The transition to adulthood is a critical period for mental health, yet limited evidence exists on how family structure and sociodemographic contexts are associated with depressive symptoms and psychological distress.

This cross-sectional study used data from the Spatial Social Networks and Environmental Exposure (SSNE) Project to examine associations between single parenting, sociodemographic characteristics, and mental health outcomes among 2446 young adults in the United States. Mental health was assessed using the Patient Health Questionnaire-9 (PHQ-9) and the Depression, Anxiety, and Stress Scale (DASS-21). Chi-square tests were used to examine bivariate associations, and survey-weighted multivariable linear regression models were applied to assess associations between explanatory variables and mental health outcomes.

Overall, 16.62% of participants reported being raised in single-parent households. Approximately 60.25% of participants fell into moderate-to-severe categories of depression (PHQ-9), and 71.08% reported moderate-to-extremely severe psychological distress (DASS-21). In weighted regression models, single parenting was not significantly associated with depressive symptoms or psychological distress. Younger age, Hispanic ethnicity, and sexual minority status were significantly associated with higher mental health symptom scores. Notably, Black participants had higher depressive symptom scores, while Asian participants showed lower psychological distress. In stratified analyses, socioeconomic disadvantage and younger age were more consistently associated with poorer mental health among minority participants, whereas associations with family structure were not statistically significant across groups.

Sociodemographic factors, including socioeconomic disadvantage, minority identity, and younger age, were consistently associated with mental health outcomes among young adults. The association between single-parent family structure and mental health outcomes was not statistically significant in weighted analyses, highlighting the importance of cautious interpretation. These findings underscore the need for interventions that address broader social and economic determinants of mental health.