factors for problematic smartphone use in children and adolescents: a review of existing literature

In recent years, the worldwide percentage of smartphone owners and users has increased steadily [ 1]. With features including, among others, communication, Internet, and multimedia [ 2], smartphones—not least because of their ease of access [ 3]—have several advantages such as productivity enhancement, facilitated information seeking [ 3], and heightened pleasure via social interactions [ 4].

Despite these benefits, however, a growing body of literature hints at negative consequences and possible dangers associated with smartphones [ 3, 5, 6]. These include excessive use [ 3], increasingly uncontrollable behaviors such as constantly checking for notifications [ 4], mental health problems such as depression and anxiety [ 3, 7], and physical problems [ 8]. It has been argued that problematic smartphone use can be viewed as a form of behavioral addiction like gaming addiction or Internet addiction [ 2, 4, 9]. Symptoms commonly associated with behavioral addictions, such as tolerance, withdrawal, mood dysregulation, cravings, and loss of control, have also been found to be related to problematic smartphone use [ 10]. Based on these findings, and similar to Internet addiction, Demirci et al. [ 2] have suggested that smartphone addiction is characterized by an overuse of smartphones that interferes with the users’ daily functioning.

Nevertheless, smartphone addiction is included neither in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) [ 11] nor in the upcoming International Classification of Diseases 11th Revision (ICD-11) [ 12], although the DSM‑5 now lists diagnostic criteria for Internet gaming addiction with the need for further research [ 11], and the ICD-11 has included the diagnosis of (Internet) gaming disorder in its preliminary online version [ 12]. On the one hand, this is interpreted as an increasing awareness concerning the existence of smartphone addiction by some [ 9]. On the other hand, a recent review [ 6] concludes that, to date, evidence is not sufficient to support the existence of smartphone addiction.

Instead, the authors suggest the terms problematic or maladaptive smartphone use, which pertain to an excessive behavior with lower levels of impairment than addiction [ 6]. Excessive use is sometimes measured as duration of usage and usage frequency (e.g., see Bae [ 13]), and problematic use is considered an uncontrolled behavior leading to negative consequences in everyday life [ 14]. The terms problematic smartphone use and smartphone addiction seem to be used synonymously, based on the researchersʼ understanding of the underlying construct. Researchers who assume the observed behaviors meet addiction criteria seem to choose the term smartphone addiction (e.g., see Yen et al. [ 15]), whereas researchers who do not consider addiction criteria met choose to refer to problematic smartphone use [ 3, 6, 14].

Given this inconclusive terminology, synthesizing existing research regarding problematic smartphone use in children and adolescents is a challenge [ 16]. For instance, reported prevalence rates of children and adolescents with problematic smartphone use vary widely, from 5% [ 17] to about 50% [ 15]. This may be interpreted mainly as a result of the different operationalizations used in different studies. These include, among others, problematic phone use [ 15, 17], extensive use of mobile phones (e.g., see Sánchez-Martínez and Otero [ 18]), smartphone addiction risk (e.g., see Lee et al. [ 5] and Cha and Seo [ 9]), and smartphone addiction [ 19– 21].

Similarly, research on risk factors for problematic smartphone use in children and adolescents has, to date, yielded inconclusive results. Overall, minors seem to be particularly vulnerable [ 5, 9], which could be related to difficulties in self-regulation [ 4] and immature control competencies [ 22]. Other factors possibly influencing maladaptive usage in children and adolescents include age [ 23– 25], gender [ 10, 24, 25], social factors [ 24, 26], and personality [ 23, 25, 27, 28].

Despite the growing body of data, comprehensive reviews synthesizing key findings are still scarce. A meta-analysis [ 20] focuses only on India, and Park and Park [ 24] propose a model of smartphone addiction but without comparing different results and without considering age groups other than early childhood. Furthermore, as smartphone technology is advancing rapidly, new developments have arisen since 2014. Hence, a review focusing solely on mobile phone addiction seems to fall short. Therefore, this review sets out to provide an overview of studies on problematic or addictive smartphone use in children and adolescents, with the focus particularly on factors that increase the risk of problematic smartphone use.

Although research regarding problematic smartphone use in children and adolescents covers many potential risk factors, the results are somewhat conflicting. Several aspects might have contributed to these contradictory results.

First, constructs examined by different questionnaires were not the same. The most frequently applied measure [ 10, 27, 28, 31, 37, 42, 49, 55, 58] was the Smartphone Addiction Scale (SAS–SV [ 10]). With eight studies referencing it [ 5, 9, 21, 31, 44, 46– 48], the Smartphone Addiction Proneness Scale (SAPS [ 30, 70]) was the second most frequently applied assessment. Both measures assess the construct of smartphone addiction. Other measures pertained to the operationalization “mobile phone use.” Additionally, unrelated measures were adapted by authors for the purposes of their studies (e.g., see Young [ 33, Kwak et al. 43, and Jeong et al. 45]). The use of such a wide range of questionnaires is merely a symptom of a field of research that has yet to define its key research subject. Hence, operationalizations between questionnaires differ, and in many cases the term “cell phone” is simply substituted with the term “smartphones” [ 30]. In sum, most studies refer to smartphone addiction, whereas the term “problematic use” seems to be prevalent particularly in studies referencing mobile phones or cell phones. These heterogeneous operationalizations may again be understood as a reflection of the lack of a clear and concise conceptualization of the phenomenon. Hence, the need to reach a mutually accepted comprehensive definition of problematic smartphone use is a conditio sine qua non for further progress in the field.

Second, while the time frame (2008–2019) for the search was deliberately chosen so that the probability of including papers that focus on smartphones was increased, it is possible that participants were indeed using mobile phones without Internet access. It is not always clear which type of phone is referenced in studies and which specific features these phones had. This may substantially bias the conclusions drawn here. For example, time spent online [ 16] and on SNS [ 5, 9, 21, 46] has been identified as a possible predictor for smartphone addiction, yet in phones without Internet access, problematic usage is automatically precluded. Upcoming studies should therefore pay attention to precisely describing the type of phones studied as well as their available and actually used functionalities.

Third, all the studies included in this review focused on adolescents or mixed samples, whereas studies on young children (aged 1–10 years) are considerably scarcer. This is due to a higher prevalence of use and ownership of smartphones in adolescents. Yet in the past years, smartphone usage rates have also considerably increased among preschool children aged 6–10 years (see [ 71]). Hence, future research should include younger samples, as well as make an effort to not only focus on the role of parents in mediating media use, as done by those studies including younger children (e.g., see Hwang et al. [ 72]), but to assess child experiences directly.

It may be noticed that most studies (42.1%) that met criteria for inclusion came from South Korea. In comparison to other nations, ownership of smartphones has been found to be highest in South Korea [ 73], and about 96% of adolescents from South Korea use a smartphone [ 9]. Furthermore, studies suggest that cultural factors such as individualism vs. collectivism may have a significant influence on technology usage and technology acceptance in general [ 74] as well as on Internet addiction in particular [ 75]. For instance, a study evaluating the underlying factor structure of the Internet Addiction Test (IAT) in three collectivistic and individualistic cultures (United States, China, Africa) found the psychometric constructs to differ significantly across cultural, economic, and technological contexts [ 75]. Translated to the context of problematic smartphone usage, it is likely that the instruments used to assess addiction levels may have also overestimated or underestimated addiction rates as they may not have been designed to appropriately capture culturally shaped behaviors associated with smartphone use (e.g., whether smartphones are used more for mood modification in one culture than another; see Chen and Nath [ 75]). A more careful consideration of cultural factors in future research is needed to add to a better understanding of the generalizability and validity of the construct of smartphone addiction across cultural contexts.

Among possible predictors of problematic smartphone use, most factors produced contradictory findings. While a longer duration of use seems to be quite clearly associated with higher addiction scores, research on risk factors such as gender, social networks, and patterns of use remains inconclusive. Regarding age, findings suggest positive as well as negative correlations with smartphone addiction. Some findings exist about the influence of the school environment, as well as of family and personality factors, but corresponding data are still scarce.

Regarding gender, more studies seem to support the conclusion that female adolescents are more prone to a higher smartphone addiction risk than male adolescents. This is in line with a study in adults by van Deursen et al. [ 4], who also found a higher risk for smartphone addiction in women than in men. The authors relate this to the finding that women experience more social stress than men and that this results in gender-specific use patterns. Correspondingly, it has been shown that girls use their smartphones to a higher extent for social reasons than boys do [ 5, 27, 43, 47]. Boys, in turn, seem to focus more on gaming and media data sharing [ 27].

These differing usage patterns again fuel the debate about the conceptual validity of the construct at hand. One is inclined to argue that smartphone addiction, as it is currently defined (e.g., see Cha and Seo [ 9] and Kim et al. [ 30]), might be too broadly conceptualized. Similar to the dispute on whether the phenomenon of “Internet addiction” exists (e.g., see Widyanto and Griffiths [ 76]), it is conceivable that smartphone users may not be addicted to the device itself but to the applications provided by it (e.g., SNS, online games, online pornography). Thus, in correspondence to the suggestion made by Griffiths [ 77], a distinction needs to be made between addictions to the smartphone and addictions on the smartphone. It may, thus, be more promising to focus on specific types of use (e.g., problematic gaming as proposed by the ICD-11 [ 12]) in future research and assess relevant indicators of behavioral addictions (e.g., salience, mood modification, tolerance, withdrawal, conflict, and relapse [ 76]) in relation to specific applications rather than merely considering the frequency or duration of using the technical device in general.

One of the limitations of this review is that the causality of the relation described for the variables in question is not statistically firm across all studies. Most studies included here used correlational research and were cross-sectional. Yet in order to debunk the question of directionality (i.e., whether a postulated risk factor is a contributor or a consequence), longitudinal research is warranted.

Despite interpretational difficulties due to different operationalizations, this review was able to provide an overview of risk factors related to problematic smartphone use or smartphone addiction in children and adolescents. Based on this, the following implications for future research may be postulated: Most importantly, a concise definition of the construct with a standardized terminology and operationalization would enhance the comparability of findings. Developing a comprehensive theoretical framework for this construct is, however, closely related to the question of whether it constitutes a singular entity that is sufficiently distinct from other concepts such as problematic gaming, or whether it is merely a symptom of the latter or of the addiction to specific applications on the smartphone.