2.1 Diagnosis and Conceptual Framework of Post-Traumatic Stress Disorder
The diagnostic conceptualization of post-traumatic stress disorder (PTSD) has continuously evolved alongside revisions of the Diagnostic and Statistical Manual of Mental Disorders (DSM). With the release of DSM-5, the symptom clusters of PTSD were restructured from the three-factor model in DSM-IV—re-experiencing, avoidance/numbing, and hyperarousal—into a four-factor model comprising intrusion symptoms, persistent avoidance, negative alterations in cognitions and mood (NACM), and marked alterations in arousal and reactivity (AAR) (Armour et al., 2015; Foa et al., 2015).
Regarding the latent factor structure of PTSD, multiple theoretical models have been proposed. Armour et al. (2015) used confirmatory factor analysis (CFA) based on DSM-5 symptom criteria and supported the Hybrid Anhedonia and Externalizing Behaviors model. This seven-factor model further decomposes the four DSM-5 symptom clusters into intrusion, avoidance, negative affect, anhedonia, detachment, hyperarousal, and reckless or self-destructive behavior. Additionally, a cross-cultural, multi-site study demonstrated the replicability and generalizability of the PTSD symptom network structure, suggesting relative stability of symptom organization across populations and cultural contexts (Fried et al., 2018). To facilitate assessment under the DSM-5 framework, Foa et al. (2015) developed and validated the Posttraumatic Diagnostic Scale for DSM-5 (PDS-5), providing a psychometrically sound instrument for both clinical practice and research applications.
2.2 Epidemiology and Comorbidity of PTSD
Exposure to traumatic events is highly prevalent worldwide; however, only a proportion of exposed individuals subsequently develop PTSD. Findings from the World Mental Health Surveys indicate that the lifetime prevalence of PTSD varies substantially across countries and trauma types, highlighting sociocultural differences in vulnerability and risk (Kessler et al., 2016; Koenen et al., 2017).
High rates of psychiatric comorbidity are a defining clinical characteristic of PTSD, with anxiety and depressive disorders being the most common co-occurring conditions. These patterns indicate that traumatic experiences elicit persistent fear and avoidance responses and disrupt emotional regulation and cognitive functioning. During the COVID-19 pandemic, numerous studies reported that individuals exhibiting PTSD symptoms frequently experienced concurrent anxiety and depressive symptoms (Kar et al., 2021; Liu et al., 2020; Liu et al., 2021; Sun et al., 2021; Sousa et al., 2021). Similarly, intensive care unit (ICU) survivors exposed to prolonged social isolation and uncertainty display comparable psychological burdens, including intrusive recollections, sleep disturbances, helplessness, and persistent depressive symptoms during recovery (Hatch et al., 2018; Parker et al., 2015). These comorbid conditions hinder psychological and physical recovery and substantially increase the complexity of clinical management.
2.3 Risk and Protective Factors Associated with PTSD
The development of PTSD is a multifaceted process resulting from the interaction of multiple risk and protective factors, rather than a single causal pathway. From a biological perspective, genetic factors are critical. PTSD, major depressive disorder (MDD), and anxiety disorders exhibit moderate heritability and share stress-related genetic vulnerability (Smoller, 2016).
At the social level, environmental factors are essential. For instance, social support networks have been shown to reduce the risk of developing PTSD, as evidence indicates that higher social support predicts lower PTSD symptoms over time (Wang et al., 2021). In contrast, sustained or occupation-specific stressors can increase PTSD risk. Among frontline healthcare workers, moral injury and occupational burnout are closely associated with PTSD symptoms. During the early phase of the COVID-19 pandemic, frontline medical personnel who experienced moral distress exhibited significantly greater PTSD symptom severity, burnout, and psychosocial dysfunction (Norman et al., 2021; Restauri & Sheridan, 2020).
2.4 PTSD Research in Specific Traumatic Contexts
The COVID-19 pandemic is a global health crisis and traumatic stressor (Bridgland et al., 2021), profoundly affecting mental health. Studies in China (Sun et al., 2021), Italy (Forte et al., 2020), and the US (Liu et al., 2020; Liu et al., 2021) found significant increases in PTSD symptoms. Subgroups especially affected include young adults, single people, those with higher education, and students (Kar et al., 2021; Liu et al., 2020). In perinatal women, grief and COVID-19-related health worries were key risk factors for depression, anxiety, and PTSD (Liu et al., 2021).
For patients who survive critical illness and intensive care unit (ICU) treatment, the experience may constitute a lasting psychological trauma. Research on ICU survivors indicates that many continue to experience PTSD symptoms after discharge, which are associated with memory gaps, traumatic recollections, and specific physiological or treatment-related factors encountered during ICU hospitalization (Parker et al., 2015). Notably, elevated rates of anxiety, depression, and PTSD persist up to one year following ICU discharge (Hatch et al., 2018).
Childbirth may also represent a traumatic experience for some women. Prenatal depressive symptoms, intense fear of childbirth, pregnancy-related complications, pre-existing PTSD, or prior engagement in psychological counseling strongly predict the development of childbirth-related PTSD in the postpartum period (Ayers et al., 2016).
Among military veterans, traumatic brain injury (TBI) has been identified as a potential contributor to the development of psychogenic nonepileptic seizures (PNES). Mild TBI is highly associated with PNES diagnoses, and PTSD may play a critical moderating role in the progression from TBI exposure to PNES manifestation among veterans (Salinsky et al., n.d.).
2.5 Emerging Trends in PTSD Treatment
In the treatment of PTSD, cognitive behavioral therapies (CBT), particularly Prolonged Exposure (PE) and Cognitive Processing Therapy (CPT), are widely regarded as gold-standard interventions. Nevertheless, ongoing research continues to explore novel therapeutic approaches, as a substantial proportion of patients do not achieve full remission following first-line treatments (Burback et al., 2024).
Mindfulness-based interventions have been studied as adjunctive or alternative treatments for PTSD, though meta-analyses indicate mixed outcomes and variability in the quality and types of interventions reviewed (Mindfulness-Based Interventions for Psychological Trauma and Posttraumatic Stress Disorder (PTSD), 2025). Approaches such as mindfulness-based stress reduction and mindfulness-based cognitive therapy demonstrate relatively low dropout rates and moderate to large treatment effects in PTSD populations. Mindfulness interventions may provide therapeutic benefits by regulating emotional under- or over-modulation, processes central to PTSD symptomatology. Additionally, these interventions may facilitate the restoration of large-scale brain network connectivity, including interactions among the default mode network, central executive network, and salience network (Boyd et al., 2018).