Perceived Stress, Well-Being, and Academic Performance of University Students During the First COVID-19 Lockdown: A Study of Portuguese, Spanish, and Brazilian Students

<b>Background/Objectives</b>: The COVID-19 pandemic profoundly affected university students globally, exacerbating their already existing academic stress. This study investigates how the first COVID-19 lockdown (March-July 2020) differently impacted Portuguese, Spanish, and Brazilian university students' perceived academic stress, personal well-being, academic engagement, and performance. <b>Methods</b>: An online survey collected responses from 1081 university students (78.17% female; Mage = 25.43 years, SD = 9.27). Qualitative data on academic stressors were analyzed using content analysis. Cross-country differences were assessed through chi-square analyses and ANOVAs. Hypotheses were tested with a mediation path analysis. <b>Results</b>: Emotional distress emerged as the most prevalent stressor (54%). The results evidence differences in how students from the three countries experienced their academic life during the first COVID-19 lockdown. Personal and academic well-being mediated stress' effects on performance. <b>Conclusions</b>: These findings underscore the need for context-tailored interventions and proactive measures to support students' academic engagement in challenging contexts, informing educators and policymakers alike.