Objective: In March 2020, the emergence of COVID-19 as a pandemic prompted large scale, social lockdowns internationally. Participants/Method: Here, we compared the mental health symptoms and social functioning of pre-pandemic college students collected during the Spring 2020 semester to those of a pandemic group collected during the Fall 2020 semester. Results: Results reveal that students assessed during the pandemic reported more severe symptoms of posttraumatic stress and depression, yet no difference in anxiety symptoms, relative to students assessed before the pandemic. Furthermore, students assessed during the pandemic conceptualized and categorized their emotions with significantly more neutral emotions and significantly fewer positive emotions, yet no difference in negative emotions, relative to students assessed before the pandemic. Despite these mental health effects, we found no difference between the two groups in self-reported social functioning. Conclusion: Overall, these results suggest young adults' mental health was significantly impacted by the pandemic, with the potential for long lasting effects.