Comorbidity of posttraumatic stress disorder and depression among adolescents following an earthquake: A longitudinal study based on network analysis

High comorbidity between posttraumatic stress disorder (PTSD) and depression among adolescents often follows severe traumatic events. Models on the pathway to comorbidity dispute greatly and how PTSD and depression get comorbidity, remain unclear.A follow-up investigation was conducted of 424 adolescent survivors of the Jiuzhaigou earthquake at 12 months (T1) and 27 months (T2).Contemporaneous network analysis and cross-lagged panel network analysis showed that PTSD and depression are two separate disorders with strong associations via links between dysphoric symptoms of PTSD and somatic or non-somatic symptoms of depression. However, the association weakened from T1 to T2, and internal connections between symptoms within each disorder became stronger.We only measured the comorbidity of PTSD and depression at two time points following the earthquake, which may limit the long-term applicability of our findings following trauma.The findings also showed that the centrality in contemporaneous networks may indicate node connectivity rather than the influence or potential causality among nodes. These results help to elucidate the relationship between PTSD and depression and could contribute to the development of appropriate therapies.