Comprehensive Assessment of Combatants' Psychological and Psychophysiological State in Exposure Therapy of Post-Traumatic Stress Disorder Using Virtual Reality

The aim of the study was to develop the rehabilitation technology that enables the monitoring of psychophysiological stress markers during exposure therapy of post-traumatic stress disorder in combatants using virtual reality (VR). Materials and Methods. The study involved 69 men: 31 combatants (mean age - 35.61 +/- 9.13 years) and 38 healthy research subjects - a control group (mean age - 24.68 +/- 5.71 years) not engaged in active combat. Post-traumatic stress disorder was diagnosed using Structured Clinical Interview for DSM and Mississippi Scale. We suggested an original hardware and software system for exposure therapy in VR. Stimulus material included a number of virtual scenes: three combat scenes and a non-combat one. Heart rate variability was recorded to control a patient's state during the session. As markers of stressogenic situations we used CS-index (suggested by S.V. Bozhokin), as well as the indices of functional reserve and tension degree of the regulatory systems (according to R.M. Baevskiy). Results. There were revealed three main responses on VR scenes with an original content. The three variants were called as follows: "anxious", "neutral", and "inverse". The suggested methodology enables to continuously monitor psychophysiological parameters during a certain session, and analyze their dynamics within a therapy course. Using calculated indicators by Baevsky makes it possible to classify combatants by adaptive potential at the beginning and at the end of the exposure therapy course in VR; make use of online-control of a patient's functional state in virtual environment, and create conditions for controlled information influence (CS-index by Bozhokin). The preliminary results presented in the study are promising regarding the possibility to choose a personalized program of rehabilitation measures for each response type using a developed hardware and software system. Biological feedback on heart rate variability included in hardware and software system will contribute to train and harness a patient's habit of an operative independent correction of the patient's state.