The aim with this thesis was to study adolescents with mental health problems, factors that are associated with mental health problems, visits to the public health nurse (PHN), and how PHNs and other professionals experience the collaboration in school and school health services related to mental health problems.

Methods: Qualitative and quantitative methods were used. Study I included cross-sectional data from Ungdata, with 8052 adolescents. Descriptive statistics and hierarchical regression were used to analyse the data. Study II included individual interviews with 12 boys and qualitative content analysis was used. In study III, four focus group interviews were conducted and analysed with qualitative content analysis. In study IV, 18 PHNs were individually interviewed and a phenomenographic approach was used to analyse the interviews.

Results: Gender differences were seen in the symptoms of depression, family conflicts and economics, lifestyle habits, school satisfaction and use of school health services with girls reporting in a higher proportion than boys. Boys described barriers such as finding the PHN inaccessible, difficulty talking about mental health problems and uncertainty about confidentiality when visiting the PHN. Interprofessional collaboration (IPC) is important for identifying adolescents with mental health problems. Accessibility, having different obligations, lack of criteria and goals and being dependent on others were described as affecting IPC.

Conclusion: There are differences in boys and girls with girls reporting more mental health problems and visiting the school health service more often than boys. Boys described several barriers to visiting the PHN, but, when these barriers were crossed, the boys experienced the visit as positive. Several factors affected IPC in schools and the school health services. There were variations in the collaboration experienced, but when it worked it was experienced as positive.

Mental health problems among adolescents are increasing and are a major public health issue worldwide. The aim of this thesis was to study adolescents with mental health problems, factors that are associated with mental health problems, the visit to the public health nurse (PHN), and how PHNs and other professionals experience interprofessional collaboration (IPC) in school and school health services related to mental health problems. Gender differences in mental health problems, as well as in help-seeking behavior, were identified. Boys visit the PHN to a smaller extent than girls and they experienced barriers such as finding the PHN inaccessible, difficulty talking about their problems with the PHN and uncertainty about confidentiality. When the PHN was trustworthy, confident and supportive, the visit was described as positive.

The PHN in the school health service is in a position to identify mental health problems among adolescents In this setting IPC is essential. Factors such as lack of criteria and goals, different obligations, accessibility and being dependent on others were affecting collaboration. When the professionals and the PHN were included in the IPC, it was experienced as positive.