IntroductionDespite extensive research on social media and risks for mental health, not enough is known about individual differences in these risks.MethodsThe present study, with data collected from 2018 to 2020, investigated the association between social media use (total and for specific platforms) and depressive symptoms in a sample of 237 American adolescents (Mage = 15.10; SD = 0.49; 51.1% girls and 48.5% boys). We investigated several moderators: gender, self‐esteem, personality, and negative reactions to social media. Covariates were gender, timing of the follow‐up (pre vs. during the pandemic), and depressive symptoms a year earlier.ResultsResults indicated that greater total time spent on social media was associated with higher levels of depressive symptoms. This effect held for Instagram, TikTok, and YouTube (but not Snapchat, Facebook, or Twitter). Several moderated effects were found. Twitter was associated with more depressive symptoms for girls but not boys. More frequent Instagram use was linked to more depressive symptoms for less or average‐level extraverted teens but not for more extraverted teens, suggesting extraversion may be protective. More frequent TikTok use was associated with more depressive symptoms, particularly for teens who said they have more or average‐level negative reactions to social media a year earlier.ConclusionsThis study suggests that certain adolescents may be at increased risk for serious mental health challenges, like elevated depressive symptoms, when using TikTok, Instagram, or Twitter more frequently, underscoring the importance of examining individual differences and particular social media platforms.