Internet Addiction in Adolescents: A Review
Tiffany Martini
Field*
Touch Research Institutes,
University of Miami/Miller School of Medicine, Miami, Florida, USA
*Corresponding author: Tiffany
Martini Field, Touch Research Institutes, University of Miami/Miller School of
Medicine, Miami, Florida, USA. Tel: +13052436781; +13052436790; Email: tfield@med.miami.edu
1. Internet
Addiction in Adolescents: A Review
One of the first
papers on the negative effects of excessive internet use on adolescents’
relationships with their parents and peers was published 18 years ago [1].
At that time, the term internet addiction was rarely used and very few papers
on that topic appeared in the literature. Since then, hundreds of studies,
mostly survey studies, have been conducted around the world. For this review, a
literature search was conducted on PubMed and PsycInfo for the years 2014-2017.
Exclusion criteria included non-English papers, case studies, under-powered
samples and non-juried papers. Although most of the adolescent internet
addiction papers during the last few years have focused on risk factors and
negative effects of excessive Internet use by adolescents, this review also
includes brief summaries on the measures, prevalence and types of internet use
as well as the very few studies on interventions.
The signs and symptoms
of Internet addiction include compulsive use, withdrawal, tolerance, and
adverse consequences [2]. Of the papers reviewed here, approximately a
third have used the term Internet addiction, another third have referred to it
as problematic Internet use and the final third is distributed across a variety
of terms including pathological internet use, excessive internet use, intensive
internet use, compulsive internet use, internet dependence, internet addiction
disorder, heavy Internet use, high-risk users and internet abuse. This variety
of terms reflects the diversity of studies across multiple countries and the
relative lack of consensus about how to define internet use. Although some
investigators have simply used “greater than two hours per day of internet use
for activities other than work or homework” to define internet addiction, most
have used a variety of scales, i.e. some 21 instruments that have been
developed or adapted as abbreviated scales or as culturally relevant measures.
2. Measures,
Prevalence and Types of Internet Use
The Internet Addiction
Test (IAT) developed by Young in 1995 is among the most popularly used measures
of internet addiction in adolescents. This 20-item scale includes questions
like “How often do you try to hide how long you’ve been on-line?”,” How often
do you choose to spend more time on-line over going out with others?” and “How
often do you feel depressed, moody or nervous when you are off-line, which goes
away once you are back on-line?“ Shorter scales including the abbreviated
version of the Problematic Internet Use Questionnaire (PIUQ) (6
items) [3] and the Problematic and Risky Internet Use Screening Scale
(PRIUSS) (3 items) [4] have also been used in the recent literature
on the prevalence of Internet addiction in adolescents. The 3-item scale is
comprised of items on anxiety when away from the internet, loss of motivation
when on the internet and feelings of withdrawal away from the internet.
However, the authors suggest that positive screens on the 3-item version should
then be followed by the use of the 18-item PRUISS.
The prevalence of
internet addiction in adolescents has varied significantly depending on the
measure used and the country of the research group. For example, the prevalence
in a sample of 720 Turkish students on the internet Addiction Scale was 7% (71%
men and 29% women) [5]. In another Turkish sample on 271 students using
the same scale, the prevalence was 3 times that rate (20%) [6],
highlighting the variability of prevalence data. In a sample of 5,005 European
adolescents 14% were above the cut off for problematic internet use based on
the short (6-item) PIUQ [3]. In a larger sample of 7,351 European
adolescents a similar percentage (13%) of adolescents spent more than 20 hours
per week on the internet and had high scores on the PIU. A comparison between
two different time periods in 5 European countries (Estonia, Germany, Italy,
Romania and Spain) showed a 4-7% increase over a two-year period in
pathological internet use [7]. Some have argued that heavy use over time
should be used as the criterion for internet addiction instead of the
self-report scales, but a French survey on 22,945 French and Swiss adolescents
suggested that use over time was moderately correlated with scores on internet
addiction scales [8].
Culturally appropriate
adaptations of the IAT have yielded higher percentages of use. For example, a
screening on a sample of 5,366 adolescents from six Asian countries (China,
Hong Kong, Japan, South Korea, Malaysia and the Philippines) revealed the highest
rate of addiction in the Philippines but only a 5% rate when using the IAT and
4 times that rate when using the Chen Internet Addiction
Scale-Revised [9]. The greatest prevalence noted in this literature search
was in a sample of 408 Iranian students in which as many as 41% of students had
internet addiction based on the IAT [10]. This far exceeds the
international average of 15% [11]. Reputedly, pathological internet use
occurs more frequently in adolescents than adults and is on the increase in
several industrial countries, especially in Asia, North America and
Europe [12].
The types of Internet
use have varied as a function of demographic variables, for example, gender of
user. In a sample of 967 Spanish adolescents, the most frequently used apps
included WhatsApp (77%), social networks (70%) and music apps (67%) [13].
The most common use for girls was social networks, WhatsApp, Instagram and
listening to music. In contrast, the teenage boys most frequently used the
internet to browse the web, Skype, play and watch movies or tv shows. Similar
gender differences were noted by another group of researchers including boys
spending more time gaming and girls spending more time chatting on the social
network [14]. Different motives for internet use have also been studied in
a sample of 101 German adolescents [11]. Based on the Internet Motive
Questionnaire for Adolescents (IMQ-A) that assesses social, enhancement, coping
and conformity motives, half of the students were high-risk internet users.
Although this sample of adolescents primarily used the internet for social
motives followed by enhancement and coping motives, the high-risk users
accessed the internet more often for coping and enhancement and the low-risk
users for social reasons.
3. Risk
Factors
The classification of
risk factors or predictor variables is arbitrary in as much as many of the
studies on internet addiction in adolescents are correlational and the
direction of effects cannot be determined. Although the risk factors are often
presented as predictor variables especially in regression and structural
equations analysis models, they may also be effects variables, as causality
cannot be established. Risk factors can be more clearly noted in longitudinal
studies.
However, very few of
those appear in this literature that generally features large sample, survey
studies that would not lend themselves to follow-up assessments. In the
2014-2017 literature reviewed here, risk factors/predictor variables for
Internet addiction can be categorized as demographic variables, parent
characteristics, personality traits, psychological problems and multivariate
studies that include multiple problems. Demographic variables include gender
and age. Parent variables include parent use of the internet, depression and
heritability. Personality traits include self-esteem, self-regulation,
perfectionism, empathy, consciousness. Psychological problems that have been
related to internet addiction in adolescents include ADHD, neuroticism,
anxiety, and depression. The multiple problems studies have typically featured
comorbid psychological problems, childhood experiences, academic performance
and family relationships.
Demographic variables.
In a survey study in the Netherlands, 474 adolescents completed the Problematic
and Risky Internet Use Screening Scale [15]. The authors were interested
in Problematic Internet Use (PIU) which they defined as internet use that is
risky, excessive or impulsive in nature and leads to adverse life consequences.
The survey revealed that 11% of the adolescents were at risk for PIU and that
risk was significantly associated with male gender, increased age and posting
on a Social Networking Site (SNS) more than four times a day. However, it was
not associated with the number of SNS profiles, SNS preference or the number of
online friends. Male gender as a risk factor also emerged in a study on Hong
Kong adolescents where the prevalence rates ranged from 17 to 27% [16].
The male adolescents not only had a higher prevalence rate but more internet addictive
behaviors than the females. Female students had more problematic internet use
in at least one study from Spain [17], and, no gender differences were
noted in a study on Turkish students [6].
The usual problems of
correlation studies apply to these demographic studies including the lack of
control over confounding variables. Regression and structural equations
analysis models could have been used in these large sample studies to control
for potentially confounding variables and to determine the relative
contribution of these variables to the outcome variance on internet addiction
in adolescents.
Parent variables. In
the literature on parent variables more inferences can be made based on the
more robust regression analyses used. Parent variables in this literature
search included parent internet use, lack of control, depression and
heritability. In a survey on parent internet use, a random sampling of 1,098
parents and their adolescents suggested that 24% of adolescents and 6% of
parents could be classified as moderate to severe problematic users of the
internet [18]. In their stratified regression analysis, parent problematic
internet use was related to adolescent problematic internet use. In a thematic
analysis on Australian parents’ perceptions of their adolescents’ use of the
internet, two themes emerged suggesting the parents’ sense of loss of control
over the family environment and an inability to protect their adolescents from
material on the internet [19]. Using logistic regression modelling techniques,
a significant association has been noted between moderate to severe depression
in the parents and internet addiction in their adolescents (as measured by the
Internet Addiction Test) after controlling potential confounding
variables [20].
In a heritability
study, the Compulsive Internet Use Scale (CIUS) was given to 5,247 monozygotic
and dizygotic adolescent twins in the Netherlands [14]. The heritability
estimate suggested that 48% of individual differences in the scores could be
explained by genetic factors and there were no gender differences on the
heritability estimates. While the data from these studies are suggestive, it is
unfortunate that the separate studies focused on single variables rather than
exploring the group of parent variables in a multivariate study. Conceivably
the other measures collected on these very large samples will be presented in
future publications.
Personality traits.
Self-esteem has been a factor in at least two studies on internet addiction in
adolescents. In a regression analysis on data from 408 Iranian students,
depression and self-esteem contributed to the variance in internet
addiction [10]. In a Chinese study on 911 adolescents, self-esteem and
social support were negatively correlated with internet dependence [21].
In this case, social support mediated the relationship between self-esteem and
internet dependence. When self-esteem, self-control and well-being have been
measured along with problematic internet use, lower levels of each of these
variables were predictive of problematic internet net use in a sample of 1552
Chinese adolescents [22].
Other personality
traits that have been related to problematic internet use include self -
regulation, perfectionistic attitude, empathy and conscientiousness. In a
longitudinal study on 801 Spanish adolescents, structural equation modeling
revealed that deficient self-regulation at time one predicted an increase in
preference for online interactions, mood regulation and negative consequences
of the internet at time two (components of problematic internet use) [23].
Problematic internet use at time one predicted an increase in problematic
alcohol use at time 2. In a multiple binary logistic regression analysis on a
data set from 720 students, male gender, duration of internet usage, depression
and perfectionistic attitude were predictors of internet addiction [5].
Perfectionistic attitude was a predictor of internet addiction when gender,
depression and duration of internet use were controlled. Lower empathy has also
been associated with greater problematic internet use in samples from both
China (N=438) and Germany (N=202) [24]. Low conscientiousness has been a
predictive factor in at least two studies. In a sample of German adolescents
(N=1489), lower conscientiousness was a significant predictor variable for
problematic internet use [25]. In a larger sample of German adolescents
(N=9,293) low conscientiousness was a significant predictor of internet
addiction in both boys and girls [26].
Psychological
problems. Psychological problems that appeared in the literature review (2014 -
2017) on internet addiction in adolescents included neuroticism, anxiety, depression,
and ADHD. In at least two studies neuroticism has been a significant predictor
of problematic internet use. In one of these studies, neuroticism was measured
by the Big Five Inventory (N=1489) [25]. In the other study, neuroticism
was measured by the Eysenck Personality Questionnaire (N=1211) [27]. In
this study, the high use adolescents were also less extraverted.
Anxiety has been a
predictive factor in at least two studies. In one of these, higher levels of
anxiety were associated with internet addiction, although this association was
weakened in classrooms which featured higher levels of extraversion [28].
More specifically, social anxiety disorder has been related to internet
addiction and the hikikomori phenomenon (extreme retreat to one’s own room) by
another group [29]. In a recent review, however, mixed findings have been
reported for the association between social anxiety and problematic internet
use [30].
Depression has also
been noted in several studies on problematic internet use in adolescents. While
one study suggested that anxiety “triggered” internet use in boys, girls’
internet use was triggered by depression (N=1468 Spanish speaking,
Latin-American adolescents) [31]. In a logistic regression analysis of
adolescent data from Taiwan (N=2170 senior high school students), depressive
symptoms was a significant predictor variable [32]. In a study on 600
Italian students, those with high levels of depression had higher scores on
internet addiction severity [33]. In a study on Turkish adolescents with
major depression disorder, the rates of problematic internet use were higher
than in adolescents who did not have major depression disorder [34]. These
findings were consistent with a longitudinal study showing that depressive
symptoms at time one predicted increased preference for online relationships
and mood regulation problems at time two after one year [35]. These
relationships between depression and components of problematic internet use are
perhaps more compelling as they come from a longitudinal study.
Depression has been a
mediator between social support and internet addiction in at least one study on
10,158 Chinese adolescents [36]. In this research, 10% of the sample were
moderately addicted based on the Youth Internet Addiction Test. Although other
factors were considered including parental control, household income, academic
performance, access to the internet and online activities, the multivariate
logistic regression analysis showed that social support had a significant
negative effect on internet addiction with depression mediating that effect.
Anhedonia, a key facet of depression that is defined as difficulty experiencing
pleasure, has predicted greater levels of compulsive internet use in a
longitudinal study with a one-year follow-up assessment [37]. And,
rumination, another factor associated with depression, has also been predictive
of addictive internet use [38].
Attention deficit
hyperactivity disorder (ADHD) comorbid with depression has also been a risk
factor for problematic internet use [30]. In this review, strong
associations were reported for these three problems. As these authors
suggested, mental health problems have led to excessive internet use, but few
studies have explored the alternative direction of problematic internet use
leading to psychological problems. In another review of the literature using
four online databases (CENTRAL, EMBASE, PubMed and PsycINFO) 15 studies met
inclusion criteria and were included in a meta-analysis [39]. A moderate
association was found between ADHD and internet addiction.
Thus, several
psychological problems have been significantly associated with internet
addiction. Typically, these have been explored in large sample survey studies
based on questionnaires and regression or structural equations analyses have
been performed with the psychological problems as predictor variables for
internet addiction. Entering internet addiction as a predictor variable for the
psychological problems is less frequent in this literature. Because most of these
studies are cross-sectional rather than longitudinal, causality in either
direction cannot be determined.
Multivariable risk
studies. Several multivariate studies have been conducted. Unfortunately, many
of them performed correlation analyses, making it difficult to determine the
relative importance of the variables as risk factors. Nonetheless, they
highlight multifactorial risks for internet addiction in adolescents. Some of
these studies focused on comorbid psychological problems while others focused on
internet addiction comorbid with other forms of addiction.
Emotional problems and
their relationships to pathological internet use symptoms were explored in a
rare longitudinal study with a two-year interval [40]. In this European
study, based on the Internet Addiction Test, previous pathological internet use
symptoms and emotional problems were significant predictors of pathological
internet use two years later. Surprisingly, emotional problems predicted
pathological internet use above and beyond the influence of previous
problematic internet use.
In a Turkish study in
which 59% of the 271 students had mild internet addiction scores (39%) or high
internet addiction scores (20%), correlation analyses revealed that the
severity of internet addiction was correlated with borderline personality
features, emotional abuse, depression and anxiety symptoms [6]. In another
Turkish sample (N=468) a different group of investigators reported significant
correlations between internet addiction and depression, anxiety, attention
disorder and hyperactivity symptoms as well as smoking [41]. Internet
addiction was not correlated with age, gender, body mass index or family
income.
Problematic internet
use was noted in 14% of a sample of 5,538 adolescents from Barcelona Spain and
was associated with female students, smoking, drinking, marijuana or other
drugs, poor academic performance and poor family
relationships [17]. Elevated dopamine was a potential underlying
mechanism for the multiple addictions shown in this study. In at least one
study dopamine levels were elevated in adolescents with high scores versus
those with low scores on the Internet Addiction Test, and dopamine levels were
correlated with weekly online time, although they were not correlated with the
duration of internet use [42]. The results of a binary logistic regression
analysis suggested that dopamine levels and weekly online time contributed to a
significant amount of the variance on internet addiction scores. These data are
perhaps not surprising in that dopaminergic areas of the brain light up during
pleasurable experiences and during addictive activities.
Relationships have
also been noted between internet addiction and personal relationships and
academic performance. In a study on Chinese adolescents (N=755), internet
addiction prevalence was 6%, and logistic regression analyses revealed
significant associations between internet addiction and interpersonal problems,
school-related problems and anxiety symptoms after controlling for demographic
characteristics [43]. In a European sample (N=1,444), pathological
internet use was noted in 5%, while 15% made cut-off criteria for risky
Internet use [44]. Pathological internet use in this sample was related to
the termination of a romantic relationship as well as non-optimal academic
performance. As in several of these correlation studies, the direction of
effects is not known. The latter problems could have led to the pathological
internet use or vice versa.
Even more serious
problems have been associated with internet addiction including aggression and
cyberbullying. Surprisingly, these problems have rarely been noted in the
recent literature on internet addiction in adolescents perhaps because there is
a separate literature on cyberbullying, just as there is a separate literature
on cell phone addiction. Cyberbullying smoking, alcohol and depression were
related to internet addiction in a sample of 1,808 Junior high school students
in Taiwan [45]. In a Korean study in which internet overuse was noted in
as many as 40% of middle school students, relationships were reported between
overuse and attention problems, gender, delinquent behaviors and depressive
symptoms, age and aggressive behavior [46]. These authors also reported
that the age of initial internet use was negatively correlated with internet
addiction and implied that the emotional and behavioral problems of these
adolescents preceded their internet addiction.
4. Negative
Effects of Internet Addiction on Adolescents
This section is
entitled negative effects inasmuch as no positive effects were noted in the
recent literature on adolescent internet addiction. Effects that were found
could be categorized as physiological including blood pressure, evoked
potentials, fMRI, sleep and overweight data. Psychological variables that
appeared as negative effects of internet addiction included depression and
suicidal ideation. Behavioral effects included school burnout and inferior
academic performance. Relationships with parents were also negatively affected.
Several internet addiction studies suggested negative effects that included
risk-taking, sexual behavior, smoking, alcohol and drug use. Although, again,
most of these studies are cross-sectional as opposed to longitudinal, suggesting
that causality cannot be implied and that these are not necessarily negative
effects but might also be risk factors.
Physiological effects.
Physiological effects noted in the recent literature on internet addiction in
adolescents include blood pressure, evoked potentials, fMRIs, sleep and
overweight variables. In a study on the relationship between blood pressure and
internet use, heavy internet use was defined as more than two hours per day and
more than five days a week and elevated blood pressure was defined as systolic
or diastolic blood pressure above the 90th percentile [47]. Heavy internet
users had more elevated blood pressure as compared to light internet users.
Adolescents with problematic internet use have also shown decreased sensitivity
as indicated by event-related potentials to both negative and positive feedback
during a risk-taking task [48]. In a review on 18 fMRI studies (17 of them
from Asia), less than half of the papers reported behavioral differences
between internet addiction disorder youth and normal controls [49].
However, all of the studies noted significant differences in cortical and
subcortical brain regions involved in cognitive control and reward processing,
suggesting that internet addiction may seriously affect brain functions. In a
study on male adolescents with internet addiction, fMRIs showed significantly
decreased functional brain connectivity and cortical thickness in the right
lateral orbitofrontal cortex, suggesting this may be a neurobiological marker
of internet addiction.
At least 4 studies
have reported associations between internet addiction and sleep problems. In a
cross-sectional study of 3,067 eighth-graders living in Switzerland, internet
use was associated with several pain syndromes including back pain and
musculoskeletal pain as well as overweight and sleep problems [50]. When
the data were entered into logistic regressions, only sleep problems remained
significant. Problematic internet use has also been related to sleep
disturbance in a sample of 1,772 Chinese adolescents in which 17% met the
criteria for problematic internet use based on the Chinese version of the
Internet Addiction Test [51]. And males in a sample of 7,533 German
adolescents who used internet more than 3 hours a day reported insomnia
complaints [52]. In another study that used internet use more than 3 hours
a day as a criterion for excessive internet use, 41% of 727 Portuguese
adolescents engaged in more than 3 hours a day but the authors only considered
19% of the adolescents internet dependent [53]. In this study, phone and
laptop were the main devices used and social networks and online games were the
main activities. Internet dependence was associated with mainly Twitter and
Instagram use, with self-perceived sleep problems, insomnia and excessive
daytime sleepiness. In a study on problematic internet use in 2,010 Korean
adolescents, physically active students were less likely to have sleep problems
and less likely to be problematic internet users [54]. The inverse
relationship between physical activity and problematic internet use was
mediated by increased sleep satisfaction. Although internet addiction would
conceivably be strongly related to inactivity, it is surprising that very few
studies have tapped the physical activity variable.
Overweight is another
variable that is seemingly related to the inactivity associated with excessive
internet use. Although activity was not reported in a study from Switzerland on
621 adolescents, overweight adolescents were significantly more likely to use
the Internet more than two hours per day [55]. As the authors pointed out,
internet use could be a reinforcer of already existing overweight. In another
study conducted in seven European countries (N=10,287), problematic internet
use was associated with a higher risk of overweight/obesity [56].
Psychological
problems. Psychological problems associated with internet addiction in the
recent literature include depression and suicidal ideation. In a sample of 385
high school students, internet addiction symptoms were associated with
traumatic experiences for the male students and depression symptoms for the
female students [57]. Excessive internet use was a mediating factor
between allergic illnesses and suicidal ideation after adjusting for school and
family factors in a study on Korean youth (N=73,238 students) [58]. The
19% rate of suicidal ideation in that sample seems extremely high. In another
South Korean sample surveyed by another group of investigators, data from
221,265 middle and high school students suggested that high risk users as
compared to potential-risk users were more likely to report suicidal ideation
or attempts [59].
Family relationship
problems. Surprisingly very few studies have been conducted on family and peer
relationship problems in adolescents with problematic Internet use. The peer
and parent relationship problems reported for high internet use adolescents
back in 2000 apparently did not inspire new studies (Sanders et al,
2000) [1]. The search for novel problems and the reluctance to conduct
replication studies is a problem with this literature. But it is surprising
that relationship measures have not been collected in the very large samples of
adolescents in the studies reviewed here. Using latent profile analysis, a
group of German investigators formed a profile group with pathological internet
use from a sample of 1,723 adolescents [60]. The high internet use group
showed lower levels of family functioning and more difficult family
interactions. Unlike other studies, the results of their latent profile
analysis were validated not only by the adolescents’ self-reports but also by
the adolescents’ caregivers’ ratings. In a study on 814 Spanish high school
students, both family and peer relationships were affected by Internet abuse,
and the internet abusers (approximately 25% of the sample) had poorer face-to
-face interactions skills than virtual social skills [61].
Peer relationships.
Data from a few Facebook studies suggest negative effects of internet addiction
on peer relationships. In one study, a Facebook Intrusion Questionnaire was
developed based on internet addiction [62]. Facebook intrusion was related
to dissatisfaction with peer relationships, to jealous cognitions and to
surveillance behaviors. In another Facebook study, research participants were
asked to imagine viewing their romantic partners’ Facebook [63]. The
researchers varied the hypothetical privacy settings and the number of the
couples’ photos on Facebook. Negative emotions resulted including jealousy, anger,
disgust and hurt, especially for the females who felt these more intensely than
the males. In a survey of 205 Facebook users, a high level of Facebook use was
related to negative relationship outcomes, and these were mediated by
Facebook-related conflict, especially among those who had new
relationships [64].
Academic performance
problems. These have included lower grades and school burnout. Excessive
internet use has been associated with lower school grades in a sample of 905
Dutch high school students via an online survey [65]. Mixed-effects
regression models were used to assess the mediating effects of psychosocial
problems. Compulsive internet use along with being bullied, bullying and
smoking were associated with low grades via the mediating effects of
psychosocial problems. The Compulsive Internet Use Scale (CIUS) was also used
with 417 Chinese adolescents [66]. Male adolescents were more likely to be
compulsive internet users, and the CIUS scores were correlated with daily
internet use time and negatively correlated with academic performance.
Excessive internet use has also been associated with school burnout among
Finnish early and late adolescents (N=3338) [67]. Using two longitudinal
data waves and structural equation modeling, the data analyses revealed
cross-legged paths between excessive internet use and school burnout, with
school burnout predicting later excessive internet use and excessive internet
use predicting later school burnout. Again, in this sample, more boys
experienced excessive internet use and more girls suffered from depression.
Related addictions.
Related addictions studies have included cell phone addiction, internet gaming,
sexting, cyberdating abuse, cyberbullying and substance abuse. They are briefly
reviewed here as they have been significantly highly related to internet
addiction in adolescents.
Cell phone addiction
is significantly related to internet addiction, although it has a distinct user
profile, for example, it occurs more frequently in females [68] and
especially those with low self-esteem [69]. Like internet addiction, its
prevalence has varied (0-38%) depending on the scale used and the location of
the research [69]. And, in some countries smart phones are continuously
connected to the internet (for example, 89 % time in a sample of 609 Turkish
tenth grade students) [70]. As in internet addiction, cell phone addiction
has been associated with sleep disturbances, anxiety, depression and substance
abuse including smoking and alcohol [68,71].
Internet gaming.
Internet addiction and internet gaming have been noted to augment the symptoms
of each other in a sample of 509 adolescents [72]. Like internet
addiction, internet gaming disorder has been shown to increase functional
connectivity density in the dorsal lateral prefrontal cortex [73].
Sexting (the exchange
of sexually explicit content via cell phone, internet or social networks) is
related to both internet and cell phone addiction. In a Los Angeles study on
1,285 middle school students 5% of students reported sending sexts, and 20%
reportedly received sexts [74]. Both groups were more likely to report
sexual activity as well as unprotected sex and condom use. In a review of the
sexting literature, sexting occurred more in older adolescents, and more
individuals reported receiving than sending sexts [75]. Sexting among boys
has been related to their perceptions of peer approval, and those perceptions
of approval, in turn, predicted increased experience with sexual
behavior [76]. Sexting has been more prevalent in males and has related to
more online dating violence in a sample of 1,334 adolescents [77]. And
sexting has been associated with earlier sexual behavior, bullying, substance
abuse, depression and suicide [78]. Sexting, like excessive internet
use, has been associated with relational anxiety [79]. In this study, fear
of negative evaluation from the dating partner predicted sending nude photos or
sexually suggestive messages. Greater social distress when dating was also
associated with sexting behaviors.
Cyberbullying is one
of the most serious problems associated with internet and cell phone
addictions. In a sample of 265 females, 27% of the students had experienced
cyberbullying, 17% had experienced depression and 38% met the criteria for
problem drinking [80]. Those involved in cyberbullying as bullies had
increased odds of both depression and problem alcohol use, while bully victims
had increased odds of depression, with the highest odds for those who had
received unwanted online or text message sexual advances. In an even younger
sample of sixth graders, as many as 15% had experienced cyberbullying at least
once [81]. In a very large sample of 8053 students from 30 middle schools
and 21 high schools, pathological internet use was noted in 10% of the students
and 7% were cyberbullying victims and 7% perpetrators of
cyberbullying [82]. In this cross-sectional study, hours of daily internet
use on a mobile phone was associated with internet abuse and cyberbullying.
Substance abuse
including tobacco, marijuana and alcohol use have been frequently reported
among adolescents with internet addiction. In one study on 11,931 European
adolescents, 90% of the adolescents had multiple risk-taking
behaviors [83]. The strongest associations with pathological internet use
were poor sleeping habits and risk–taking behaviors along with tobacco use,
poor nutrition and physical inactivity. Similarly, tobacco drug use was
reported on a U.S. sample who completed both Young’s Diagnostic Questionnaire
and the Compulsive Internet Use Scale [84]. In this sample, students who
spent more than 25 hours per week on the internet for non-school or
non-work-related activities reported internet–associated health and/or
psychosocial problems including sleep deprivation, failure to concentrate,
academic under-achievement, lack of exercise, lack of face-to-face social
interactions and negative mood states. These students also reported that they
had first experienced the internet at an average age of nine years and had a
problem with internet overuse at an average age of 16.
Swiss adolescents who
had high scores on the Internet Addiction Test and averaged 14 years of age
(N=3,067) were more likely to be female, to be below average on their academic
performance, and to use significantly more drugs including tobacco, alcohol and
marijuana [85]. In the same Swiss sample by the same investigators, a
backward logistic regression suggested that problematic internet users were
more prone to spend their leisure time online, to access the internet via a smart
phone or tablet, to be physically inactive, to have less emotional well-being
and to smoke [86]. In a survey study from Germany on 1,444 adolescents,
approximately 5% of the sample reported both problematic internet use and
problematic alcohol use [87]. Conduct problems and depression symptoms
were also associated with problematic internet use and alcohol use.
In one of the largest
samples from the U.S., adolescents (N=21,170 8th graders and 24,362 10th
graders) were asked questions about internet use outside school or work and
binge drinking [88]. A dose-response relation was noted between internet use
and binge drinking, a relationship that was stronger for the eighth-graders
than the 10th-graders.
These effects
variables, irrespective of whether they are truly effects variables or whether
they are risk factors or comorbidities with internet addiction combine to
suggest the need for early interventions, at least before 8th grade.
Unfortunately, very few intervention studies have been conducted. Screening for
interventions and designing interventions may be difficult partially because
many risk factors have been identified which would result in false positives
as, for example, depression does not necessarily lead to internet addiction.
High-risk profiles need to be identified based on multivariate studies and
profile analysis. These countless large-sample effects studies from many
countries that include several variables might be reanalyzed for risk profiles.
In several studies risks and effects have been reciprocal such that directions
of effects are difficult to determine. However, profile analyses might be more
informative than correlation analyses for intervention research.
5. Intervention
Research on Internet Addiction in Adolescents
Although only one
group assignment intervention therapy study could be found in the recent
literature, studies that report parental restriction of internet use and
parental monitoring of internet use might also be considered intervention
studies. In a study on 2,021 adolescents from Hong Kong, 24% of the adolescents
scored high on internet addiction [36]. In a logistic regression, adolescents
from low income, divorced families experienced more internet addiction. As the
authors noted, adolescents with restricted internet use were almost 2 times
more likely to have internet addiction than those who were not restricted. In
contrast, parental restrictive mediation has had positive effects in other
studies. For example, in a sample of 1,808 junior high school students in
Taiwan, the adolescents who reported high levels of parental restrictive
mediation were less likely to experience internet addiction or cyberbullying.
Internet addiction in this sample was associated with very negative outcomes
including cyberbullying and victimization/perpetration, depression, smoking and
alcohol consumption.
The protective effects
of parental monitoring of internet use were also noted in an online survey of
629 adolescents [89]. In a structural equations model, parental monitoring
effects were direct and 26 times greater than parental internet restriction
effects. Parental monitoring was associated with reduced rates of online
harassment, and lower rates of harassment were indirectly related to limited
internet access in the adolescents’ bedrooms. In another study, supportive
parental monitoring of internet use was related to less pathological internet
use in adolescents [87].
In a group therapy
study that could be found in the recent literature on internet use by
adolescents, 92 adolescents with internet addiction and their parents were
assigned to an experimental group of 6 sessions of group therapy or a waitlist
control group [90]. Assessments were made at pre-intervention,
post-intervention and a three-month follow-up. As might be expected, a
significant decline occurred in both the average score and the proportion of
adolescents with internet addiction in the therapy group which was surprisingly
maintained at the 3-month follow-up assessment. The reports from the
adolescents and their parents suggested that these improvements related to
improved parent-adolescent interactions. In a meta-analysis of interventions
for internet addiction, integrative therapy had a larger effect size compared
to other therapies such as reality therapy and cognitive behavior therapy [91].
In this meta-analysis, interventions that included 9-12 people had larger
effect sizes than those who had fewer or more people and interventions that
lasted 8 or more weeks revealed larger effect sizes as compared to shorter
interventions.
6. Limitations
of the Literature and Future Directions
Survey studies on
prevalence, risk factors and effects data comprise most of the recent
literature on internet addiction in adolescents. Only a few interventions were
noted in this recent literature including restricted internet use and
monitoring by parents as well as group therapy. Methodological limitations of
this research include the lack of a standard internet addiction classification
and the reliance on self-report questionnaires that often do not include time
spent online and online behaviors. Smaller sample observational and laboratory
studies are needed to understand specific online behaviors and the risk factors
associated with internet addiction in adolescents. For example, social anxiety
would seem to be associated with internet addiction, yet it has not been
reported in these large survey samples.
Further, most of the
recent studies are correlational so that direction of effects cannot be
determined. The usual problems of correlation studies apply for these studies
including the lack of control over confounding variables. Regression and
structural equations analysis models could have been used in these large sample
studies to control for potentially confounding variables and to determine the
relative contribution of these variables to the outcome variance on internet
addiction in adolescents.
As internet addiction is associated with so many other demographic, psychological and behavioral problems as well as comorbid addictions, there is a need for more multivariate research and profile/regression/structural equation modeling that can identify the relative variance explained by these variables. Identifying high risk profiles could then be translated into clinical interventions. It would seem that interventions that have been effectively used with other addictions could be tried with adolescents who are experiencing internet addiction including, for example, the parent monitoring protocols that have been effective, exercise programs, meditation and cognitive behavior therapy. In addition, with internet addiction and other addictions like cell phone addiction, sexting, cyberbullying and substance use occurring even in pre-adolescence, school-based education programs are needed for both parents and students along with teacher and peer monitoring of these addictive behaviors.
The internet and cell-phone technology that was
intended for communication and educational purposes has become addictive and
problematic for many aspects of the health and well-being of younger and
younger adolescents. The survey studies reviewed here have highlighted the
prevalence, risks and effects of internet addiction. However, more small-scale
empirical studies are needed to explore the specific internet addiction and
related addiction behaviors, the personality and non-internet activity profiles
of the adolescents and the underlying mechanisms to inform the even more needed
early intervention/prevention studies.
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