A Longitudinal Investigation of the Impact of Operational Deployment on the Psychological Wellbeing of New Zealand Defence Force Service Personnel
The deleterious impact of combat on psychological wellbeing has been documented as early as 490 B.C. by Greek historians (Bentley, 2005), and researchers continue to delve into this phenomenon today. Published literature in this field largely emanates from the United States and United Kingdom, whilst research from New Zealand is largely absent. The current study seeks to fill this gap with an investigation of the impact of overseas deployment on the psychological wellbeing of New Zealand Defence Force (NZDF) military personnel. This study utilised data from 1410 NZDF military personnel who operationally deployed between 1 July 2015 and 31 October 2016 and completed two questionnaires: (1) immediately following deployment, and (2) six months after returning home. Regression, moderation, mediation, and path model analyses were used to analyse the data. Several key findings were obtained. Firstly, combat stressors, as expected, predicted posttraumatic stress disorder (PTSD) symptoms but surprisingly not psychological distress. PTSD, as expected, predicted distress. Secondly, moderation analysis revealed that experiencing medium to high levels of non-combat stressors in addition to combat stressors was likely to result in exacerbated levels of PTSD symptoms. Thirdly, demographic characteristics such as being in the Navy, being female, and not being in a relationship were all identified risk factors for poorer psychological outcomes (PTSD symptoms and psychological distress), whereas neither ethnicity nor prior deployment experience functioned as risk factors. Lastly, mediation analysis revealed that PTSD partially explained the relationship between combat events and posttraumatic growth, suggesting that PTSD symptomology may prompt military personnel to appraise outcomes from their deployment, and subsequently experience personal growth. Implications of the current research lay in the potential for improvements to be made to the education, training, and support offered by the NZDF to their service personnel.