BACKGROUND: Depression and anxiety are prevalent psychological challenges among patients with adolescent idiopathic scoliosis (AIS), affecting individuals across both sex and age groups. AIM: To explore the network structure of depression and anxiety symptoms, with a focus on identifying differences at the symptom level between sex and age subgroups. METHODS: A total of 1955 participants diagnosed with AIS aged 10-18 years were assessed using the Patient Health Questionnaire Depression Scale (PHO-9) and the Generalized Anxiety Disorder Scale (GAD-7), and 765 patients exhibiting PHQ-9 or GAD-7 scores ≥ 5 were enrolled in our study. Network analysis and network comparison tests were utilized to construct and compare the depression-anxiety symptoms networks among sex and age subgroups. RESULTS: The results revealed GAD3 "Excessive worry" and PHQ2 "Sad mood" were the most significant central symptoms in all subgroups, while "Sad mood" had higher strength than "Excessive worry" in the lower age group. In the network comparisons, the female network exhibited tighter connectivity, especially on GAD6 "Irritability" and GAD2 "Uncontrollable worry", while only PHQ3 "Sleep" and PHQ9 "Suicidal ideation" had differences at the local level in the lower age group. CONCLUSION: Several interventions targeting excessive worry and sad mood could reduce the risk of depression and anxiety symptoms in the AIS population. Furthermore, specific anxiety symptoms in females, along with sleep disturbances and suicidal ideation in the lower age group, should be addressed at an early stage to prevent significant disruptions in mental health trajectories.