Discrimination and the risk of depression among university students: A national longitudinal study using diagnostic data

Abstract

Objective: Discrimination is increasingly recognized as a key risk factor for student mental health. However, few longitudinal studies have assessed its association with clinically defined depression using standardized diagnostic tools. This study examines whether self-reported experiences of discrimination are associated with an increased risk of major depressive episode (MDE) one year later among higher education students.

Participants: A subsample of 7884 university and college students (ages 18-35) from the national Norwegian SHoT2022 survey who completed a self-administered follow-up diagnostic interview one year later.

Methods: Discrimination was assessed at baseline across ten domains (e.g., ethnicity, gender, sexual orientation, political opinion). Current MDE was assessed using the electronic version of the Composite International Diagnostic Interview (CIDI 5.0). Poisson regression with robust standard errors was used to estimate relative risks (RRs), adjusting for age, sex, and baseline psychological distress.

Results: Discrimination was commonly reported, with gender-based discrimination most prevalent among women and political discrimination among men. Exposure to any discrimination was associated with an elevated risk of MDE (RRs ranging from 1.3 to 2.9), with sexual orientation- and gender identity-based discrimination showing the strongest effects. A clear dose-response relationship was observed: students reporting four or more types of discrimination had a nearly fourfold risk of MDE compared to those reporting none. Associations were generally similar across sexes.

Conclusions: Discrimination is a robust and graded predictor of depression among students in higher education. Findings underscore the need for inclusive mental health services and institutional efforts to prevent and address discrimination on campuses.

Keywords: CIDI; Depression; Discrimination; Longitudinal study; Mental health; University students.