Impulsivity in Internet Addiction:

A Comparison with Pathological Gambling

Hae Woo Lee, M.D.,

1,2

Jung-Seok Choi, M.D., Ph.D.,

1,2

Young-Chul Shin, M.D., Ph.D.,

3

Jun-Young Lee, M.D., Ph.D.,

1,2

Hee Yeon Jung, M.D., Ph.D.,

1,2

and Jun Soo Kwon, M.D., Ph.D.

2

Abstract

Internet addiction has been considered to be associated with poor impulse control. The aim of this study is to
compare the trait impulsivity of those suffering from Internet addiction with that of individuals suffering from
pathological gambling. Twenty-seven patients diagnosed with Internet addiction (age: 24.78 – 4.37 years), 27
patients diagnosed with pathological gambling (age: 25.67 – 3.97 years), and 27 healthy controls (age: 25.33 – 2.79
years) were enrolled in this study. All patients were men seeking treatment. Trait impulsivity and the severity of
the Internet addiction and pathological gambling were measured by the Barratt Impulsiveness Scale-11, the
Young’s Internet Addiction Test, and the South Oaks Gambling Screen, respectively. The Beck Depression
Inventory and the Beck Anxiety Inventory were also administered to all subjects. Our results show that those
suffering from Internet addiction showed increased levels of trait impulsivity which were comparable to those of
patients diagnosed with pathological gambling. Additionally, the severity of Internet addiction was positively
correlated with the level of trait impulsivity in patients with Internet addiction. These results state that Internet
addiction can be conceptualized as an impulse control disorder and that trait impulsivity is a marker for
vulnerability to Internet addiction.

Introduction

I

nternet addiction

, defined as an inability to control In-

ternet use, can lead to serious impairment in psychological

and social functioning.

1–4

The individuals with Internet ad-

diction show behavioral problems in Internet use or excessive
Internet usage, and they experience various psychiatric
symptoms such as depressive mood or anxiety.

5,6

Internet

addiction has been categorized as a behavioral addiction,
because it includes several features that are characteristic of
addictions, such as preoccupation, mood changes, tolerance,
withdrawal, and functional impairment.

7

Additionally,

Young

1

and Beard and Wolf

8

have suggested that Internet

addiction is a disorder involving, or at least related to, poor
impulse control. Pathological gambling is also considered a
behavioral addiction and is classified as an impulse control
disorder in the Diagnostic and Statistical Manual of Mental
Disorders, Fourth Edition (DSM-IV).

9

Impulsivity has a range of definitions that include lack

of planning or forethought, reduced perseverance, and
seeking novel experiences.

10

Impulsivity is a trait that has

often been related to addictive behavior.

11

Barnes et al.,

12

Vitaro et al.,

13

Moeller et al.,

14

and De Wit

15

showed evi-

dence that impulsivity is related to addictions to substance
or behaviors (e.g., pathological gambling). Vitaro et al.

13

investigated whether the impulsivity of 12–14-year-olds
could predict problem gambling in late adolescence and
reported evidence in support of the DSM-IV classification
of pathological gambling as an impulse control disorder.
Goudriaan et al.

16

and Grant et al.

17

studied increased

impulsivity in pathological gambling using neurocogni-
tive tasks assessing impulsivity. Patients diagnosed with
pathological gambling had longer reaction times on stop-
signal trials in the stop-signal task, which is indicative
of greater difficulties with regard to inhibiting the stop
responses.

16,17

With regard to impulsivity in Internet addiction, Cao

et al.

18

examined the relationship between impulsivity and

Internet addiction among Chinese adolescents. The authors
showed that the Internet addiction group was more impul-
sive than the control group, as measured by both the Barratt
Impulsiveness Scale 11 (BIS-11) and the Go-Stop impulsivity

1

Department of Psychiatry, SMG-SNU Boramae Medical Center, Seoul, Republic of Korea.

2

Department of Psychiatry, Seoul National University College of Medicine, Seoul, Republic of Korea.

3

Department of Psychiatry, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.

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YBERPSYCHOLOGY

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ETWORKING

Volume 15, Number 7, 2012
ª Mary Ann Liebert, Inc.
DOI: 10.1089/cyber.2012.0063

373

paradigm, supporting the classification of Internet addiction
as an impulse control disorder.

18

Until now, there is no study about the impulsivity in In-

ternet addiction by directly comparing it with that in patho-
logical gambling. This study was performed to determine the
degree to which the subjects diagnosed with Internet addic-
tion, subjects diagnosed with pathological gambling, and
healthy controls demonstrated trait impulsivity as measured
by the BIS-11 and to examine the relationship between the
severity of Internet addiction and the degree of impulsivity.
Treatment-seeking male patients diagnosed with Internet
addiction or pathological gambling were enrolled in this
study.

We hypothesized that the subjects diagnosed with Internet

addiction would show an increased impulsivity that was
comparable to that shown by individuals diagnosed with
pathological gambling.

Materials and Methods

Participants

Twenty-seven patients diagnosed with Internet addiction

(age: 24.78 – 4.37 years), 27 patients diagnosed with patho-
logical gambling (age: 25.67 – 3.97 years), and 27 healthy
controls (age: 25.33 – 2.79 years) were enrolled in this study.
All patients were treatment seeking, that is, they visited our
clinics due to their suffering from Internet use or gambling-
related problems; only male patients were enrolled, because
the prevalence rate of excessive Internet use differs between
men and women, and men are more likely to be problematic
users of the Internet.

19–21

We included homogeneous male

subjects to control variables, affecting the impulsivity, such as
gender and biological factors.

19

Patients were recruited from

the outpatient clinics of the SMG-SNU Boramae Medical
Center and the Kangbuk Samsung Hospital in Seoul, South
Korea.

We assessed the participants using Young’s Internet Ad-

diction Test (IAT),

1

South Oaks Gambling Screen (SOGS),

22

Beck’s Depression Inventory (BDI),

23

and Beck’s Anxiety

Inventory (BAI).

24

Young’s IAT has been proposed by K.S.

Young after the DSM-IV criteria for pathological gambling,
and is commonly used in the world by investigators, the
standardized scale in South Korea. In addition, we can
assess the severity of Internet addiction using the total
score of Young’s IAT. SOGS is also the standardized scale in
South Korea. The subjects with pathological gambling are
classified by the scores of SOGS from level 1 to 3, not as a
dichotomy. Therefore, we can evaluate the relationships
between the impulsivity and severity of symptoms. The
reasons behind the choice of BDI and BAI is to evaluate the
anxiety and depressive symptoms in subjects with Internet
addiction and pathological gambling to control the effect on
impulsivity.

Previous studies have defined excessive Internet users as

those with scores of at least 50 on the IAT.

1,25

However, we

included only subjects with scores of at least 70 on the IAT
who also spent more than 4 hours per day and 30 hours per
week using the Internet to collect the severe Internet addic-
tion group, not the high-risk group with excessive Internet
use. The mean score on the IAT obtained by patients in the
Internet addiction group was 75.67 – 4.60. The mean number
of hours of Internet use per day and per week in this group

were 6.75 – 2.86 and 47.61 – 15.83, respectively. In addition,
the Structured Clinical Interview for DSM-IV (SCID)

26

was

used to identify the past and current psychiatric illnesses. Of
the 27 patients diagnosed with Internet addiction, four ful-
filled the DSM-IV criteria for depressive disorder. The main
purpose of Internet use in all patients with Internet addiction
was online gaming, and no patients used the Internet for
online gambling. The diagnosis of pathological gambling was
based on the SCID.

26

The diagnosis of pathological gambling

was also defined for patients with an SOGS

22,27

score q5. Out

of the 27 patients diagnosed with pathological gambling, 15
were included in our previous report.

28

Healthy controls

were recruited from the local community and had no history
of any psychiatric disorder. Patients with pathological gam-
bling and healthy controls used the Internet for less than 2
hours per day. All patients were drug naı¨ve. The BDI

23

and

the BAI

24

were administered to all subjects to measure de-

pressed and anxious symptoms, respectively. The institu-
tional review boards of the SMG-SNU Boramae Medical
Center and the Kangbuk Samsung Medical Center approved
the study protocol, and all subjects provided written in-
formed consent before participation.

Measures

IAT.

We used the Korean version of Young’s IAT

29

to

assess the severity of Internet addiction. Items in this test are
rated on a five-point scale on which one indicates ‘‘very
rarely,’’ and five indicates ‘‘very frequently.’’ Total scores
were calculated according to Young’s method,

1

and the

possible scores for all 20 items ranged from 20 to 100.

SOGS.

The SOGS consists of a 20-item questionnaire and

is used to screen pathological gambling. Scores of five or
more are considered indicative of pathological gambling.

22,27

We used the Korean version of the SOGS.

27

BIS-11.

We used the BIS-11

30

to measure impulsivity.

The BIS-11 includes three subscales: cognitive impulsiveness,
motor impulsiveness, and nonplanning impulsiveness. We
used the Korean version of the BIS-11.

31

Statistical analysis

All statistical analyses were conducted with SPSS 17.0.

Demographic and clinical data were compared using analy-
ses-of-variance (ANOVAs) tests with Tukey’s post hoc anal-
ysis. The correlation between IAT scores and clinical variables
in subjects with Internet addiction was assessed using Pear-
son’s correlation analysis. Statistical significance was set at
the level of 0.05, which was two tailed.

Results

Demographic and clinical characteristics

Table 1 presents the demographic and clinical character-

istics of the subjects. No significant differences in age or ed-
ucation were observed among the three groups. The three
groups differed significantly in terms of BDI, F(2, 78) = 22.27,
p < 0.01, and BAI, F(2, 78) = 11.36, p < 0.01, scores. Both the
Internet addiction and pathological gambling groups ob-
tained higher scores in the BDI and BAI than did the healthy
controls ( post hoc, p < 0.01). The Internet addiction group was

374

LEE ET AL.

characterized by longer illnesses than was the pathological
gambling group ( p < 0.01).

Comparison of impulsivity among the Internet
addiction, pathological gambling, and healthy
control groups

We found significant differences among the groups with

regard to total scores on the BIS-11, F(2, 78) = 16.68, p < 0.01,
and scores on all three subscales: cognitive impulsiveness,
F(2, 78) = 6.68, p < 0.01, motor impulsiveness, F(2, 78) = 17.12,
p < 0.01, and nonplanning impulsiveness, F(2, 78) = 14.01,
p < 0.01. The post hoc analyses revealed that both the Internet
addiction and pathological gambling groups obtained higher
total scores and higher scores on the three subscales than did
the healthy controls ( p < 0.01). To control the effects of de-
pressive mood and anxiety, we reanalyzed the ANOVA
treating the BDI and BAI as covariates. Significant differences
were observed among three groups with regard to scores for
motor impulsiveness, F(2, 78) = 4.75, p = 0.01. The post hoc an-
alyses revealed that both the Internet addiction and patho-
logical gambling groups obtained higher scores for motor
impulsiveness than did the healthy control group ( p = 0.01 and
p = 0.02, respectively). Furthermore, we conducted a regression
analysis to evaluate how much more likely it is to develop
impulsivity in subjects with Internet addiction and pathologi-
cal gambling than in healthy controls. Each of the Internet
addiction and pathological gambling groups showed signifi-
cantly higher impulsivity compared with the healthy con-
trol group (b = 16.89, confidence interval (C.I): 12.49*21.30,
p < 0.01; b = 15.68, C.I: 12.49*21.30, p < 0.01, respectively).

Relationship between severity of Internet addiction
and impulsivity in the Internet addiction group

We conducted Pearson’s correlation analysis to examine

the relationship between the severity of Internet addiction
and the impulsivity in patients with Internet addiction. We
found that scores on the IAT were positively correlated with
total scores and scores on the three subscales. All correlations
demonstrated a statistical significance ( p < 0.05). Figure 1
shows the relationship between the severity of Internet ad-

diction and total scores on the BIS-11 in patients with Internet
addiction.

Discussion

The present study compared the trait impulsivity, as

measured by the BIS-11, of individuals diagnosed with In-
ternet addiction with that of individuals diagnosed with
pathological gambling from the perspective of considering
Internet addiction to be an impulse control disorder. We
found that the Internet addiction group showed increased
levels of trait impulsivity that were comparable to those

Table

1. Demographic and Clinical Characteristics in Study Subjects

Internet addiction (N = 27) Pathological gambling (N = 27) Healthy controls (N = 27)

Variables

Mean

SD

Mean

SD

Mean

SD

F, t

p

Age (years)

24.78

4.37

25.67

3.97

25.33

2.79

0.38

0.68

Education (years)

14.26

1.93

13.96

1.95

14.67

1.41

1.06

0.35

Duration of illness (years)

11.37

3.68

2.44

1.17

- 12.02 < 0.01

IAT

75.67

4.60

SOGS

17.67

2.77

BDI

15.59

6.52

15.89

10.90

3.48

4.58

22.27 < 0.01

BAI

14.37

8.12

12.59

12.15

3.81

3.78

11.36 < 0.01

BIS-11

Cognitive

19.67

3.14

19.07

4.82

16.30

2.49

6.68 < 0.01

Motor

23.93

4.35

23.67

5.57

17.19

4.36

17.12 < 0.01

Nonplanning

29.59

4.17

29.11

7.85

22.70

2.55

14.01 < 0.01

Total

73.07

8.70

71.85

17.33

56.19

7.40

16.68 < 0.01

SD, standard deviation; IAT, Internet addiction test; SOGS, South Oaks Gambling Screen; BDI, Beck Depression Inventory; BAI, Beck

Anxiety Inventory; BIS-11, Barratt Impulsiveness Scale 11.

FIG. 1.

Correlation between the severity of Internet addic-

tion and the level of impulsivity (total scores on Barratt Im-
pulsiveness Scale-11) in the Internet addiction group (r = 0.64,
p < 0.01). Solid line is the best fit line (r = 0.64, p < 0.01), and
dashed line means a 95 percent confidence interval.

IMPULSIVITY IN INTERNET ADDICTION

375

observed in patients with pathological gambling. In addition,
the severity of Internet addiction was positively correlated
with the level of trait impulsivity in patients diagnosed with
Internet addiction. To our knowledge, this is the first study
that measures trait impulsivity in treatment-seeking patients
with Internet addiction and compares these results with those
obtained from patients with pathological gambling and
healthy controls.

Impulsivity has been addressed as an endophenotype of

individuals at risk for developing addictions, including sub-
stance use disorders and pathological gambling.

10

In partic-

ular, trait impulsivity, which refers to an enduring
personality characteristic, has been reported to be a marker of
susceptibility to pathological gambling.

32

Trait impulsivity

has also been associated with Internet addiction.

18

Cao et al.

18

reported that impulsivity was positively correlated with In-
ternet addiction, supporting the hypothesis that impulsivity
is a risk factor for developing Internet addiction. Park et al.

33

reported that those who overused Internet games showed
greater impulsivity than did normal users, and noted a pos-
itive correlation between the severity of the overuse and im-
pulsivity. Those who overused Internet games had abnormal
glucose metabolism in the brain regions associated with im-
pulse control, suggesting that overuse of Internet games
shares psychological and neural mechanisms with other
types of impulse control disorders and addictions.

33

Based on

previous reports, Internet addiction has been considered an
impulse control disorder. Our current findings also indicated
that patients diagnosed with Internet addiction were char-
acterized by higher levels of trait impulsivity than were
healthy controls and by levels of trait impulsivity which were
comparable to those of patients diagnosed with pathological
gambling. This study may be interpreted as a confirmation of
the construal of Internet addiction as an impulse control
disorder.

The Internet addiction and pathological gambling groups

in this study showed increased depressed and anxious
symptoms. Four patients with Internet addiction also had a
diagnosis of depressive disorder. Indeed, depression has been
reported to be associated with Internet addiction.

34–38

De-

pressed individuals may rely on the Internet as a way of
coping with their depressive state. When we controlled for
the effects of depressed and anxious symptoms on Internet
addiction and impulsivity, the Internet addiction group
demonstrated increased impulsivity, especially motor im-
pulsiveness on the BIS-11. The significant correlation between
the severity of Internet addiction and impulsivity also re-
mained. These findings suggest that the higher trait impul-
sivity in the Internet addiction group may be independent of
mood state.

This study has several limitations. First, the sample size

was small, and only male subjects were included; thus, the
generalization of the results may be limited. Second, this
study is a case-control study design that has limitations in
showing the correlations between impulsivity and clinical
psychiatric symptoms. However, we included drug-naive
patients, and it is important to recruit a homogeneous sample
to control for confounding factors such as medication and
gender effects. Furthermore, we included treatment-seeking
patients, and diagnoses were made by psychiatrists to accu-
rately identify individuals with pathological Internet use or
gambling. Future studies should use larger samples as well as

longitudinal study design to investigate the neurobiological
markers associated with impulsivity among those diagnosed
with Internet addiction.

Conclusion

The present study found that treatment-seeking patients

diagnosed with Internet addiction showed increased trait
impulsivity as measured by the BIS-11 and that their levels of
trait impulsivity were comparable to those of patients diag-
nosed with pathological gambling. We also found a signifi-
cant positive correlation between the severity of Internet
addiction and the level of impulsivity. These results provide
evidence that Internet addiction can be conceptualized as an
impulse control disorder and that trait impulsivity is a mar-
ker for vulnerability to develop Internet addiction.

Author Disclosure Statement

The authors have no conflict of interest.

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Address correspondence to:

Dr. Jung-Seok Choi

Department of Psychiatry

SMG-SNU Boramae Medical Center

20 Boramae-ro 5-gil

Dongjak-gu

Seoul 156-707

Republic of Korea

E-mail: [e-mail]

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