Journal of Contextual Behavioral Science (JCBS)
Volume 39, January 2026
Authors
Dmytro I. Boiko & Anastasiia D. Shkodina
Key Findings
- Combatants with PTSD show lower psychological flexibility and higher rigidity.
- AdjD associated with intermediate flexibility but high psychological rigidity.
- Key distinguishing factors are present moment, cognitive fusion and inaction.
- Acceptance and experiential avoidance similar across all combatant groups.
- Targeted psychological flexibility may be beneficial for military mental health.
Abstract
This observational cross-sectional study examined psychological flexibility and rigidity in Ukrainian military personnel participating in the Russian-Ukrainian war. A total of 129 male combatants were divided into three groups: those with posttraumatic stress disorder (PTSD, n = 63), those with adjustment disorder (n = 36), and a control group without mental disorders (n = 30). Psychological flexibility and rigidity were assessed using the Multidimensional Psychological Flexibility Inventory (MPFI). Results demonstrated that combatants with PTSD exhibited the lowest psychological flexibility and highest psychological rigidity compared to the control group. Participants with adjustment disorder showed intermediate levels of psychological flexibility between the PTSD and control groups, while maintaining elevated psychological rigidity comparable to the PTSD group. Significant differences were observed across all components of psychological flexibility and rigidity except for acceptance and experiential avoidance, which were similar across all groups. Notably, combatants with PTSD showed significantly higher levels of cognitive fusion and inaction compared to those with adjustment disorder. These findings highlight psychological flexibility as a potential therapeutic target for military personnel with stress-associated mental disorders and suggest that targeted interventions enhancing specific psychological flexibility components may constitute an efficacious approach to addressing combat stress sequelae.