The research results presented in this publication indicate that during the COVID19 epidemic, there were significant changes in the use of the Internet and social media among the youth population in Belgrade. The study was conducted on a sample of 500 respondents aged 18 to 30 who were in the city of Belgrade before and during the pandemic. Indicators of social media addiction were significantly increased in this population, especially during the state of emergency in 2020. Also, a statistically significant correlation was observed between the indicators of internet addiction, and the levels of depression, anxiety and mental distress. During this extensive study, we proposed several guidelines and recommendations for the modification and improvement of current public health policies in order to preserve and improve the mental health of young people, and prevent mental disorders.