Background/Objectives: Short video addiction (SVA) has become a matter of public health concern, impacting the well-being of college students. However, previous studies have largely treated SVA as a homogeneous phenomenon, overlooking the potential heterogeneity in addictive behaviors among individuals and their underlying mechanisms. This study aims to identify distinct SVA subtypes and explore the mediating role of inattention (IA) in the relationship between these subtypes and negative emotions. Methods: The present study recruited a sample of college students through a multicentre online survey conducted from January to August 2025. Latent profile analysis identified distinct SVA categories among college students, and further examination of the mediating role of IA between SVA and negative emotions (anxiety, depression) was undertaken. Results: Latent profile analysis stratified SVA into three cohorts: “Healthy short video use” (8.9%), “Short video dependence” (55.8%), and “Short video addiction” (35.3%). The subtypes differed in levels of IA, anxiety, and depression (p < 0.05), with IA functioning as the link between SVA and negative emotions. It is noteworthy that IA demonstrated a complete mediating effect in the anxiety model, thereby indicating that the adverse impact of SVA on mental health is predominantly mediated by impaired attention function. Conclusions: This study deepens the understanding of students’ SVA from a heterogeneity perspective and provides empirical evidence for exploring the potential cognitive mechanisms through which SVA influences mental health. It is suggested that targeting attention function may hold great value in alleviating SVA-related psychological issues.

Background: Early childhood caregivers are exposed to intensive caregiving demands and have a high risk of depression. Guided by the family stress process model and Acceptance and Commitment Therapy (ACT), this cross-sectional study examined whether psychological flexibility mediates the association between parenting stress and depression. Methods: A cross-sectional survey was conducted among 1140 Chinese primary caregivers of infants aged 0–36 months in Ya’an, Sichuan, China, from 9 October 2022 to 8 October 2025 using convenience sampling. Validated scales included the Parenting Stress Index-Short Form (PSI-SF), Acceptance and Action Questionnaire-II (AAQ-II) (Higher AAQ-II scores reflected lower psychological flexibility), and Patient Health Questionnaire-8 (PHQ-8). Hayes’ PROCESS Model 4, with 5000 bootstrap resamples, was adopted for the mediation analysis. Results: Parenting stress was positively associated with depressive symptoms (r = 0.335, p < 0.01) (weak-to-moderate effect size). Psychological flexibility exerted a partial mediating effect between the two variables, and the indirect effect accounted for 45% of the total effect. Caregivers with lower household income, lower educational level, and those caring for children aged 0–12 months reported significantly higher depression (all p < 0.05). Conclusions: Parenting stress is an important risk factor for depression, and psychological flexibility plays a significant partial mediating role in this relationship. ACT-based interventions targeting psychological flexibility may hold implications for depression among early childhood caregivers.