• addiction;
  • adolescents;
  • comorbidity;
  • Internet;
  • psychiatric disorders


  1. Top of page
  2. Abstract
  3. Method
  4. Results
  5. Discussion
  6. Acknowledgments
  7. References


To investigate prevalence and patterns of psychiatric disorders in young subjects with Internet addiction (IA).


Subjects were taken from a sample of patients, aged 10–18 years old, referred to Istanbul Medical Faculty, Child and Adolescent Psychiatry Department due to a variety of behavioral and emotional problems alongside problematic Internet use. Inclusion criteria included IQ ≥70 and score ≥80 on Young's Internet Addiction Scale (YIAS). Psychiatric comorbidity was assessed using the Turkish version of the Schedule for Affective Disorders and Schizophrenia for School Age Children–Present and Lifetime Version.


Subjects were 45 boys (75%) and 15 girls (25%) with an age range of 10–18 years old (mean age, 13.38 ± 1.79 years). A total of 60% (n = 36) had been using Internet for ≥5 years. Mean hours/week spent on the Internet was 53.7 (range, 30–105 h) and the average YIAS score was 85. All subjects (100%) had at least one and 88.3% (n = 53) had at least two comorbid psychiatric disorders. The frequency of diagnostic groups were as follows: behavioral disorder, n = 52 (86.7%); anxiety disorder, n = 43 (71.7%); mood disorder, n = 23 (38.3%); elimination disorder, n = 16 (26.7%); tic disorder, n = 10 (16.7%); and substance use disorder, n = 4 (6.7%). The most common psychiatric disorders were attention-deficit hyperactivity disorder (n = 53; 83.3%), social phobia (n = 21; 35.0%) and major depressive disorder (n = 18; 30.0%).


High rates of psychiatric comorbidity, particularly behavioral, anxiety and mood disorders were found in young subjects with IA. Because the presence of psychiatric disorders may affect the management /prognosis of IA, assessment should include that for other psychiatric disorders.

THE INTERNET IS an integral part of modern life and it provides an easy and immediate way for people to explore information and communicate with other people around the world. It has become widespread in the lives of children and adolescents in recent years. Loss of control over Internet use, however, might lead to negative impacts on individual psychological wellbeing, peer and family interactions, academic performance and daily life functions.[1, 2] This phenomenon has been described as Internet addiction (IA) or problematic Internet use[3, 4] and conceptualized as a category of behavioral addiction.[5] The other terms to describe negative effects of Internet use include ‘compulsive Internet use’, ‘pathological Internet use’, ‘Internet dependency’ and even ‘Internetomania’.[6]

Studies suggest that IA is frequently related to psychiatric disorders, and the presence of these conditions in individuals with IA is the rule rather than the exception.[7, 8] Whether IA should be considered as a primary addictive disorder or secondary disorder due to other psychiatric conditions, however, is still unclear. The presence of psychiatric comorbidities may have further impact on psychosocial functioning and treatment outcome for IA. Mood disorders, anxiety disorders, substance abuse and attention-deficit hyperactivity disorder (ADHD) are found to be among the most common comorbidities.[7, 8]

Given the significance of psychiatric disorders on IA, structured diagnostic interview is necessary for the detection of psychiatric comorbidities because it provides greater diagnostic accuracy and contributes to more comprehensive evaluation. Almost all of the studies have assessed comorbidity using self-reports or parent and teacher evaluation rather than by diagnostic interview. But the number of studies based on structured psychiatric interview in this area is very limited.[7-11] There are only five interview studies on the psychiatric comorbidity of IA in the literature and four of them were carried out in adults.[7-10] The only study conducted on children and adolescents was the study by Ha et al.[11] In that study Ha et al. used diagnostic interview to evaluate psychiatric comorbidity in 12 children and 12 adolescents, under 18 years old, classified as Internet addicts based on self-report questionnaire. Of this sample, seven children were diagnosed with ADHD or subthreshold ADHD, and three adolescents with major depressive disorder (MDD).

To our knowledge, there no other study has investigated the prevalence and patterns of psychiatric disorders among young subjects with IA or problematic Internet use. The aim of this study was to investigate sociodemographic characteristics, and prevalence and patterns of psychiatric disorders in referred young subjects with IA using structured interview.


  1. Top of page
  2. Abstract
  3. Method
  4. Results
  5. Discussion
  6. Acknowledgments
  7. References


Subjects for this study were recruited from a clinical sample of young patients referred to the Child and Adolescent Psychiatry Department at Istanbul Faculty of Medicine, Istanbul University. Inclusion criteria were (i) age between 10 and 18 years old; (ii) problematic Internet use and related academic, social difficulties and/or physical and/or mental health problems; (iii) Young's Internet Addiction Scale (YIAS) score ≥80; (iv) IQ ≥70 on Wechsler Intelligence Scale for Children–Revised (WISC-R); and (v) subject assent and parental informed consent to participate in the study. Exclusion criteria were (i) diagnosis of autism spectrum disorders or mental retardation; and (ii) diagnosis of any neurologic or metabolic disorder.


Interview form

This form was developed by the authors to assess sociodemographic information, Internet use habits, academic, social and daily life difficulties and physical symptoms possibly related to Internet use.

Young's Internet Addiction Scale

The YIAS is a self-report questionnaire composed of 20 questions with a 5-point Likert scale ranging from 1 (rarely) to 5 (always).[12] It is one of the most widely used scales for the evaluation of IA. The scale was translated and adapted to Turkish by Bayraktar.[13] The 20 items of the YIAS are calibrated, with scores ranging from 20 to 100, with higher scores reflecting a greater tendency toward addiction. Three types of Internet use were identified: IA; limited symptoms; and no symptoms; the corresponding scores were: ≥80; 50–79; and <50, respectively. Cut-off points of the YIAS may differ from one country to another based on the Internet use style of the culture. The cut-off point of the Turkish YIAS was reported to be ≥80. The internal consistency of the Turkish YIAS is 0.91.

Schedule for Affective Disorders and Schizophrenia for School Age Children–Present and Lifetime Version–Turkish Version

The Schedule for Affective Disorders and Schizophrenia for School Age Children–Present and Lifetime Version (K-SADS-PL) is a semi-structured interview schedule designed to assess major psychiatric disorders in children and adolescents on the basis of DSM-IV criteria.[14] The Turkish version of the K-SADS-PL (K-SADS-PL-T) was used in this study.[15]


Subjects who were referred to the clinic underwent routine clinical assessment. Subjects who had problematic Internet use as one of the major referral concerns were further assessed for study participation. During initial interview subjects were interviewed for sociodemographics, Internet use habits, academic, social difficulties and physical symptoms possibly related to Internet use. They were required to have a YIAS score ≥80 and IQ ≥70 on WISC-R to be included in the study. Thereafter subjects and parents were interviewed in combined and separate sessions for psychiatric assessment using K-SADS-PL-T, after informed consent from parents and assent from subjects had been obtained. A faculty ethics committee approved the study.

Statistical analysis

All statistical analysis was done using SPSS 15.0 (SPSS, Chicago, IL, USA). Pearson χ2 test was used to compare the association between psychiatric comorbidity and gender. Statistical significance was set at two-tailed P < 0.05.


  1. Top of page
  2. Abstract
  3. Method
  4. Results
  5. Discussion
  6. Acknowledgments
  7. References

Subjects and Internet use

The study sample consisted of 60 subjects (45 male, 15 female) with a mean age of 13.38 ± 1.79 years. All participants were fourth- to twelfth-grade students. Of the participants, 60 (100%) had a computer and 57 (95%) had an Internet connection at home. Thirty-six of them had been using the Internet for ≥5 years and the rest had been using it for 1–5 years. Mean hours/week spent on the Internet was 53.7 (range, 30–105 h). The average YIAS score was 85. All subjects used the Internet for more than one purpose. Male subjects tended to spend more time playing online games (88% of male subjects) while female subjects were found to be more interested in social networking sites (100% of female subjects). A total of 58% of the sample preferred to chat online and 25% of them hid their real identity. Twenty-nine (48.3%) of the subjects also reported physical symptoms due to problematic Internet use (e.g. head, neck and back pain, numbness in fingers, lachrymation of eyes). In addition, family conflicts related to problematic Internet use were reported in 95% of the sample. A total of 85% of the male subjects had a history of missing school at least once, while the rate for missing school at least once was 40% for the female subjects. A total of 70% of the subjects had at least one poor grade in the end-term school report. Moreover, 50% of the subjects admitted stealing money from their parents/home for online games, while 80% of them preferred to engage in Internet activities rather than to spend time with their family or friends.

Psychiatric comorbidity

All subjects met criteria for at least one lifetime DSM-IV Axis I diagnosis. The prevalence and patterns of psychiatric disorders are given in Table 1. A total of 88% of the subjects had two or more, and 65% had three or more psychiatric diagnoses. The frequencies of the diagnostic groups were as follows: behavioral disorder, 86.7%; anxiety disorder, 71.7%; mood disorder, 38.3%; elimination disorder, 26.7%; tic disorder, 16.7%; and substance use disorder, 6.7%. The most common psychiatric disorders were ADHD (83.3%), social phobia (SoP; 35.0%) and MDD (30.0%). ADHD-combined subtype was significantly more frequent in male subjects while SoP was more frequent in female subject.

Table 1. Psychiatric disorders in IA subjects aged 10–18 years (n = 60)
  1. *Statistical significance (P < 0.05) for ADHD-combined type (Pearson χ2 = 9.25, P = 0.002) and social phobia (Pearson χ2 = 5.49, P = 0.019) between male and female subjects. ADHD, attention-deficit hyperactivity disorder; IA, Internet addiction; NOS, not otherwise specified.

Behavioral disorder5286.7
Combined* (M/F)2440 (51.1/6.7)
Oppositional defiant disorder1423.3
Conduct disorder915
Anxiety disorder4371.7
Separation anxiety disorder1423.3
Social phobia* (M/F)2135 (26.7/60.0)
Specific phobia915
Obsessive–compulsive disorder1525
Panic disorder11.7
Anxiety NOS46.7
Post-traumatic stress disorder23.3
Mood disorder2338.3
Major depressive disorder1830
Depression NOS23.3
Bipolar disorder11.7
Elimination disorder1626.7
Tic disorder1016.7
Chronic tic711.7
Transient tic35
Substance abuse46.7


  1. Top of page
  2. Abstract
  3. Method
  4. Results
  5. Discussion
  6. Acknowledgments
  7. References

Internet addiction may have a significant impact on academic and social life, and those having IA may also suffer a number of behavioral and/or emotional problems. To our knowledge, the present study is the second clinical study to assess the prevalence and patterns of psychiatric comorbidity in young subjects with IA using a standardized psychiatric interview (the K-SADS-PL-T). The results show that adolescents with IA may have higher rates of psychopathology, particularly behavioral, anxiety and mood disorders. The present findings are generally consistent with other studies reporting psychiatric symptoms in problematic Internet users.

The rates and comorbidity of psychiatric disorders in the present study, however, are higher than those of previous studies conducted in community or clinical samples. Merikangas et al. investigated lifetime prevalence and comorbidity of DSM-IV psychiatric disorders in a large community sample of adolescents (n = 10.123) aged 13–18 years of age.[16] They reported that 49% of all subjects received at least one diagnosis. Rates of comorbidity were 24% for two, and 18% for three or more disorders among subjects who received at least one diagnosis. On comparison of the present study and the Merikangas et al. study, there was a significant difference in the rates of subjects who received at least one (100% vs 49%; P < 0.0001), two (88% vs 24%; P < 0.0001), and three or more diagnoses (65% vs 18%; P < 0.0001).

The high rates of comorbidity may raise the question of whether referral bias may have resulted in overestimation of psychiatric disorders in this sample. Almost all of the present participants were referred to the clinic due to a variety of behavioral and emotional problems in addition to excessive Internet use. Therefore these conditions may have contributed to the high rate of psychiatric disorders.

Prior studies have found that comorbidity in IA is the rule rather than the exception.[17-19] Therefore ascertainment of comorbid psychiatric disorders should be a part of through clinical assessment in young subjects with IA. To date, there are a limited number of studies on psychiatric comorbidity that have utilized structured psychiatric interview, in individuals with IA. Table 2 lists a summary and comparison of those studies.

Table 2. Summary and comparison of IA studies
 Black et al. (1999)[7]Shapira et al. (2000)[8]Ha et al. (2006)[11]Ko et al. (2008)[9]Bernardi and Pallanti[10]Present study
  1. CVMNI, Chinese Version of the Mini-International Neuropsychiatric Interview; DIS, Diagnostic Interview Schedule; GAD, generalized anxiety disorder; IA, Internet addiction; KSADS, Kiddie Schedule for Affective Disorders and Schizophrenia for School Aged Children; MIDI, Minnesota Impulsive Disorders Interview; NA, not assessed; NI, no information; PD, panic disorder; PTSD, post-traumatic stress disorder; SAD, separation anxiety disorder; SCID, Structured Clinical Interviews for DSM-IV; SP, specific phobia.

Age (years)>18>18<1818–27>18<18
n (M/F)21 (16/5)20 (11/9)24 (20/4)87 (65/22)15 (6/9)60 (45/15)
Diagnostic rate (%)50100505085100
Behavioral disorder (%)NANA   87
Anxiety disorder (%)19604  72
Mood disorder (%)3370   38
Depressive disorder15101318738
Bipolar disorderNI600NA72
Psychotic disorder (%)14104NA00
Substance abuse (%)38100NA07
Eating disorder (%)NI150NA70
Impulse control disorder (%)38350NA0NA
Elimination disorder (%)NANA0NANA27
Tic disorder (%)NANA0NANA17

Behavioral disorders

The most common disorder diagnosed in the present study was ADHD (83.3%). ADHD affects 5–10% of children and 4% of adults in the general population.[20] Studies on IA suggest that problematic Internet use is usually associated with ADHD and related symptoms.[9, 21] Children and adolescents with IA are also more likely to have ADHD than their peers without IA.[21, 22]

Given that the studies reported higher rates for ADHD in comparison with the general population, we also found higher rates in the present outpatient sample.

The ADHD-inattention subtype was found to be more frequent than other subtypes in the present study and the rates were higher in girls than in boys (60% vs 37%). There is insufficient information on ADHD subtype in individuals with IA in the literature. Yen et al. found that attention deficit was the subtype most frequently associated with IA among the ADHD symptoms. and the association was more prominent among female subjects,[22] consistent with the present findings.

There have been some possible mechanisms to explain the association between IA and ADHD. Studies suggest that reward deficiency and impaired inhibition are found to be strongly associated factors between these two conditions.[23-25]

The rates for oppositional defiant disorder (ODD) and conduct disorder (CD) in the present study were 23% and 15%, respectively. Other than the present study, there has been no study on the comorbidity between other disruptive behavior disorders and IA, given that ODD and CD are the psychiatric conditions of childhood and most of the other studies were conducted with older adolescents and young adults. Lack of studies based on diagnostic structured interview may also explain the reason. But ODD and CD are among the most common disorders comorbid with ADHD in children, so the present results are not surprising. Furthermore, studies also suggest that online violent games were found to have a negative impact on disruptive behaviors such as anti-social aggression and delinquency or vice versa.[26, 27]

Anxiety disorders

Anxiety disorders were the second most common diagnostic group in the present study. The most common anxiety disorder was SoP (35%) followed by OCD (25%). Although the rates are high when compared with the general population, the present findings are consistent with the results of other studies reporting psychiatric comorbidity in individuals with IA. Black et al. found that 19% of adults with IA had anxiety disorders,[7] while Shapira et al. reported that 40% of their sample was classified as having SoP.[8] Bernardi and Pallanti also identified SoP with a prevalence of 15% in adult cases of IA.[10] High shyness and loneliness scores have been noted to be associated with problematic Internet use among college students in another study.[28] Moreover a 2-year follow-up study found that social anxiety symptoms could predict the emergence of IA.[29]

Internet provides non-face-to-face communication with anonymity, so individuals with low social competence prefer Internet use rather than face-to-face interaction to compensate for their social inabilities. In this context, this type of communication gives them greater flexibility in self-presentation. Morahan-Martin and Schumacher define the Internet as the ‘Prozac of social communication’.[30]

We found that 58% of the present sample preferred to chat online and 25% of them hid their real identity. Girls spent more time in social networking sites, and SoP was found to be more common in girls in the present study. These findings also support the association between SoP and IA in the literature.

Obsessive compulsive disorder (OCD) was the second most common anxiety disorder in the this study (25%). The rate was also higher than in the general population but not surprising for individuals with IA. Some of the studies emphasize the relationship between OCD and IA. De Berardis et al. found that alexithymic students with IA had higher obsessive–compulsive symptoms than their peers.[31] Some researchers have considered Internet usage as part of the OCD spectrum, and a compulsive Internet use scale has also been developed in this context.[32] But Ha et al. diagnosed OCD only in one case in their sample of 24 children and adolescents.[11] Further research based on structured psychiatric interview is needed to address this comorbidity.

Mood disorders

Mood disorders were the third most common diagnostic group in the present study. Depressive disorders comprised the whole of this group. MDD (30%) was also found to be the third most common axis I disorder. Like behavioral and anxiety disorders, previous reports suggest high rates for depression in problematic Internet users. Black et al. found the lifetime prevalence of mood disorders and MDD to be 33% and 15%, respectively.[7] Bernardi and Pallanti reported that 7% of adults with IA had comorbid dysthymic disorder.[10] Furthermore, Ha et al. reported an association between IA and depression among adolescents in a Korean sample,[11] and Ko et al. conducted a prospective questionnaire study to show that adolescents with depression are more likely to become Internet-addicted in the 2-year follow-up period.[29] The high rates for mood disorders found in the present study also contribute to the possible relationship between depression and IA suggested by the aforementioned findings.

The Internet provides children and adolescents with social support, achievement, the pleasure of control and a virtual world in which they can escape from emotional difficulty in the real world. Depressive individuals may use the Internet to overcome depression, and become more prone to excessive Internet use. In contrast, Internet-addicted individuals report high levels of depression, loneliness and social isolation, turning the condition into a vicious circle. Additionally, a Korean study found a possible genetic link between depression and IA.[33]

Only one subject had a history of drug-induced manic episode in the present study. The relationship between bipolar disorder (BP) and IA is not well studied. In a case series that included 20 patients, Shapira et al. found a high (70%) lifetime prevalence for BP type 1 or 2.[8] The other interview studies, however, reported lower rates or no connection between the two conditions, similar to the present study. The low rate of BP in the present study could be related to the relatively younger age of the subjects and diagnostic overshadowing.

Other psychiatric disorders

Almost 7% of the present subjects sample met the criteria for substance abuse. A total of 23% and 20% of them had a history of smoking and alcohol use without abuse or dependence, respectively. Substance abuse and related problems seem to be associated with IA. Some researchers have suggested that a tendency to substance abuse could also sensitize individuals to other addiction types. Because the Internet has the potential to be addictive, children and adolescents with vulnerability to substance use disorders may be vulnerable to IA.

Bai et al. first noted the high prevalence of substance use disorders among IA subjects in a virtual clinic.[34] Lam et al. noted that adolescents with alcohol drinking behavior were more likely to have IA.[35] Black et al. found the lifetime prevalence of substance use disorder to be 38% in adults with IA,[7] and Shapira et al. reported that 10% of the IA subjects had alcohol abuse in their interview study.[8] Furthermore, Ko et al. noted that cue-induced gaming urges activated similar brain areas corresponding to substance craving in a functional magnetic resonance study.[36] All these findings support the possible relationship between substance abuse and IA. More studies are needed, however, to test the idea that IA has similar neurobiological and genetic features to substance use disorders.

The other axis I psychiatric illnesses in the present study were tic disorder (16.7%) and elimination disorder (26.7%). To our knowledge, there is no study on the coexistence of these conditions and IA. Because the most common disorder in the present outpatient sample was ADHD, and tic disorders are more likely to accompany behavioral disorders, high rates are not surprising. Internet-related psychological problems may also affect the clinical course of tics. Also, parents reported that their children sat at the computer for hours, forgetting to go to the toilet, and enuresis or encopresis worsened with excessive use of the Internet. Three of 16 children with elimination disorder were also found to have new-onset enuresis or encopresis associated with problematic computer use without a previous history of incontinence. Further studies focusing on children with IA are necessary to extend the knowledge about the other psychiatric disorders usually seen in this type of patient.


This study had several limitations such as the relatively small sample size of clinically referred subjects, possible referral bias contributing to high rates of psychopathology, and lack of a control group, which may limit generalization of the findings. As stated, the present subjects were referred for a variety of behavioral and/or emotional problems alongside problematic Internet use. We included only those subjects whose problematic Internet use was considered to reach IA as measured on the YIAS. Therefore the present findings may not reflect all young subjects with problematic Internet use.


Despite these limitations this diagnostic interview study identified high rates of externalizing and internalizing psychiatric disorders in adolescents with IA. Therefore comorbid psychiatric disorders should be taken into consideration when assessing and managing young subjects with IA. Public and professional awareness should be increased regarding IA and its impact on physical and mental health in youth. More research is needed to further explore the relationship between IA and psychiatric disorders, and preventing and managing IA among young subjects.


  1. Top of page
  2. Abstract
  3. Method
  4. Results
  5. Discussion
  6. Acknowledgments
  7. References

The authors state that they have no conflicts of interest in general or in connection with the submitted article and no financial relationships with any pharmaceutical company.


  1. Top of page
  2. Abstract
  3. Method
  4. Results
  5. Discussion
  6. Acknowledgments
  7. References
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