ENThe current two-wave longitudinal study aimed to investigate changes in stress, anxiety, depression, and positive mental health (PMH) during the first COVID-19 pandemic outbreak in the sample of emerging adults. Data were collected before the COVID19 and within the first month of the outbreak. The study sample consisted of 775 university students from Lithuania (n ¼ 450, Mage(SDage) ¼ 19.45 (0.93), 79.3% female) and Germany (n ¼ 325, Mage(SDage) ¼ 23.08 (2.94), 78.2% female). The results of multivariate Latent Change Analysis revealed that Lithuanian and German emerging adults demonstrated a decrease in stress and anxiety at the COVID-19 outbreak. Lithuanians also showed a decrease in depressive symptoms and an increase in PMH. Three groups with different change patterns were identified: resilient (82%) demonstrating positive changes, high-symptom (8%) with stable high rates of stress and depression and stable low rates of PMH, and vulnerable (10%) with an increase in depressive symptoms as well as a decrease in PMH over time. Keywords: COVID-19, young adults, stress, anxiety, depression, mental health. [From the publication]