To examine the prevalence of 12-month mood disorders and receipt of mental health treatment among a volunteer sample of higher education students during the 2nd and 3rd COVID-19 wave in the Flanders region. Web-based self-report surveys were obtained from 9101 students in higher education in the Flemish College Surveys (FLeCS) in Flanders, Belgium. As part of the World Health Organization's World Mental Health --International College Student Initiative, we screened for 12-month mood disorders (major depressive episode (MDE), mania/hypomania), and service use. We used poststratification weights to generate population -representative data on key socio-demographic characteristics. 50.6% of the respondents screened positive for 12-month mood disorders (46.8% MDE, of which 22.9% with very severe impact). Use of services was very low, with estimates of 35.4% for MDE, 31.7% for mania, and 25.5% for hypomania. Even among students with very severe disorders, treatment rates were never higher than 48.3%. Most common barriers for not using services were: the preference to handle the problem alone (83.4%) and not knowing where to seek professional help (79.8%). We found a high unmet need for mood problems among college students; though caution is needed in interpreting these findings given the volunteer nature of the sample. A reallocation of treatment resources for higher education students should be considered, particulary services that focus on innovative, low-threshold, and scalable interventions.