Aims: the aim of the present study was to examine changes over time in the relationship between self-reported school demands and psychosomatic problems, also considering the impact of student influence and teacher support. Methods: Data from a cross-sectional study (young in Värmland) including eight data collections (1988–2011) among Swedish students aged 15–16 were used (n = 20,115). Analyses with multinomial logistic regression and descriptive statistics were applied. Results: Between 1988 and 2011, the proportions of students with a higher degree of psychosomatic problems increased, as did the proportion of students experiencing school demands that were too high. Finer-level analyses based on stratification of student groups did not show any associations at the aggregated level between increases of school demands and psychosomatic problems. Similarly, individual level analyses showed that the strength of the association between school demands and psychosomatic problems was not affected by year of investigation. Conclusions:Changes in school demands over time could not explain the increasing trend in psychosomatic problems among adolescents. Since the relationship between school demands and psychosomatic problems is strong across time, there is, however, a continued need for school-based interventions. More studies are required to gain further understanding of adolescent mental health from a trend perspective.