Purpose: An important goal of McNally and colleagues’ study is to characterize the symptom structure of posttraumatic stress disorder (PTSD) using network analyses among survivors of the 2008 Wenchuan earthquake.
Background
Are the symptoms of mental disorders indicators of an underlying disease or are the symptoms themselves fundamental to the disease? In the case of a brain tumor causing dizziness and headaches, the concept of indicators seems very plausible. However, in mental disorders such as PTSD, it stands to reason that symptoms such as sleep disturbance and irritability may interact as if in a causal system, rather than being indicators of an underlying condition. The network approach takes these considerations into account.
Patients and methodology
Survivors of the 2008 Wenchuan earthquake were interviewed for the study (n=362). Study participants had lost a child or children in the disaster. Some of the respondents had been injured in the earthquake, had been buried under rubble, or had helped rescue others. Data collection occurred approximately 5.5 years after the earthquake. Various network analyses were conducted to characterize the structure of PTSD symptoms.
Results
Key findings include that hypervigilance occupied a significant position in the symptom structure, as did feelings of a restricted future. In addition, there was evidence that associations between symptoms in the network may be bidirectional. Furthermore, significant associations were found between irritability/rage outbursts and sleep as well as irritability/rage outbursts and concentration problems.
Conclusions of the authors
The results provide preliminary evidence of a possible causal structure of PTSD using a sample of earthquake survivors, although the data are cross-sectional. Network analysis represents a promising method for characterizing the symptom structure of mental illness. The results partially support the structure of the symptom clusters according to DSM-IV. The authors see the central position of hypervigilance in the network in accordance with the understanding of PTSD as a disorder that is significantly characterized by the experience of a permanent threat.
Comment
Viewing mental disorders such as PTSD from a network perspective offers a valuable opportunity for optimizing diagnosis and therapeutic interventions. It would be of great interest to know what differences exist in the symptom structure of PTSD as a result of different traumas such as natural disasters and interpersonal trauma. In addition, information from network models on the dominance of specific symptoms and their change over the course of treatment could contribute to a better understanding of change processes and in this way enable improvement of treatments. In terms of personalized medicine [1], this could in the long run allow individual adaptation of therapeutic interventions to patients with specific network characteristics. Furthermore, network analyses could also provide valuable information with regard to the symptom structure of PTSD according to DSM-5.
Literature:
- Insel TR: Translating scientific opportunity into public health impact: a strategic plan for research on mental illness. Archives of General Psychiatry 2009; 66(2): 128-133.
InFo NEUROLOGY & PSYCHIATRY 2016, 14(1): 18.
