Subjective health complaints in Norwegian adolescents and associations with stress, sex, and age – Cross-sectional trends over a 10-year period

<i>Aims:</i> This study investigated cross-sectional trends in subjective health complaints (SHCs) over a 10-year period and explored associations between sex, age, normative stress domains, and SHCs. <i>Methods:</i> Data were drawn from three cross-sectional surveys in 2011 (<i>n</i> = 1,289), 2016 (<i>n</i> = 1,233), and 2022 (<i>n</i> =310), including adolescents aged 13-20 from lower- and upper-secondary public schools in rural municipalities in Mid-Norway. SHCs were assessed using a 12-item scale measuring physical and mental symptoms, while stress was measured with the 30-item Adolescent Stress Questionnaire. Descriptive and multiple linear regression analyses were conducted. <i>Results:</i> Average SHC scores were moderately high, showing a slight increase over the study period, and were consistently higher in girls than boys. Age showed a curvilinear association with SHCs, with increasing SHC levels from ages 13 to 16 and declining levels from ages 17 to 20. All stressors associated significantly positively with SHCs controlled for sex and age. Stressors related to the school context were significantly positively associated with SHCs controlled for all covariates, alongside a significant interaction effect of sex by school attendance. <b><i>Conclusions:</i></b> <b>The study shows a relatively stable level of SHCs in adolescents, with a minor increase in average levels over the 10 years investigated. Girls reported higher SHCs than boys and a curvilinear association was found between age and SHCs. The findings emphasize the significant influence of especially school-related stressors on adolescent SHCs.</b>