This research explored the dark side of social media use among Gen Z during the first pandemic lockdown in the UK and adds to empirical evidence of the devastating effect of the COVID-19 pandemic on young people 's mental health . Using the S - O - R framework , this study reveals the detrimental effect of COVID-19 information overload on social media that resulted in Gen Z social media users ' psychological ill - beingsocial media fatigue and fear of COVID-19 . Both social media fatigue and fear of COVID-19 motivated Gen Z to disengage from social media and translated perceived information overload into social media users ' discontinuance intention . However , as social media is considered the main means by which members of Gen Z maintained contact with each other during the lockdown , FoMO was seen to buffer the impact of social media fatigue and fear of COVID-19 on Gen Z 's social media discontinuance intention . Our research provides unique and original evidence demonstrating the psychological mechanism associated with Gen Z 's social media use during the outbreak of the COVID-19 pandemic in the UK and advances understanding of the ' side effects ' of COVID-19 from social and psychological perspectives . We also highlight a series of practical implications for social media users , social media platform providers , and health officials , institutions , and organizations to consider in using social media in a more effective and sustainable manner during a global pandemic and in the post - pandemic time . The present study has several limitations , such as utilizing cross - sectional data and focusing on one age group and one country during the initial pandemic phase . However , in light of the continuing pandemic , such limitations also have important implications for avenues of future work .