Social media has become a part of the everyday activities of many people in the world. Individuals who habitually leverage social media to carry out more functions are referred to asnetizens. However, many of these people may have become addicted to the use of social media.This paper aims at a critical review of selected literature on the implications of addiction to social media on the mental health of these netizens. A systematic literature review approach was adopted to review the selected literature. Brief reviews are done on the meanings ofsocial media and mental health. The paper delved into the concept of social media addiction and the effects it has on the mental health of people using the Internet. Among the findings of this study are many netizens are addicted to the Internet and social media, and these addictions are affecting the mental health of netizens in many ways. It was concluded that the use of social media should be kept to a certain limit in order not to be addicted to it. It was, therefore, recommended that that various cadres of stakeholders should begin an aggressive awareness programme on the appropriate use of social media and the Internet so that people would not be addicted to the use of these modern technologies.