ABSTRACT Importance Problematic use of the internet (PUI) behaviors, including problematic gaming, social media use, smartphone use, and general internet use, have been increasingly studied worldwide. So far it is unclear what the global prevalence of PUI is. Objective To critically appraise existing systematic reviews and meta-analyses on the prevalence of PUI behaviors and generate aggregated global prevalence estimates across different manifestations and definitions. Data Sources MEDLINE (Ovid), Embase (Ovid), Scopus, Web of Science, CINAHL, and the Cochrane Review Library were searched for relevant articles from database inception to the most recent available search prior to manuscript preparation. Searches targeted systematic reviews and meta-analyses reporting prevalence for PUI-related behaviors. Study Selection Systematic reviews and meta-analyses of observational studies reporting prevalence estimates for problematic gaming, problematic internet use, problematic smartphone use, problematic social media use, or sexting were included. Scoping reviews were retained for descriptive synthesis only. Data Extraction and Synthesis An umbrella review methodology was used. Data extraction and methodological appraisal were conducted using AMSTAR-2 to assess the quality of included systematic reviews up to February 2026. Primary studies included in each review were extracted and pooled using random-effects meta-analysis. Analyses were conducted to estimate pooled prevalence with 95% confidence intervals (CIs) and heterogeneity across non-overlapping primary studies. Small-study effects were examined. Main Outcomes and Measures Global pooled prevalence estimates for PUI behaviors, including problematic gaming, problematic internet use, problematic smartphone use, problematic social media use, and sexting. Results Eleven reviews (10 systematic reviews and 1 scoping review) met inclusion criteria, representing data from 3 145 428 individuals, of whom 3 030 023 were included in pooled prevalence analyses. Across regions, pooled prevalence estimates were 6% (95% CI, 5%–7%) for problematic gaming, 16% (95% CI, 15%–17%) for problematic internet use, 32% (95% CI, 28%–35%) for problematic smartphone use, and 23% (95% CI, 19%–28%) for problematic social media use. Substantial heterogeneity (I 2 > 99%) was observed across primary studies, reflecting variation in study methodologies, sampled populations, and definitions of PUI behaviors. Conclusions and Relevance PUI behaviors appear to affect a substantial proportion of the global population. However, methodological concerns were common, with 9 of 10 systematic reviews rated as having low or critically low confidence according to AMSTAR-2. Evidence remains concentrated in East Asia and Europe, and many reviews combine heterogeneous populations and sampling strategies. Additional high-quality epidemiological research, including underrepresented regions is needed to refine prevalence estimates, clarify risk factors, and support the development of standardized criteria for PUI behaviors. Key Points Question What is the global prevalence of problematic use of the internet (PUI) behaviors across major subtypes, based on an umbrella review of existing reviews and a meta-analysis of nonoverlapping primary studies? Findings In this umbrella review of 11 reviews and random-effects meta-analysis of 753 nonoverlapping primary studies including 3 030 023 individuals, pooled prevalence estimates were 6% for problematic gaming, 16% for problematic internet use, 32% for problematic smartphone use, and 23% for problematic social media use. Findings indicated substantial between-study heterogeneity, and most included systematic reviews were rated low or critically low in methodological quality. Meaning These findings suggest that PUI behaviors affect a substantial proportion of the global population, but more methodologically rigorous and geographically representative epidemiological research is needed to generate more precise and comparable prevalence estimates across clinical and population samples.

BACKGROUND:There is increasing global concern about the harms associated with problematic usage of the internet (PUI) affecting young people. Various risk factors have been proposed, but there is a scarcity of reliable evidence on the extent of the problem, who is most at risk of developing PUI and why, and how best to tackle it. OBJECTIVES:BootStRaP (ISRCTN59576080) is a five-year multinational research programme designed to boost young people's health and resilience by determining, through prospective longitudinal assessment, the risk factors associated with PUI and its health economic impact and designing and testing preventative self-management interventions tailored to individual risk factors. METHODS:This paper describes the first phase of the project (i.e., Cohort 1). A sample of over 2500 schoolchildren aged 12-16 years was recruited across nine European countries. They were prospectively monitored over a 6-month period using a dedicated smartphone application (BootstrApp), through which their internet use habits, health and wellbeing were measured. Young people were involved in the co-design of aspects of the protocol including the recruitment plan and elements of the app design. The components of the assessment battery were chosen to investigate specific individual, clinical, cognitive and environmental risk determinants as defined a priori in an evidence-based logic-model. Participants were assessed using a combination of standardised demographic and clinical questionnaires, ambulatory assessment techniques, cognitive testing and passive digital monitoring. Multimodal data is analysed according to machine learning and structured equation modelling. EXPECTED OUTCOMES:Our findings will contribute toward A) developing algorithms for predicting individuals at risk for PUI, B) identifying actionable variables for application to subjects as interventions for testing in the second phase of the project, C) validating risk hypotheses stated in the logic model of PUI including the interplay between predisposing risk factors (e.g., impulsivity, compulsivity), affective and cognitive processes (e.g., reward-related attentional biases), and executive functions (e.g., inhibitory control), D) calculating the health economic cost and impact of PUI in young people across Europe.

Half to three-fourths of mental disorders appear during adolescence or young adulthood, and the treatment gap is mainly due to lack of knowledge, lack of perceived need, and the stigmatization of mental illness. The aims of this study were to implement and evaluate a Mental Health First Aid (MHFA) training program among undergraduates. Participants were second-year students from two universities in the French-speaking region of Switzerland (N = 107), who were randomly assigned to an intervention group (n = 53) or control group (n = 54). The intervention group received a 12-h MHFA course. Online questionnaires were completed before the intervention (T0), and both 3 months (T1) and 12 months (T2) after the intervention in order to evaluate the participants’ mental health knowledge, recognition of schizophrenia, and attitudes and behaviors towards mental illness. We used Generalized Estimating Equations (GEE) to examine the effects of intervention over time. After the MHFA course, the intervention group showed significantly increased basic knowledge and confidence helping others with mental illness and reduced stigmatization at both T1 and T2 compared to their baseline scores and compared to control groups. This suggests that the MHFA training program is effective and has significant short-term and long-term impacts, in terms of enhancing basic knowledge about mental health and improving attitudes towards mental illness among undergraduate students.

Most of the studies that examine the effect of the COVID-19 pandemic on mental health have been restricted to pandemic mental health data alone. The aim of the current study was to estimate the pandemic’s effect on young Swiss adults’ mental health by comparing pandemic to pre-pandemic mental health. Longitudinal data of 1175 young Swiss adults who participated in the S-YESMH study in 2018 and were followed-up in 2020 and 2021 were analyzed. The study outcomes were self-reported symptoms of depression, generalized anxiety disorder (GAD), attention-deficit/hyperactivity disorder (ADHD), thoughts about death or self-harm, and risky single-occasion drinking (RSOD). Generalized estimation equations, logistic regression and statistical mediation analysis were used to analyze the data. Evidence was found of increased depression, GAD, and ADHD among young women and increased depression among young men, resulting from the COVID-19 pandemic. Uncertainty about the future predicted young women’s depression and anxiety in 2021. COVID-19 stress in 2021 fully mediated the effect of COVID-19 stress in 2020 on depression and GAD in 2021. Young Swiss women’s and men’s mental health appears to have been adversely affected by the COVID-19 pandemic, especially during the second pandemic year. Uncertainty about the future and stress becoming chronic in 2021 likely explain some of the adverse effects.

This longitudinal, prospective study investigated associations between perceived COVID-19-related stress, coping strategies, and mental health status among adolescents during the first lockdown of the COVID-19 pandemic and one year after the lockdown in Switzerland within a large, national sample. A self-report on-line survey was completed by 553 adolescents (age-range 12–18 years in 2021) in the summers of 2020 and 2021, assessing symptoms of various mental health problems, perceived COVID-19-related stressors, and coping strategies. Overall, participants reported less COVID-19 related stress one year after the lockdown, though mental health status remained stable. ‘Challenges at home or with others’ were significantly associated with mental health problems in both genders, whereas ‘trouble getting medical care or mental health services ‘was associated with mental health problems in girls. Perceived stress and pre-existing psychiatric problem were significantly linked to all mental health outcomes at both time points. Parents’ poor relationships with partners during the lockdown was associated with increased anxiety symptoms in their children. Using cognitive restructuring to cope with stress was associated with less, while negative coping was associated with more anxiety, depression, and attention deficit hyperactivity disorder (ADHD) symptoms one year post lockdown. Girls appear to have been more affected by the pandemic than boys, with youths with pre-existing psychiatric problems especially vulnerable to its detrimental effects. Healthcare and school professionals should support to identify high-risk adolescents with negative and avoidant coping strategies and train youths to use positive coping strategies.

Background: Previous research has demonstrated a preventive effect of the alcohol policy environment on alcohol consumption. However, little is known about the heterogeneity of this effect. Our aim was to examine the extent of heterogeneity in the relationship between the strictness of alcohol policy environments and heavy drinking and to identify potential moderators of the relationship. Methods: Cross-sectional data from 5986 young Swiss men participating in the cohort study on substance use risk factors (C-SURF) were analysed. The primary outcome was self-reported risky single-occasion drinking in the past 12 months (RSOD, defined as 6 standard drinks or more on a single occasion at least monthly). A previously-used index of alcohol policy environment strictness across Swiss cantons was analysed in conjunction with 21 potential moderator variables. Random forest machine learning captured high-dimensional interaction effects, while individual conditional expectations captured the heterogeneity induced by the interaction effects and identified moderators. Results: Predicted subject-specific absolute risk reductions in RSOD risk ranged from 16.8% to -4.2%, indicating considerable heterogeneity. Sensation seeking and antisocial personality disorder (ASPD) were major moderators that reduced the preventive relationship between stricter alcohol policy environments and RSOD risk. They also were associated with the paradoxical observation that some individuals displayed increased RSOD risk in stricter alcohol policy environments. Conclusion: Whereas stricter alcohol policy environments were associated with reduced average RSOD risk, additionally addressing the risk conveyed by sensation seeking and ASPD would deliver an interlocking pre-vention mix against young Swiss men's RSOD.

OBJECTIVE:To treat patients with psoriasis vulgaris using Traditional Chinese Medicine (TCM), one must stratify patients into subtypes (known as TCM syndromes or Zheng) and apply appropriate TCM treatments to different subtypes. However, no unified symptom-based classification scheme of subtypes (Zheng) exists for psoriasis vulgaris. The present paper aims to classify patients with psoriasis vulgaris into different subtypes via the analysis of clinical TCM symptom and sign data.METHODS:A cross-sectional survey was carried out in Beijing from 2005-2008, collecting clinical TCM symptom and sign data from 2764 patients with psoriasis vulgaris. Roughly 108 symptoms and signs were initially analyzed using latent tree analysis, with a selection of the resulting latent variables then used as features to cluster patients into subtypes.RESULTS:The initial latent tree analysis yielded a model with 43 latent variables. The second phase of the analysis divided patients into three subtype groups with clear TCM Zheng connotations: 'blood deficiency and wind dryness'; 'blood heat'; and 'blood stasis'.CONCLUSIONS:Via two-phase analysis of clinic symptom and sign data, three different Zheng subtypes were identified for psoriasis vulgaris. Statistical characteristics of the three subtypes are presented. This constitutes an evidence-based solution to the syndromedifferentiation problem that exists with psoriasis vulgaris.

The prevalence of different routes of administration (ROAs) of illicit drugs other than cannabis was examined in young Swiss men, in addition to the association between socio-demographics and adverse outcomes and particular ROAs. Our sample consisted of 754 men (mean age = 25.4 ± 1.2 years) who participated in the Cohort Study on Substance Use Risk Factors and reported using any of 18 illicit drugs over the last 12 months. Prevalence estimates were calculated for oral use, nasal use, smoking, injecting, and other ROAs. Associations between ROAs and socio-demographics and adverse outcomes (i.e., alcohol use disorder (AUD), suicidal ideations, and health and social consequences) were calculated for using single versus multiple ROAs. The most prevalent ROA was oral use (71.8%), followed by nasal use (59.2%), smoking (22.1%), injecting (1.1%), and other ROAs (1.7%). Subjects' education, financial autonomy, and civil status were associated with specific ROAs. Smoking was associated with suicidal ideations and adverse health consequences and multiple ROAs with AUD, suicidal ideations, and health and social consequences. The most problematic pattern of drug use among young adults appears to be using multiple ROAs, followed by smoking. Strategies to prevent and reduce the use of such practices are needed to avoid adverse outcomes at this young age.

IntroductionThe alcohol policy environment was shown to exert a preventive effect on alcohol consumption. However, little is known about the heterogeneity of this effect.ObjectivesTo capture the extent of heterogeneity in the relationship between the strictness of alcohol policy environments and heavy drinking and to identify potential effect modifiers.MethodsMethod: Cross-sectional data from 5986 young Swiss men participating in the cohort study on substance use risk factors (C-SURF) in Switzerland was analysed. Self-reported risky single-occasion drinking (RSOD, drinking 6 standard drinks or more on a single occasion at least monthly) in the past 12 months was the outcome of interest. A previously-used index of alcohol policy environment strictness across Swiss cantons was analysed in conjunction with 21 potential effect modifiers. Random forest machine learning and individual conditional expectations captured high-dimensional interaction effects and the heterogeneity induced by the interaction effects and identified potential effect modifiers.ResultsSubject-specific absolute risk reductions ranged from 16.8% to -4.2%, with the latter implying a risk increase. Four prototypical subgroups were evident: “preventive” (alcohol policy environment decreased RSOD risk), “causative” (alcohol policy environment increased RSOD risk), “immune” (no effect due to low RSOD baseline risk), and “doomed” (no effect due to high RSOD baseline risk). Antisocial personality disorder and sensation seeking were major effect modifiers that reduced the preventive effect of stricter alcohol policy environments.ConclusionsConclusion: Whereas stricter alcohol policy environments were associated with a reduced RSOD risk, adding selective prevention measures that target high-risk subpopulations is necessary.DisclosureNo significant relationships.

The present study aimed to assess various stressful situations and the psychological impact of the first COVID-19 pandemic lockdown among youths in Switzerland. We included samples of 1627 young adults aged 19–24 from the Swiss Youth Epidemiological Study on Mental Health and 1146 children and adolescents aged 12–17 years and their parents. We assessed symptoms of various mental health problems, internet use, and perceived stress during the first COVID-19 lockdown. In the analyses, data were weighted to be representative of the Swiss population. During the first lockdown in Switzerland, the most common sources of perceived stress were the disruption of social life and important activities, uncertainty about how long the state of affairs would last, and the pandemic itself. In addition, around one-fifth of the young adults met the criteria for at least one of the mental health problems (attention deficit hyperactivity disorder, depression, generalized anxiety disorder), while one-third of children/adolescents screened positive for at least one of the mental health problems (attention deficit hyperactivity disorder, oppositional defiant disorder, depression, anxiety). Moreover, 30.1% of children and 21.3% of young adults met the criteria for problematic internet use. The study showed considerable stress perceived by young adults and symptoms of mental health problems, especially among females, during the first COVID-19 lockdown in Switzerland.

IMPORTANCE There are concerns that the use of water pipes to consume cannabis is associated with increased risks of engaging in more addictive behaviors. OBJECTIVE To examine whether consuming cannabis with a water pipe was associated with later consumption of other illicit drugs compared with not using a water pipe. DESIGN, SETTING, AND PARTICIPANTS The Cohort Study on Substance Use Risk Factors (C-SURF) was a population-based study, recruiting 5987 Swiss men aged 18 to 25 years from 3 of 6 Swiss Armed Forces recruitment centers (response rate: 79.2%). The baseline assessment (t0) was done from 2010 to 2012, first follow-up (t1) from 2012 to 2014, and second follow-up (t2) from 2016 to 2018. Our sample included men who participated in both t0 and t2 assessments and used cannabis but no other illicit drugs at t0. Data analysis was performed from July 2020 to January 2021. EXPOSURES Cannabis use frequency and route of administration from self-administered questionnaires completed at t0 and t2. MAIN OUTCOMES AND MEASURES Outcome measures were initiation of illicit drug use and cannabis use disorder, identified by the Cannabis Use Disorder Identification Test. To examine whether water pipe use at t0 was associated with illicit drug use at t2, multivariable logistic regression analysis was performed. RESULTS Among 1108 Swiss male cannabis users who did not use other illicit drugs at t0, the mean (SD) age was 20 (1.2) years, 617 (55.7%) were from Switzerland's French-speaking region, and 343 (30%) used water pipes to consume cannabis. Water pipe users at t0 were more likely to use other illicit drugs at t2 compared with water pipe nonusers (adjusted odds ratio [aOR], 1.54; 95% CI, 1.10-2.16). The odds of using middle-stage drugs (including stimulants, hallucinogens, and inhaled drugs) at t2 were increased for water pipe users (aOR, 1.61; 95% CI, 1.13-2.29). Water pipe use at t0 was not associated with cannabis use disorder at t2 after adjusting for cannabis use frequency. CONCLUSIONS AND RELEVANCE This cohort study's results suggest that, among Swiss young men, water pipe use is associated with other illicit drug use later in life, particularly middle-stage illicit drugs. Preventive programs must focus on the potential of later harm to cannabis users who use water pipes but have not yet started taking other illicit drugs.

This paper evaluates the interaction between level of parental monitoring in adolescence and individual dispositions present in early adulthood in the prediction of alcohol use disorder (AUD) in the mid-20s. Data were drawn from the Cohort Study on Substance Use Risk Factors (C-SURF), encompassing 4844 young Swiss men who were surveyed three times within a 5-year period. The outcome variable was alcohol use disorder (AUD) as defined in the DSM-5. Independent variables were sensation seeking (Brief Sensation Seeking Scale) and the coping strategies active coping and denial (Brief COPE). Low parental monitoring, high sensation seeking, and high denial were found risk factors of AUD (odds ratio (OR) = 1.21 (1.05–1.40); OR = 1.56 (1.37–1.78); OR = 1.15 (1.01–1.31)). A significant interaction effect was identified between active coping and parental monitoring; high active coping in early adulthood was found protective of AUD, only among individuals who had low parental monitoring in adolescence (OR = 0.70 (0.52–0.96)). In addition to interventions to upskill parents for improving monitoring, other interventions directed to young adults who had disadvantaged family contexts could be implemented, with the aim of enhancing the use of adaptive coping strategies such as active coping. Prevention targeting avoidant coping strategies and sensation seeking should be privileged too.

Aims. Mental disorders in children are a significant and growing cause of morbidity worldwide. Although interventions to help overcome barriers along the pathway to accessing health care for children with mental disorders exist, there is no overview of randomised controlled trials (RCTs) on these interventions as yet. This study aimed to systematically identify RCTs of interventions to improve access to mental health care for children and synthesise them using a conceptual framework of access to health care.Methods. This systematic review was performed following a predefined protocol registered with PROSPERO (ID: CRD42018081714). We searched the databases MEDLINE, EMBASE, PsycINFO and CENTRAL for RCTs up to 15 May 2019 using terms related to the concepts 'young people,' 'mental disorders' and 'help-seeking interventions' and scanned reference lists from relevant studies. Two reviewers independently screened all identified articles in a two-stage process, extracted results on outcomes of interest (knowledge, attitudes, intentions, help-seeking, accessing care, mental health outcomes and satisfaction), assessed the risk of bias and conducted meta-analyses where deemed appropriate.Results. After screening 5641 identified articles, 34 RCTs were eligible for inclusion. Eighty per cent of universal school-based interventions measuring knowledge (n = 5) and 67% measuring attitudes (n = 6) reported significantly better results compared with controls on those outcomes, whereas 20% measuring access to care (n = 5) and none measuring mental health outcomes (n = 7) did. In contrast, 71% of interventions targeting at-risk individuals (n = 21) reported better access to care compared with controls, while just 33% (n = 6) did for mental health outcomes. For satisfaction with care, this proportion was 80% (n = 5). Meta-analyses of interventions measuring initial appointment attendance yielded combined odds ratios of 3.11 (2.07-4.67) for appointment reminder interventions and 3.51 (2.02-6.11) for treatment engagement interventions. The outcomes for universal school-based interventions were heterogeneous and could not be summarised quantitatively through meta-analysis.Conclusions. To have a population-level effect on improving children's access to mental health care, two-stage interventions that identify those in need and then engage them in the health-care system may be necessary. We need more evidence on interventions to target contextual factors such as affordability and infrastructural barriers.

Introduction: Social cohesion, depression, and problematic substance use are intertwined and poorly understood. This study aimed to examine cross-sectional and longitudinal associations between social cohesion, depression and problematic substance use among young men, age 21-25. Methods: We used 2nd wave (t(1), 2012-2014, N = 6020) and 3rd wave (t(2), 2016-2018) data from the on-going Swiss Cohort Study on Substance Use Risk Factors (C-SURF), assessing social cohesion, depression, and severity of alcohol, nicotine and cannabis use during both waves. Structural Equation Models (SEMs) were employed to examine pathways in both waves under the framework of longitudinal analysis. Results: Social cohesion was directly associated with depression and problem nicotine and cannabis use and indirectly associated with problem alcohol, nicotine and cannabis use through depression at both t(1) and t(2). Social cohesion exerted direct effects on nicotine use and cannabis use severity, but not on alcohol use severity. Social cohesion had indirect effects on problem use of all three substances, mediated via depression. The predictive direction was from depression to substance use, rather than vice versa. Conclusions: Higher social cohesion at an early age appears to protect young males from depression and problematic substance use later in life. However, once problematic substance use is established, the direct effect of social cohesion diminishes and is mediated through personal depression. Therefore, promoting a more cohesive neighborhood in childhood or adolescenthood could play an important role preventing depression and more severe substance use behaviors.

Background Recent studies have uncovered a peculiar finding: that the strength and dimensionality of depression symptoms’ inter-relationships vary systematically across study samples with different average levels of depression severity. Our aim was to examine whether this phenomenon is driven by the proportion of non-affected subjects in the sample. Methods Cross-sectional data from the “Cohort Study on Substance Use Risk Factors” was analyzed. Self-reported depression symptoms were assessed via the Major Depressive Inventory. Symptom data were analyzed via polychoric correlations, principal component analysis, confirmatory factor analysis, Mokken scale analysis, and network analysis. Analyses were carried out across 22 subsamples containing increasingly higher proportions of non-depressed participants. Results were examined as a function of the proportion of non-depressed participants. Results A strong influence of the proportion of non-depressed participants was uncovered: the higher the proportion, the stronger the symptom correlations, higher their tendency towards unidimensionality, better their scalability, and higher the network edge strengths. Comparing the depressed sample with the general population sample, the average symptom correlation increased from 0.29 to 0.51; variance explained by the first eigenvalue increased from 0.36 to 0.56; fit measures from confirmatory one-factor analysis increased from 0.81 to 0.97; the H coefficient of scalability increased from 0.26 to 0.48; and the median network edge increased from 0.00 to 0.07. Conclusions Results of psychometric analyses vary substantially as a function of the proportion of non-depressed participants in the sample being studied. This provides a possible explanation for the lack of reproducibility of previous psychometric studies.

Background: Attention deficit/hyperactivity disorder (ADHD), conduct disorder (CD), and sensation seeking (SS) have been consistently related to a higher risk of substance use (SU) and substance use disorder (SUD). Objectives: To investigate the relationship between ADHD and prevalence rates in males at age 20 and age 25, the initiation of SU and SUD after age 20, and the escalation of SU from age 20 to age 25, and to explore the role of CD and SS in the relation of ADHD with SU and SUD initiation and escalation. Method: Data were obtained as part of the Cohort Study on Substance Use Risk Factors (C-SURF), which focused on young Swiss men aged 20 years at baseline and 25 years at follow-up. Results: Participants who screened positive for ADHD at baseline exhibited a higher rate of SU and SUD than participants who screened negative. The presence of ADHD symptoms at age 20 predicted initiation of all SU between age 20 and age 25, except for alcohol and smoking. After controlling for self-reported CD and SS, ADHD still predicted this late initiation of use of hallucinogens, meth-/amphetamines, and ecstasy/MDMA; non-medical use of ADHD medication and sedatives, and alcohol use disorder (AUD). No escalation of weekly drinking and smoking or annual cannabis use was observed from age 20 to age 25. Conclusion: Screened-positive ADHD is an independent predictor of late SU and AUD, along with self-reported CD and SS. From a public health perspective, identifying ADHD is not only important in childhood and adolescence but also in early adulthood to guide specific interventions to lower risks of drug use initiation and the development of AUD in early adulthood.