The impact of trauma on health and the moderating effects of social support : a study with the New Zealand police : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Psychology at Massey University
Traumatic experiences are an inherent part of many aspects of police work and the effects of trauma on police officers are of increasing concern to the New Zealand Police. There is evidence that social support following trauma may directly influence the development of adverse post traumatic stress reactions. Posttraumatic stress disorder (PTSD) is a specific psychiatric outcome of traumatic stress with a diagnosis (DSM-IV, American Psychiatric Association, 1994), which includes the traumatic experience as well as a constellation of symptoms. There is also evidence that additional physical health symptoms are associated with PTSD. Several factors have been explored as variables that could intervene between the traumatic experience and the development of symptoms and there is a growing body of empirical evidence for social support as an important factor. Horowitz' (1986) theoretical model of PTSD aetiology suggests that social support is a moderator of the experience of trauma in the development of stress reactions. The form of the interaction predicted by this model is known in the social support literature as the 'buffering hypothesis'. The primary aims of the present study were to extend the current evidence for the preventive role of social support in PTSD. Using a theoretical approach, it focused on the specific aspects of support which could buffer the stress\PTSD relationship. The theoretical model of PTSD, and the existing evidence, suggest that perceived emotional support, and in particular the opportunities to talk about the traumatic experience, are the salutary aspects of social support following trauma. It was hypothesised that aspects of emotional support such as opportunities to talk about trauma would moderate the relationship between traumatic experiences and psychological and physical health outcomes. The study also aimed to examine the prevalence of PTSD and physical health symptoms, and their relationship to the traumatic experiences of police officers. To meet these aims and test the hypotheses, 527 police officers in one geographical region of New Zealand were surveyed by questionnaire. Initial results showed that the prevalence of PTSD symptoms in the New Zealand Police is similar to that of other groups in the community who have suffered traumatic experiences. The wide range of traumatic experiences that were affecting the health of police officers were most likely to have occurred while they were at work. The results of regression analyses showed that the numbers of traumatic experiences were positively related to levels of posttraumatic stress disorder symptoms and physical health symptoms. The particular social support variables that moderated the effects of traumatic experiences on psychological and physical outcomes were: the ease of talking about trauma in the work place; the attitudes to expressing emotion; emotional support from peers; and emotional support from outside work. These results support the theoretical model of PTSD and social support that was tested in the study, and substantiate suggestions that, to buffer stress, the type of support must be specifically related to the needs elicited by the stressor. The results were further discussed in terms of the limitations of cross-sectional design, the measures used and suggestions for further research to confirm and extend the findings. The implications for police organisations were also discussed. These included the additive health effects of ongoing traumatic stress, the effects of other organisational stressors which must be taken into account, emotional support as an important factor intervening between traumatic experience and health outcomes, and the importance of support from peers and from family and friends which was highlighted in the present study.