The aim of this systematic literature review is to map the longitudinal research in the field of Internet Use (IU) and Problematic Internet Use (PIU) in adolescents and emergent adults. Further, this study endeavours to examine the terminology and instruments utilized in longitudinal IU and PIU research and investigate whether statistically significant results have arisen from the areas of research focus. In a total of 29 studies, trends in the research of adolescent/emergent adult IU and PIU were discovered. These trends were conceptualized into individual, contextual and activity-related factors. Findings suggested that individual factors are the most researched and have demonstrated significant relationships with adolescent/young adult PIU. However, more research on contextual and activity-related factors is needed in order to achieve a clearer understanding of young people's IU and PIU behaviours, and to incorporate into a comprehensive model that will guide future research in this growing field.

Background and aimsThe risk effect of anxiety on addictive behaviors, including Internet addiction (IA), has repeatedly been highlighted in the international literature. However, there is a lack of longitudinal studies examining this association in relation to proximal context effects, particularly in adolescence. Such findings would shed light on potential age- and proximal context-related variations in the anxiety–IA association that could better inform IA prevention and intervention initiatives.MethodsIn this study, 648 adolescents, embedded in 34 classrooms, were assessed at the age of 16 and again at the age of 18 to examine the effect of anxiety on IA behaviors in relation to the average level of classroom extraversion. IA was assessed with the Internet Addiction Test (Young, 1998), anxiety with the relevant subscale of the Symptom Checklist 90 – Revised (Derogatis & Savitz, 1999) and classroom extraversion with the synonymous subscale of the Five Factor Questionnaire (Asendorpf & van Aken, 2003). A three-level hierarchical linear model was calculated.ResultsThe present findings demonstrated that: (a) higher levels of anxiety were significantly associated with higher IA behaviors, (b) the strength of this association did not vary over time (between 16 and 18 years old), and (c) however, it tended to weaken within classrooms higher in extraversion.DiscussionThis study indicated that the contribution of individual IA risk factors might differently unfold within different contexts.

However, excessive alcohol intake had reoccurred at 3-month follow-up, accompanied by increases in negative affect and impairment due to eating, indicating that longer-term therapy may be required for this group of people.

Objective: Socio-economic-status (SES) has rarely been reported or investigated in eating disorders (EDs) research. This Research Forum considers, from various perspectives, how SES may impact on evaluating evidence-based treatments for EDs. Method:We first reviewed previous literature that informs how SES impacts prevalence of EDs, help-seeking, and treatment outcome. We then present findings from a case series effectiveness study of an early intervention program in low SES areas for EDs and discuss implications about the impact of SES on the effectiveness of evidence-based interventions. Finally, we examine barriers to conducting rigorous evaluations in this population and discuss directions for future treatment outcome research.Results: Evidence suggests a higher level of disordered eating but less help seeking in lower SES groups. In our case series, 96 participants started treatment and completed a mean of 13.85 sessions, 84 (87.5%) completed a mean of 6.40 sessional measures on ED cognitions and behaviors, but only 31% completed more extensive pretreatment and post-treatment measures. The completer effect size decrease for the global Eating Disorder Examination-Questionnaire score was 2.05 (95% CI: 1.43, 2.68) commensurate with other effectiveness studies in mixed SES groups. The high rates of missing data related to more extensive assessment present a barrier to evaluating evidence-based treatments in this population.Discussion: Evidence from the present study revealed individuals from low SES can achieve similar treatment outcomes to other populations when receiving evidencebased ED treatment. Future studies should investigate a range of approaches to maximizing data collection, including use of shorter sessional measures.