Background <p>This study aims to examine the association between interpersonal competence (IC) and depressive symptoms among soldiers of the Chinese People's Armed Police (PAP).</p> Methods <p>A combined cross-sectional and longitudinal approach was used to examine the association between IC and depressive symptoms. In this cross-sectional study, a total of 3,174 male soldiers completed mental health scales. The Brief Interpersonal Competence Questionnaire (ICQ-15) and Patient Health Questionnaire (PHQ-9) were chosen to assess the participants’ interpersonal competence and depressive symptoms. A three-wave longitudinal study involving 300 PAP recruits was conducted over a three-month period. Cross-lagged analysis was conducted via M-plus software, and network analysis was performed in R.</p> Results <p>Cross-sectional network analysis revealed that emotional support and initiation nodes served as the core nodes in the network, conflict management served as a key bridge node connecting the interpersonal functioning dimension with depressive symptoms. A cross-lagged panel model(CLPM) analysis indicated that time 1 interpersonal competence (IC) negatively predicted time 2 depressive symptoms, and time 2 IC negatively predicted time 3 depressive symptoms. The cross-lagged panel network analysis further showed that conflict management was the node that negatively predicted depressive symptoms most strongly during T1–T2, whereas both self-disclosure and conflict management negatively predicted subsequent depressive symptoms during T2–T3.</p> Conclusions <p>This study integrates cross-sectional network and longitudinal cross-lagged analyses to clarify the association between IC and depressive symptoms. In this cross-sectional study, emotional support and initiation were identified as core nodes of interpersonal competence, conflict management was identified as the key bridge node connecting IC to depressive symptoms. In longitudinal cross-lagged analysis (CLPM), IC negatively predicted depressive symptoms across time points, Cross-lagged panel network analysis further revealed that conflict management negatively predicted depressive symptoms most strongly from T1 to T2, whereas both self-disclosure and conflict management negatively predicted subsequent depressive symptoms from T2 to T3.These findings reveal the effect of IC&#xa0;on&#xa0;depression and provide an important foundation for subsequent psychological interventions.</p>