Aim: The aim of the current study was to investigate, in line with the 'Social Cure' tradition, whether identification with various groups (including the family, school and friends) predicted better psychological wellbeing amongst high school students. While previous research had shown there was a relationship between identification with these groups and mental health in adolescents, this work was cross-sectional, meaning that the direction of the relationship could not be established. The further aim of the current study was therefore to investigate these relationships over time. Method: Data were collected via self-report questionnaires from 409 pupils in several Scottish high schools. We measured students' mental wellbeing via the GHQ-12 questionnaire, as well as identification with their family, school and friend groups. Findings: Of the three groups investigated, only school identification predicted psychological wellbeing over time, indicating that educational practitioners are in a unique position to influence young people's mental health. Furthermore, the finding that school identification predicts mental health over time supports the theory presented in the social cure literature: that group identification predicts mental wellbeing. Limitations: A potential limitation was the use of self-report questionnaires. However, we feel that the strict policy of anonymity will have reduced socially desirable responses. Conclusion: The findings highlight the importance of the school for young people's mental health. Future research and interventions should consider the importance of identification with the school when attempting to enhance young people's mental wellbeing.