BACKGROUND: Adolescence is often seen as an important period for further personality development. In today's world, it is therefore important to keep track of current trends in adolescents. One of them is addictive behaviour in the context of the online environment. Spending too much time online can have a negative impact on the quality of life of adolescents. It is therefore important to pay increased attention to this phenomenon and to respond adequately to the current situation. METHODS: Our study focuses on the prevalence of Internet addiction among Czech and Slovak adolescents. In total, 3,741 respondents participated in the project (N = 2,642 CZ; N = 1,099 SK); their ages ranged from 11 to 19 years (M = 14.38; SD ± 2.27). The research addressed differences among individual types of schools and between sexes in relation to Internet addiction. The research focused on adolescents attending secondary schools (ISCED 2 and 3) between the ages of 11 and 19 in the Czech and Slovak Republics. A questionnaire battery consisting of a sociodemographic questionnaire and the Internet Addiction Test (IAT) questionnaire was used for data collection. RESULTS: In relation to the category of Internet use, girls did not score higher than boys either in the Czech group F(1, 2112) = .089, p = .765, or in the Slovak group F(1, 927) < .001 p = .994. There is a significant effect of school type both in the Czech group F(4, 2100) = 11.483, p < .001, and in the Slovak group F(4, 859) = 2.859, p = .023. CONCLUSIONS: Our research indicates that some adolescents, particularly boys, face issues with excessive Internet use, affecting social interactions. Further studies in the Czech Republic could explore the link between psychosocial factors and adolescent Internet use. This highlights the need to raise awareness among professionals about Internet addiction in Czech and Slovak adolescents.

• Klíčová slova
• Adolescents, IAT, Internet addiction, Prevalence, School,
• MeSH
• chování mladistvých psychologie   MeSH
• dítě MeSH
• internet statistika a číselné údaje   MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• návykové chování epidemiologie   psychologie   MeSH
• netholismus * epidemiologie   psychologie   MeSH
• prevalence MeSH
• průzkumy a dotazníky MeSH
• sexuální faktory MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Slovenská republika epidemiologie   MeSH

BACKGROUND AND AIMS: The aim of the present study was to estimate the complex association between Internet Gaming Disorder (IGD), substance use, and other risky behaviours in Czech adolescents whilst providing prevalence estimates of IGD and psychometric information regarding the Czech Internet Gaming Disorder Scale-Short-Form (IGDS9-SF). METHODS: A representative sample of 3,950 Czech adolescents was recruited through stratified random sampling in the school setting. RESULTS: Disordered gamers showed frequent use of specific substances such as pharmaceuticals, methylenedioxymethamphetamine, and lysergic acid diethylamide. In contrast, non-gamers had higher prevalence of alcohol, cigarettes, sedatives and tranquillisers, and marijuana use. A logistic regression, utilising IGDS9-SF raw scores and average daily gaming time, revealed a U-shaped relationship between gaming and both alcohol and cigarette use. Additionally, conduct problems such as bullying, and risky in-game behaviours were more prevalent among disordered gamers, with the exception of forging parents' signatures. The overall prevalence of IGD was 3.62% (95% CI = [3.1%, 4.3%]), with higher rates in males (5.89%; 95% CI = [4.9%, 7.0%]) than in females (1.45%; 95% CI = [1.0%, 2.1%]). DISCUSSION AND CONCLUSIONS: The Czech IGDS9-SF used in the present study showed adequate psychometric properties. The association between gaming and substance use behaviours may be specific and multifaceted depending on the severity of the gaming-related problems. Furthermore, disordered gamers may become more vulnerable due to a higher incidence of conduct problems, bullying (victimisation), and in-game risky behaviours such as engagement with microtransactions mechanics (e.g., loot box) within video games.

• Klíčová slova
• adolescence classification, conduct problems, internet gaming disorder, risky behaviour, substance use,
• MeSH
• chování mladistvých * MeSH
• lidé MeSH
• mladiství MeSH
• netholismus * epidemiologie   MeSH
• poruchy spojené s užíváním psychoaktivních látek * epidemiologie   MeSH
• prevalence MeSH
• riskování * MeSH
• videohry statistika a číselné údaje   MeSH
• Check Tag
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH

In 2019, Gaming Disorder (GD) was acknowledged as an official diagnosis by the World Health Organization. The Gaming Disorder Test (GDT) is the most widely used tool to measure GD; however, due to its novelty, various measurement properties are still unexplored, and the number of validated language variants is still limited. The present study is the first to assess the psychometric properties of the Czech version of the GDT. Further, it focuses on its temporal prevalence and stability, gaming genre invariance, and criterion validity. A large-scale sample of adult Czech gamers collected at two points within nine months was analysed - T1 N = 5356; T2 N = 6077; longitudinal sample N = 1430. Confirmatory factor analysis (CFA), structural equation modelling (SEM), and multigroup CFA were employed to assess the measurement invariance. The study confirmed the one-factor structure of the GDT and showed that it is invariant across preferred gaming genres and the time of data collection. It showed a negative relationship with life satisfaction and a positive relationship with anxiety, even when controlling for their mutual relationships. The prevalence in the longitudinal sample was equal to or below 1.9% in each wave, but only 0.5% in the longitudinal sample (hence n = 7 participants fulfilled in both waves the criteria for GD). The study suggests that the Czech version of the GDT has good psychometric properties, including temporal stability and invariance across gaming genres, so it is suitable for the survey type and epidemiological investigation of the ICD-11's Gaming Disorder.

• Klíčová slova
• Gaming disorder, Gaming disorder test, Longitudinal investigation, Measurement invariance, Prevalence, Validation,
• MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• longitudinální studie MeSH
• mladiství MeSH
• mladý dospělý MeSH
• netholismus diagnóza   epidemiologie   MeSH
• prevalence MeSH
• psychiatrické posuzovací škály normy   MeSH
• psychometrie * normy   přístrojové vybavení   MeSH
• reprodukovatelnost výsledků MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH

Internet addiction is a serious problem among young adults that requires increased attention, especially at a time of distance learning during the coronavirus disease 2019 (COVID-19) pandemic. The aim of the study was to assess the relationships between internet addiction and selected socio-demographic, study-related, and psychological characteristics of college students. Internet addiction was measured using the Internet Addiction Test both overall and in its individual subscales (Salience, Excessive Use, Neglect Work, Anticipation, Lack of Control, and Neglect Social Life). The selected characteristics represented (1) socio-demographic profile (gender, age, residence, family), (2) academic profile (housing during the semester, form of study), and (3) psychological profile (depressive symptoms-the Patient Health Questionnaire, stress-the Perceived Stress Scale, anxiety symptoms-the Generalized Anxiety Disorder). Data collection took place during the first wave of the COVID-19 pandemic in 2020 at Czech and Slovak colleges, with 1,422 students from the Czech Republic and 1,677 students from Slovakia participating in the research. The analytical processes were carried out through descriptive analysis, non-parametric difference analysis, and multiple negative binomial regression. Mild internet addiction was found in 387 (27.2%) Czech and 452 (27.0%) Slovak students. Moderate internet addiction was identified in 49 (3.4%) students from the Czech Republic and in 100 (6.0%) students from Slovakia. Two (0.1%) Czech and three (0.2%) Slovak students reported severe internet addiction. Increased likelihood of internet addiction overall, as well as in most individual subscales, was found particularly among male students and students who lived away from home during the semester. Depressive symptoms and stress could also be considered significant predictors in both countries. These results are important for the development of effective strategies and prevention programs, as Internet addiction may be a serious problem in the future, given the current times. When assessing internet addiction among college students, it would also be appropriate to evaluate the individual internet addiction subscales and their specifics.

• Klíčová slova
• anxiety symptoms, depressive symptoms, mental health, problematic internet use, relationships, socio-demographic characteristics, stress, study-related characteristics,
• MeSH
• COVID-19 * epidemiologie   MeSH
• demografie MeSH
• lidé MeSH
• mladý dospělý MeSH
• návykové chování * epidemiologie   psychologie   MeSH
• netholismus epidemiologie   MeSH
• pandemie MeSH
• průřezové studie MeSH
• průzkumy a dotazníky MeSH
• studenti psychologie   MeSH
• Check Tag
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Slovenská republika epidemiologie   MeSH

Poor mental health is a growing concern among young people during the coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to assess the associations of Internet addiction with depressive symptoms, anxiety symptoms, and stress in higher education students during the COVID-19 pandemic, as well as to examine these mental health problems in the context of study-related characteristics. The research sample consisted of 3,099 participants from the Czech Republic (CZ: 1,422) and Slovak Republic (SK: 1,677). The Internet Addiction Test (IAT), the Generalized Anxiety Disorder (GAD-7) scale, the Patient Health Questionnaire for depressive symptoms (PHQ-9), and the Perceived Stress Scale (PSS) were used to measure mental health problems. The analyses also included demographic data (gender and age) and study-related characteristics (form of study, degree of study, field of study, distance between college and home, and housing during the semester). Based on the results of frequency and descriptive analyses, the prevalence of mental health problems was high. The most serious levels of Internet addiction (IAT cut-off point ≥ 50), to which attention should be paid, were found in 3.5% of Czech and 6.2% of Slovak students. Using the standard cut-off point of GAD-7 ≥ 10, 14.1% of Czech and 11.6% of Slovak students were identified with anxiety symptoms. Regarding the PHQ-9 with the cut-off point ≥ 10, 23.4% of Czech and 19.1% of Slovak students had depressive symptoms, which should be addressed. Using the PSS cut-off point ≥ 27, 12.9% of Czech students and 9.1% of Slovak students perceived high stress. The quantile regression analysis showed that Internet addiction was positively associated with anxiety symptoms, depressive symptoms, and stress in all of the analyzed cases (p-value < 0.001). In terms of study-related characteristics, the binomial logistic regression analysis revealed that risk factors for mental health problems in Czech and Slovak students were mainly full-time form of study and living away from home during the semester. Internet addiction, anxiety symptoms, depressive symptoms, and stress are issues that require increased attention, and professionals and policy-makers should implement interventions to effectively prevent and help students with psychological problems.

• Klíčová slova
• GAD-7, IAT, PHQ-9, PSS, college, mental health problems, young people,
• MeSH
• COVID-19 * epidemiologie   MeSH
• deprese epidemiologie   MeSH
• lidé MeSH
• mladiství MeSH
• netholismus epidemiologie   MeSH
• pandemie * MeSH
• psychický stres epidemiologie   MeSH
• studenti psychologie   MeSH
• úzkost epidemiologie   MeSH
• úzkostné poruchy epidemiologie   MeSH
• Check Tag
• lidé MeSH
• mladiství MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH