BACKGROUND: The relationship between social media and mental health, particularly in youth, is an area of concern for researchers, clinicians, and parents. Rising rates of screen time have coincided with an increase in youth mental health issues, emphasizing the need to investigate the prevalence and clinical correlates of problematic social media use. METHODS: Our sample is a 489-participant sub-sample of the Texas Youth Depression and Suicide Research Network (TX-YDSRN) Registry, which is comprised of Texas youth receiving care for depression, suicidal ideation and/or suicidal behaviors. Prevalence of problematic social media use was identified, and indicators of mental and physical health were compared in those with or without problematic use. RESULTS: In our sample, 40.3 % of participants reported problematic social media use, and those with problematic use were more likely to report higher amounts of screen time. Relative to non-problematic users, problematic users endorsed more and higher depressive symptoms, anxiety, and suicidal thoughts, as well as poorer wellness factors. Participants with high duration and problematic use had poorer outcomes than those with low duration and non-problematic use. LIMITATIONS: The cross-sectional design does not allow for control comparisons and is limited by use of a single time point. Data are mainly derived from self-report measures, and generalizability of the findings may be impacted by overrepresentation of white females in the sample. CONCLUSIONS: As use increases, these data contribute to the empirical literature on the complex relationship between social media and mental wellbeing, suggesting problematic use is associated with poor mental health outcomes.