<p>Social media has become the mainstream communication platform, offering unprecedented convenience, but its anonymity can also encourage negative interactions. This study investigates how negative comments on social media affect adults’ anxiety and mood. In an experimental study involving 128 adult participants (85 female, 43 male), individuals were asked to share blog posts on a simulated internet forum. Subsequently, they were exposed to either negative, neutral, or positive comments, and their mood and anxiety levels were measured using validated scales. Results showed that negative comments significantly increased anxiety and decreased mood compared to neutral or positive comments, while gender did not show any significant effects. Younger adults reported stronger anxiety responses to negative comments than older adults, suggesting heightened sensitivity among younger users. These findings highlight the psychological impact of negative social media comments on adults and underscore the importance of strategies for managing online negativity. This research expands our understanding of social media’s effects on adult mental health.</p>