Research has shown that young adults were more vulnerable to mental health issues during the COVID-19 pandemic. However, the mechanism of the effect of COVID-19-related stress on mental health outcomes among young adults is still unclear. In general, COVID-19-associated anxiety and depression have been reported in adults. The aim of this study was to investigate the effects of stress associated with COVID-19 pandemic and mental health outcomes. Studies show that the direct effects of stress due to social distance problems on anxiety and depression are much greater than the stress caused by fear of infection and anger compared to others. The results indicate that interventions to increase social support and resilience can be effective strategies to reduce the risks of anxiety and depression among young people with stress caused by social distancing problems.