Posttraumatic stress disorder (PTSD) symptoms are among the most prevalent mental health sequelae in children and adolescents following earthquakes. A recently introduced metric under network theories of psychopathology, network temperature, quantifies the global stability of a symptom network.

To examine the developmental trajectory of network temperature in children and adolescents after earthquakes, we established eight prospective cohorts (2–4 waves per cohort; total N = 5,794) after the Wenchuan, Yaan, and Jiuzhaigou earthquakes. We assessed PTSD symptoms across three postdisaster periods: early (≤2.5 years), middle (3.5–5.5 years), and late (8.5–10 years).

PTSD symptom network temperatures decreased across all eight cohorts. In the early post-Wenchuan period, adolescents declined more slowly than children. Across earthquakes, the early-period decline in children was faster after the Wenchuan earthquake than after the Yaan earthquake; for adolescents, the early-period decline rate followed the order Wenchuan < Jiuzhaigou < Yaan. Across post-earthquake periods, Wenchuan adolescents declined more slowly in the early period than in the middle/late period, whereas Yaan adolescents declined faster in the early period than in the middle period.

Across all earthquake types and post-earthquake periods, the PTSD symptom network system became increasingly stable and resistant to change. These findings underscore the necessity of early intervention alongside efforts to prevent deterioration. However, the rate of this decline varied by sample (children versus adolescents), earthquake, and post-earthquake period. Clinically, this calls for intervention strategies that are adjusted according to these factors.