Abstract
Mental health problems are increasing among adolescents, where stress, screen time, social media and sleep deprivation are contributing factors. The aim of this study was to explore adolescents' understanding and self-reporting of health for further development of the screening tool HEILUNG. Mixed-method study design based on qualitative (focus groups) and quantitative data (cross-sectional study) was used. The participants in both studies were adolescents in upper secondary schools across Iceland. The framework method was used in the data analysis for the focus groups and descriptive statistics for the cross-sectional study (CSS). The focus groups included 31 participants, and the CSS 648. The focus groups showed that mental health was important and dependent on physical and social health. Almost 56%, 45% and 27% of the participants (CSS) were stressed, anxious and depressed often/daily, respectively. Mental well-being was affected by sleep deprivation and social media. More than half of the participants (CSS) did not get enough sleep, and approximately 38% had seven hours or more of screen time daily. Mental health was of great concern to adolescents in both studies affected by many influential factors. Making health decisions regularly was difficult for them. They needed opportunities to discuss health issues and health promotion, which could be provided by school nurses.