Background
Prolonged stress is a risk factor for developing mental illness and stress-related diseases. As there has been an increase in self-reported psychological symptoms and diagnosis of mental illness among Scandinavian adolescents, more knowledge of stress prevalence in this age group is needed.

Aim
This literature review will investigate a possible increase in stress prevalence among Scandinavian adolescents, aged 13-18, between the years 2000 and 2019.

Methods
A systematic literature search was conducted in the PubMed and PsycInfo databases. In addition, a grey literature search was conducted to find relevant surveys and reports. Altogether, nine papers and nine surveys, and reports containing relevant data were identified, assessed for risk of bias, and included in the analysis.

Results
The results show higher stress scores among the older participants in the age group 13-18 years and a gender difference, where girls score higher than boys. The literature neither supports nor rejects the hypothesis that stress levels have increased among adolescents in Scandinavia, from year 2000 to 2019. Only two of the included studies used a validated stress questionnaire and there was a substantial risk of non-response bias. Therefore, the existing literature is considered insufficient to determine if there has been an increase in stress over time. A majority of the papers, surveys, and reports had moderate risk of bias.

Conclusions
Further research using validated stress questionnaires in representative populations is needed to investigate changes in stress prevalence among Scandinavian adolescents. Also, the age and gender difference in stress prevalence among 13-18-year-olds may be of relevance for planning preventive interventions to reduce stress.