<p>As social media use has rapidly grown and widely been used, its association with depression has been increasingly documented. However, little is known about the relative association between social media use soon after waking versus total use and depression among adults. This study examines the associations between each of these independent variables and depression in a national sample of U.S. adults. We collected data from U.S. adults aged 30 to 70 years through surveys administered in July and August of 2023. Measures included social media soon after waking, total time spent on social media, seven sociodemographic characteristics, and depression using the Patient Health Questionnaire-9. The response rate was 61% (1512/2463). One-third of participants (33%) had depression. In separate survey-weighted multivariable logistic models, both total social media use and social media use soon after waking were significantly associated with depression. When both variables were included in the same model, only social media use soon after waking remained significantly associated with depression. Compared to almost no use soon after waking, frequent use after waking was associated with more than twice the odds of depression (Adjusted Odds Ratio = 2.05; 95% CI = 1.40, 3.00) after adjusting for total social media use and all covariates. The observed association may be bidirectional. Future studies should clarify the direction of these observed associations and determine whether modifying social media use soon after waking improves mental health outcomes or whether depressive symptoms increase engagement with social media upon waking.</p>