Introduction Heavy alcohol use is considered as a major public health issue1. Several risks factors have been identified, especially anxiety and depressive disorders. Yet, we know that these psychological disorders (1) have increased during the COVID-19 pandemic2 and (2) are more prominent during the transition to adulthood like a first-year university3. Therefore, we aimed to identify the prevalence and risk factors of alcohol use disorders (AUD) among first-year university students both before and during the COVID-19 pandemic. Material and methods Within the ADUC project (https://www.researchgate.net/project/ADUC-Alcool-et-Drogues-a-lUniversite-de-Caen-Normandie-Alcohol-and-Drugs-in-University-of-Caen-Normandy), 2247 first-year students completed an annual online survey between 2017 and 2020 measuring substances use variables, sociodemographic and psychological factors. To test the impact of COVID-19 pandemic on consumption, participants in years 2017-2019 were compared to participants in years 2020. Multinomial and binomial logistic regression models were performed. Results Regardless the COVID-19 pandemic, men were more likely to have severe AUD and to practice BD, smoking increases risks of moderate and severe AUD and BD, and depression increases the risk of severe AUD. Living with parents is a protective factor against severe AUD and BD. During the COVID-19 period, students were not more anxious and depressed than students in 2017-2019 years, and were less likely to use alcohol and to practice BD. Students who continued to drink were more likely to present severe AUD. Conclusions Our study highlights some common risk factors for substance use disorders among first-year university students prior to the COVID-19 period. Furthermore, while the health crisis appears to have been an additional risk factor for some user profiles, it may also have been a protective factor for others. The challenge of conducting future research on these different profiles will be discussed.