Mapping Sex Differences in Depression, Anxiety, and Co-Occurring Symptoms in Adults Under Stress: A Bayesian Network Approach.

BACKGROUND: Sex differences in the prevalence and presentation of depression and anxiety are well-established, yet disparities in the underlying network structure and potential causal relationships between symptoms, particularly under significant stress, remain less understood. Understanding these network differences is crucial for elucidating mechanisms and tailoring interventions. This study explored sex differences in the network structure of depression, anxiety, and co-occurring symptoms (posttraumatic stress disorder [PTSD] symptoms, insomnia, and fear reactions) in an adult population. METHODS: A cross-sectional survey was conducted among adults (N = 1,191, 684 women, aged 18-40) in Shanghai during a period of significant acute public health stress (pandemic citywide lockdown). Participants reported symptoms of depression (Patient Health Questionnaire [PHQ]), anxiety (Generalized Anxiety Disorder [GAD]), PTSD (intrusion, avoidance), insomnia (Insomnia Severity Index [ISI]), and fear reactions. Partial correlation networks examined overall symptom connectivity. Bayesian network (BN) analysis generated directed acyclic graphs (DAGs) to infer potential directional dependencies. Analyses were conducted by sex. RESULTS: Distinct sex-specific symptom network patterns emerged. Anxiety and intrusion symptoms were most central for women, while depression was most central for men. Overall network connectivity was significantly higher in women. Critically, BN analysis identified a more complex architecture of probabilistic dependencies in women, evidenced by a greater number of directed edges compared to men. The men's DAG indicated a relatively sparse structure with fewer directional pathways between symptoms. CONCLUSIONS: Men and women exhibited distinct distress symptom network structures under acute stress. Specifically, anxiety and intrusion emerged as central nodes in women, indicating that they may represent promising intervention targets to prevent symptom escalation, while depressive symptoms were more central to men. These findings highlight the importance of sex-sensitive psychological first aid during public health crises and establish an empirical foundation for the development of sex-informed, process-oriented interventions in future research.