|Other Abstract||Posttraumatic stress disorder and depression are the most common psychological disorders to occur after people exploring a traumatic event. Due to the high incidence of comorbidity and its adverse clinical consequences, it is important to explore the etiological mechanism of the comorbidity of PTSD and depression and to find the key intervention targets. There are still controversies over the etiological hypothesis of PTSD and depression while the existing research on their comorbidity lacks studies of long-term longitudinal analysis or systematic symptom level analysis, without having the attention on children and adolescents. The current study adopted a long-term longitudinal design, starting the discussion from an overall perspective and then discussing in further details.
The first section of the study explores the developmental trajectory and mutual influence mode of PTSD and depressive symptoms among children and adolescents. The participants were 301 students from Beichuan County who had experienced the “512” Wenchuan earthquake (Mage = 12.5 years old, 52.2% were males). The whole investigation lasted for 4 years and were carried out at 4, 16, 29, 40 and 52 months after the earthquake. The study used UCLA-PTSD Reaction Index for DSM-Ⅳ and Children’s Depression Inventory for measurement, and used Latent Growth Mixture Modeling and Cross-Lagged Model as the tools of data analysis. The results showed that: (1) There were three trajectories of PTSD: resilience group (74.9%), recovery group (7.5%) and relapse group (17.7%); (2) depression had two trajectories resilience group (66.2%) and chronic group (33.8%); (3) PTSD and depression showed a mutually predictive pattern in the early stage after the disaster, while in the later stage, only depression predicted PTSD.
The second section of the study explored the evolution of the comorbid network structure of PTSD and depressive symptoms in children and adolescents from the perspective of the symptom network. Participants were 1,460 Zhouqu County students who had experienced Zhouqu debris flow (Mage = 12.9 years old, 47.7% were males).
The investigation lasted for 2 years from 3 months after the disaster, and the investigation was carried out at 3, 15 and 27 months. The measurements were the same as those in the first section, and the regularized partial correlation network was used as statistical method in this section. The results showed that: (1) Compared with the structure of the PTSD symptom network, the structure of the depressive symptom network was more stable. (2) Physiological cue reactivity, sleep problems and crying had a high level of expected influence in the comorbid network at the early stage. Physiological cue reactivity, detachments, concentration problems, sadness, self-depreciation, self-hatred and loneliness had high levels of expected influence in the comorbid network at the later stage. (3) Detachments, sleep problems, self-hate and loneliness had persistently high levels of betweenness in the comorbid network.
The third section of the study introduced the time dimension on the basis of the second section to explore the symptom action path in the comorbid network of PTSD and depression symptoms in children and adolescents. The participants and measurements were the same as in section 2, and the statistical method used a multilevel vector autoregressive model (mlVAR). The results showed that sleep problems, one of the overlapping symptoms of PTSD and depression, were the most predictive symptoms in the comorbid temporal network.
To summarize the findings of this paper, from an overall perspective, posttraumatic stress symptoms and depressive symptoms predicted each other in the early postdisaster stage, while only depressive symptoms predicted posttraumatic stress symptoms in the later stage. These results partially supported the interaction hypothesis in the comorbidity hypothesis. The trajectory analysis and the analysis of the evolution of the network structure of PTSD and depressive symptoms showed that the development of depression was more stable than the one of PTSD. This might be an important reason for the dominant role of depression in the later stage. From the perspective of the symptom network, the overlapping symptoms of PTSD and depression and the symptoms related to generalized emotional pain in depression maintain the connection between the two diseases. The analysis of the time network identified that sleep problems 3 months after the disaster have an important predictive effect on the symptoms in the comorbid network, suggesting the key role of traumatic sleep problems in the formation of long-term depression and PTSD. This article has important clinical implication. In the psychological intervention of children and adolescents after a disaster, PTSD and depression should be considered at the same time at the early stage, and persistent depressive symptoms should continue to be considered at the later stage. Meanwhile, attention should be paid to posttraumatic sleep problems in early clinical diagnosis to improve the sensitivity of diagnosis, thereby cutting off the long-term development of PTSD and depressive symptoms.|