The associations between screen time and mental health in adolescents: a systematic review

1Adolescence represents a phase of increased risk for the emergence of mental health problems. According to the 2021 update of the World Health Organization (WHO), it is estimated that 14% of young people between 10 and 19 years old have mental health problems, which represents, globally, 13% of all diseases that affect this population. Depression, anxiety, and behavioral disorders are among the leading causes of illness and disability in adolescents, and suicide is already the fourth leading cause of death among 15–19-year-olds.

2The current generation of teenagers is growing up immersed in a world saturated with electronic media, they did not know the times before the internet and for this reason, they are called “digital natives”. Media use of screen-based electronic devices is extensive, including television (TV) programs watching and using computers, tablets, and smartphones. In the last 10 years, the use of mobile Internet devices has increased exponentially, becoming part of everyday life.

3The increased use of screens has been noticeable and amplified in the COVID-19 pandemic due to isolation and restrictions on other leisure activities. The American Academy of Pediatrics (AAP) recommends that children over age five through adolescence be exposed to less than 2 h of screen time (ST) per day. However, a large percentage of adolescents already exceed this recommendation. In general, these media-related activities occupy about 6 to 9 h of a young American’s day, excluding housework and schoolwork.

4Adolescents are particularly susceptible to the opportunities and risks of new technologies. The development of socio-affective brain circuits can increase sensitivity to social information, impulsiveness toward rewards, as well as a preoccupation with peer evaluation. The growing suggestion that excessive screen time is related to recent increases in mental health problems among young people has been the focus of research. However, reviews of this nature were either restricted to children or included several age groups. In addition, the specific focus on a given symptom, or the concern with providing recommendations and strategies, reinforces the need for a more detailed investigation of this relationship among adolescents.

5Results from previous reviews are mixed. In the general population, research done during COVID-19 pandemic has found most evidence indicating negative effects of long screen time on mental health (MH). Among children, an association was found between screen time and internalizing and externalizing behavior problems. In adolescents, the association between social media use and psychological well-being was negative but very small. Together, adolescent children and young adults showed a small to very small association between screen time and depressive symptoms, varying between different devices and uses. Furthermore, methodological issues such as cross-sectional design, sampling and measurements can weaken the evidence.

6Accumulated evidence indicates that screen time may be associated with aspects of the adolescent’s mental health. However, the direction of these associations is not yet clear, the literature still lacks comprehensive and detailed research. With this in mind, this review aims to contribute to the understanding of the effects that exposure to screens can promote on a wide range of the mental health aspects of adolescents, which were previously researched such as flourishing (synonymous with a high level of mental well-being), life satisfaction, self-efficacy, self -concept Physical, psychosocial difficulties, conduct problems, hyperactivity/inattention and pro-social behavior, symptoms of internalization and externalization, positive mental health, and mental well-being. In addition, this review included the various screen-based devices most used by this population. The goal was to raise evidence that could increase knowledge about the interactions that adolescents set with screens, which may have potential additive increase in exposure time and effect on the mental health of this population.

7This review was conducted in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses – PRISMA and was registered at PROSPERO, under number CRD42022302817. A search was performed on 12/27/2021 with the following question: Is there any association between screen time and mental health in adolescents? For this, the following keywords were used: “screen time,” “adolescent,” and “mental health,” combined with the operator AND on databases PubMed, PsycINFO, and Scopus. An additional search was performed to update the research on 01/18/2023, using the same strategy and the same databases, totaling six more studies included. Table 1 presents the search strategies (Additional file 1: Table 1). The adopted strategy tried to increase the sensitivity of the searches, expanding the range of outcomes with the umbrella term mental health, and searching in all or any fields of the articles. In accordance with the PICO strategy, the study population will be composed of individuals in the adolescence phase and the intervention will be represented by exposure to screens. As outcomes, any aspects related to mental health will be considered, including measures related to mental well-being, like life satisfaction, and the control groups may be absent from the observational studies included. With the volume of data captured, considering previous reviews, the addition of records from the reference lists of the included articles was not considered.

8Inclusion criteria: (1) articles that directly assessed associations between screen time [i.e., the amount of time spent using a device with a screen such as a smartphone, computer or video game console (active screen, screens that allow motor interaction and responsivity), or television (TV) and videos (passives screens), for entertainment or educational use] and mental health, that is, (mood, internalization or externalization problems, sleep disorders, aspects related to mental well-being such as satisfaction with life, self-esteem and self-efficacy, among others), with at least one variable evaluated; (2) studies that measured mental health outcomes through validated scales/instruments; (3) studies with adolescents, average age between 12 and 18 years; (4) articles in English, published in the last 10 years. Exclusion criteria: (1) studies carried out with adolescents diagnosed with problematic internet use, (2) sample composed of adolescents already diagnosed with mental health problems or being followed up in mental health/psychiatry outpatient clinics, (3) research that used screen-based devices to aid functionality and (4) case reports and case series.

9The screening procedure was performed in pairs, including an initial independent search. After duplicate records were deleted, the titles and abstracts of each study were screened according to the inclusion and exclusion criteria. The articles eligible for full reading were selected and the two authors discussed the results and reached a consensus on articles to be included in the review. Any disagreements were resolved by consensus with the third author.

10The following data were extracted according to a standard form that included: first author, date, country of publication, study design, sample characteristics and study objectives, mental health assessment, measures of screen time exposure, and main associations found. The allocation of records in the form followed the year of publication, starting with more recent studies.

11The term self-reported was used to indicate that screen time was the time spent on screen-based activities, reported by the participant in response to a question. When the study applied a validated instrument or performed an objective measurement of screen time, it was indicated in the form.

12The methodological quality of the studies was assessed using the Newcastle-Ottawa Scale, based on criteria related to selection and comparability between cohorts and related to study outcomes. The methodological quality of the cross-sectional studies was performed using the adapted Newcastle Ottawa for cross-sectional studies. The evaluation was performed in pairs, by four reviewers and discrepancies were resolved by consensus with a fifth reviewer. The maximum score (9 points) represents high methodological quality.

13In the first search carried out on 12/27/2021, 1,309 records were identified in the database through the search strategy. Four hundred and forty-two duplicates were removed and 867 articles were screened by title and abstract. After screening, 763 reports were excluded because they did not meet pre-established criteria. Thus, 104 articles were reviewed, of which 44 were included in this review. These 44 articles were added to the most recent search, carried out on 01/18/2023, totaling 50 articles reviewed in this study. Both selection processes are described in detail in two PRISMA Flowcharts (Additional File 2: Figures 1 and 2).

14Of the 50 studies, published between 2011 and 2023, 38 were cross-sectional and 12 longitudinal, with a total of 1,900,447 adolescents. Table 2 (Additional file 1: Table 2) presents the distribution of this sample.

15Data extracted from the included studies are summarized in Table 1.

16Participants’ ages ranged from 10 to 21 years, mean 14,85 standard deviation 1,14. Some studies presented data on the age of participants based on school grade. In the pooled sample, there was a greater participation of girls, however, one study did not provide this data, and there was a study that evaluated only girls. Of the studies that reported sample demographic data, the socioeconomic status was mostly medium and predominantly white ethnicity.

17The measurements taken for both screen time and mental health were very heterogeneous. Most of the time, screen time was self-reported and aspects such as flourishing and resilience were considered in the mental health assessment. The data are described in detail in (Additional file 3).

18Most studies have observed associations between screen time and adolescent mental health. Only a few studies found no unfavorable associations between screen time and overall mental health, or any of its aspects. For the studies that found significant associations, most of the time, the findings were from just one survey, or congruent among a few studies, which did not allow performing a statistical analysis of the associations. A small number of studies showed an effect size from medium to large or large. Most made sizes were small, or medium.

19According to a study, with a robust sample of adolescents in the United Kingdom, the screen activities with the highest levels of engagement were social media, games and TV/video. Watching TV was positively associated with mood and anxiety disorders, impaired mental well-being, i.e., the more TV time, the higher scores for mood and anxiety disorders and greater impairment in mental well-being, and inversely associated with self-esteem and life satisfaction and psychological well-being for girls. Whereas in other studies, TV was negatively associated with anxiety, positively with mental well-being and lower prevalence of depression. Furthermore, one study did not find associations between watching TV and depressive symptoms, and another also found no associations with mental health.

20While Kim et al. (2020) did not find associations of active screen use with mood and anxiety disorders, and McAllister et al. (2021) between mental health and gaming, other studies did. A relationship was observed between computer use (such as for internet, email, and games) with impairment of mental well-being, psychological well-being and an increase in depressive symptoms. Video games alone were associated with more severe anxiety symptoms. And 6 h or more of video gaming was positively associated with anxiety symptoms in boys. Higher levels of computer use showed stronger association with depressive symptoms. And online gaming (among high school girls) was associated with a higher prevalence of depression. The studies do not specify the modality online or not of video gaming.

21The smartphone was the device that adolescents report more time using, according to Przybylski & Weinstein (2017). A recent study observed that telephone use showed a stronger association with depressive symptoms among the girls, while in another study it represented impairment of mental well-being only on weekdays. More time spent on new types of screen behavior, including social media, was associated with a higher prevalence of depression in one study. Social media use also had a median negative association with well-being in another study. Among girls, the positive association of mental health problems with social media and internet use was greater than for games and TV in the study by Twenge et al. (2021). In McAllister et al. (2021), media use negatively impacted mental health, but was not significantly associated with self-harm or depression among boys.

22Among adolescents with high recreational ST, about a quarter reported depressive symptoms in one study. Girls who reported ≥ 5 h of ST on weekdays or weekends had higher anxiety scores compared to those who reported up to 2 h, even controlling for moderate to vigorous physical activity (MVPA), in a recent survey. Time studying online was positively associated with anxiety in one study, but was not associated with mood disturbances in another, and in the latter, other ST uses were associated with mood disturbance.

23Young people who met screen time recommendations were about 2.6 times more likely to have good psychosocial health outcomes compared to those who did not in one study. Higher flourishing scores were associated with meeting ST guidelines of less than 2 h daily in one study. One study found that high ST (with < 8 h of sleep) was negatively associated with self-esteem, resilience, and flourishing.

24The study by Gireesh et al. (2018) also addressed well-being, finding greater screen time, and suffering from bullying associated with decreased well-being in both sexes, with the strongest association in girls. Playing electronic games was inversely associated with psychological well-being for adolescents of both sexes. Watching television was also inversely associated with psychological well-being in girls in one study.

25The association between the use of digital technology and adolescent well-being is negative, but small, representing less than 0.1% of the observed variability in well-being, according to the study by Orben and Przybylski (2019). Watching TV only on the weekend showed a median positive association with well-being. Social media use had a median negative association with well-being. In a previous study, Przybylski et al. (2017), observed a relationship with impaired mental well-being and watching movies/TV, playing games and using the computer throughout the week. As for smartphone use, this relationship was observed only on weekdays.

26Social media use was significantly correlated with depressive symptoms among girls but not among boys, moreover, all suicide-related outcomes were correlated with electronic device use in Twenge et al. (2018). In the study by Coyne et al. (2020), the increase in time spent on social media was not associated with an increase in mental health problems, when adolescents were examined at the individual level. In a recent study, more time spent in structured media activities, such as watching television, decreased levels of inattention and anxiety.

27An 11-year study found that increased TV viewing and Personal Computer (PC) use was predictive of conduct problems, hyperactivity, and inattention in girls. There was a small positive association between computer use at age 16 and anxiety and depression two years later in one study. Boy computer instrumental users had lower depression scores and fewer internalizing behavior problems than “e-gamers” in one study.

28In the study by Babic et al. (2017), decrease in total recreational screen ST was negatively associated with physical self-concept and psychological well-being, and there was a positive association between television/DVD use and psychological difficulties. CP time positively predicted emotional symptoms in one study. Girl instrumental computer users had higher self-efficacy compared to female computer e-gamers in one study.

29In a recent study, increased time spent on social media was the only screen media activity significantly associated with worse mental health. In another more recent study, the theoretical replacement of 60 min of television or social media use by team sports at age 14 years was associated with a reduction in emotional symptom scores at age 17 years, respectively.

30The summary of the methodological evaluation of the articles included in this review are presented in Table 4, according to the items of the Newcastle-Ottawa scale for observational studies, (Additional file 4: Table 4). The quality assessment of the cross-sectional studies was carried out by adapting the Newcastle Ottawa for cross-sectional studies. Most studies had high methodological quality, with a total score above 6. Recurrent problems among studies were the lack of a group not exposed to screens, generating comparability only between factors such as gender, in addition to the lack of objective measurement of screen time.

31Although screen-based activities bring many benefits, such as communication and entertainment, most of the results of this study indicate that excessive exposure to screens is associated with effects on the mental condition of adolescents. Of the 50 studies reviewed, only 12 found no unfavorable associations between screen time and overall mental health, or any of its aspects. It is also important to consider that some studies in this review were carried out during the COVID-19 pandemic and with social distancing, screen time may not significantly negatively interfere with well-being, since it is the only way to if you remain socially connected.

32The current review is consistent with other reviews that concluded that the type, use and content of the screen influences the relationship between mental health problems and ST. It seems that the impairment of mental health in adolescents is closely related to the purpose of screen use and not just the exposure time. For example, online study or non-recreational use of screens does not seem associated with mental health. Currently, there is a suggestion that the term “screen time” is no longer a useful construct, since the devices and the social character of the media must be evaluated separately, the nature of the content may be more relevant for mental health than the amount of time teenagers are exposed to screens. In fact, in this review, watching TV did not show a significant relationship with depressive symptoms, self-esteem or mental health, in some cross-sectional studies, it even decreased levels of inattention and anxiety longitudinally. It was also observed in the literature that, over time, the relationship between screen time and depressive symptoms varied between different screen uses, with stronger relationships observed with cell phones and computer/internet, new forms of technology.

33A very popular activity among teenagers is the use of social media such as Facebook, Instagram, and Twitter. Here, social media use was associated with poor mental health and impaired mental well-being. Our results involving social media agree with previously published reviews. In fact, excessive use of social media can lead to the development of fear of missing out (FoMO). FoMO is defined by the fear that other people will have pleasurable experiences while the individual is away, felt as a need for constant contact with members of the social network. It is true that in adolescence internalizing symptoms happens frequently and here these symptoms were the most common. Thus, the association between social media use and internalizing symptoms may be complex. Social media can worsen depression and anxiety, however, adolescents having depression and anxiety symptoms may lean on technology to alleviate those feelings too. In this sense, our results and other revised longitudinal data agreed, that a stronger relationship was observed between greater exposure to screens and a subsequent increase in the depression score.

34Regarding games, the results were mixed, in McAllister et al. (2021) associations with mental health were not significant for boys and girls. Boers et al. (2019) also did not find a significant association between the time spent playing video games with depression, these authors consider that video game players are not socially isolated, they play with friends, physically or online, which it has social and emotional benefits. However, few studies had already observed a significant association between playing video games and worse mental health in adolescents.

35In this review, non-recreational computer use for girls was associated with greater self-efficacy, while boys had lower depression scores and internalizing behaviors than those who used their computers only as a game console (“e-gamers”). The authors suggest that adolescents were acquiring more computer skills, which had already been associated with improved mental well-being in a previous study. In this sense, our data are confirmed in studies over time in which depression did not increase at the intrapersonal level.

36Smartphone and social media use has been associated with depression and internalizing symptoms. Twenge in 2017 already raised the concern on whether smartphones were “destroying a generation”. Odgers (2018), however, concluded that this would be a misinterpretation of reality, as most adolescents are doing well in the digital age and that US and European numbers show academic improvement, a decrease in violence, abuse of alcohol, smoking, and teenage pregnancy. Smartphone studies can have limitations, such as an often underestimate smartphone use, leading to low correlations between self-reported screen time data and data collected through the device app itself. Considering screen time simply by counting frequency and duration may limit understanding of an adolescent’s relationship with the smartphone and the consequences on mental well-being. It would be important to obtain detailed information about the goals and how the adolescent uses their device.

37In one study, significant associations between anxiety and depression appeared when screen time was combined with shorter sleep duration. It is not yet established whether the act of looking at the screen interrupts sleep or whether the media content is responsible. Light-emitting diode (LED) screens on computers and phones emit a slow wave, blue light, which can interfere with the circadian rhythms that regulate sleep. Exposure to LED versus non-LED screens produces changes in melatonin levels and sleep quality, and this exposure decreases cognitive performance. Sleep disturbances may also be related to excessive use of technological devices at night. Sleep disorders is an umbrella term, according to the International Classification of Diseases 11th Revision (ICD-11), they belong to an overlapping area between mental health and neurological disorders, and according to WHO they are part of common mental health disorders. Sleep disorders are often associated with depression and anxiety and often co-occur or even antecede the disorders diagnosis. Currently, young people interact on social networks, sending messages and selfies, sometimes all night, a characteristic behavior that gave rise to the term “Vamping”. This term relates to tech-addicted teens who already have a disrupted circadian rhythm and who are at greater risk of declining school performance and loss of self-control. In fact, in another study of this review, self-esteem, resilience and flourishing were negatively associated with ST in those adolescents who slept less than eight hours a night.

38In addition to sleep, physical activity may also protect against the potentially harmful effect of interacting with social media in some adolescents. From the records reviewed, some studies noted that replacing screen time with physical activity showed a positive effect on associations with mental health. Insufficient physical activity and high ST was associated with increased psychosocial difficulties. In fact, a review that investigated moderating variables of associations between ST and depression in youth found that physical activity can influence the magnitude of these associations.

39Increased screen time was significantly associated with aspects of mental health. Few studies showed an effect size from medium to large or large (21,24,34,60). However, most studies observe small effect sizes, or medium. Our findings are agreed with previous literature about the predominant small effect size, in addition to the large heterogeneity of the studies.

40The results of this review suggest that interaction with screen-based devices may underlie the impairment of adolescent mental health over the last decade. However, other studies also agree that establishing causality and directionality can be difficult. While research is still being conducted, care must be taken in interpreting data on the positive and negative effects of adolescents’ interaction with digital technologies. However, even with possible benefits, it may not be healthy to suppress the other activities that our nature is qualified for, underutilizing our other senses, and looking at screens for most of the day.

41This study contributes with data on the various mental health outcomes of adolescents, including aspects of positive mental health, in addition to considering exposure to all types of screens most used by this population. This review found some evidence for the current research question, we highlight here that watching TV for 2 to 4 h on school days was negatively associated with anxiety and self-esteem. The most time spent by adolescents was with the smartphone and use during the week was associated with diminished mental well-being. Screen exposure time was most positively associated with problems in teens’ mental well-being. Social media use had a median negative association with mental well-being in adolescents and an increased risk of depression in girls. Furthermore, “screen time” may no longer be appropriate for investigations of the effects of exposure to screen-based devices and related mental health outcomes in adolescents. Most of the reviewed studies provided total measures of time spent in front of screens, however, the nature of the content offered on each device, as well as the interaction of adolescents with this content, is still unclear.

42More detailed studies will be needed, seeking to understand the motivations of adolescents to engage with screen devices. Studies that consider issues related to the environment of adolescents may also help to clarify the varied emotional responses to screen stimuli. Longitudinal studies that pay attention to factors such as sleep, physical activity and socioeconomic status will also be important to establish mediators of associations between interaction with screens and mental health in this population.

43The current review has some limitations, which may impact the generalizability of the results. The first refers to the diversity and fragility of the methods applied in the data collection of the included studies. Self-reported screen time may provide inaccurate data due to adolescents’ recall difficulties. Studies focusing on sedentary behavior that included screen time in this category may provide even coarser measures of this variable. The lack of measurement of adolescents’ interaction time with each type of device and type of content leads to a superficial assessment of the associations between screen time and adolescents’ mental well-being, especially considering the emotional particularities of this phase. The wide variety of instruments to assess mental health outcomes can also be a factor that makes it difficult to standardize results. The second limitation is related to studies that analyzed data from previous research. These studies, in addition to addressing many variables not reviewed in the present study, used old data with a reality different from that observed today. In addition, of the articles reviewed, only one study from Brazil and five from Australia represented the global south, it is necessary to increase diversity. And finally, as adolescents’ interactions with screens and their contents can vary depending on when they occur and for what purpose the screens are being used, the associations between screen time and mental health depend on intensity and context, such as the day of screen use in a week, for the purpose of use and whether the use is recreational or for study.

44Below is the link to the electronic supplementary material.