The role of posttraumatic stress disorder in explaining the psychosocial outcome of subarachnoid haemorrhage patients and their informal carers in both the short- and long-term

Abstract

Surviving subarachnoid haemorrhage (SAH) patients' experience significantly reduced health-related quality of life (HRQoL) in both the short- and long-term, as well as mysterious symptoms of fatigue and sleep dysfunction. Patients’ family members and friends - who often act as their informal carers - can also experience psychosocial disability. The cause for these poor outcomes remains unknown. Traditional explanations focusing on the neurological sequelae associated with SAH or the characteristics of the illness are not satisfactory; nor are attempts to explain family members' difficulties on the basis of carer burden. The hypothesis which is tested in this thesis is that post-traumatic stress disorder (PTSD) may be abnormally high in both the SAH patient and 'significant other' (SO) population and that this may explain their outcomes. SAH patients are known to be at risk of suffering from PTSD, but it is unknown if this explains their outcome. In terms of patients' SOs, they are known to experience psychiatric symptoms and I suggest these could be caused by their development of PTSD, but this has never been examined. In Part One (Chapter 2-5), I focus on patients' outcomes. Before examining my PTSD hypothesis, I present a meta-analysis (Chapter 2) I conducted of studies which have tried to explain patients' outcome using neurological factors. I conducted the meta-analysis as a tendency for prior studies to be underpowered and use unreliable statistics could have meant that the actual importance of traditional factors was obscured. The results of my meta-analysis however did not support this possibility and instead showed traditional neurological variables did not explain patients' outcome. With this in mind, I then present a longitudinal study (Chapter 5) in which I examined one of the largest prospective series of SAH patients to establish PTS D's explanative importance. Using regression analyses, this study showed PTSD was the best predictor for patients' mental HRQoL - the domain most persistently impaired. It also helped predict patients' physical HRQoL. Moreover, PTSD was linked to sleep problems and may therefore cause fatigue. Crucially, to establish the cause of PTSD, logistic regression was performed. This showed that maladaptive stress coping strategies were the best predictor for PTSD development. In Part Two of the thesis (Chapter 6), I present my longitudinal study of one of the largest prospective samples of SOs. All SOs were assessed with a diagnostic PTSD measure and coping skills were assessed. An elevated incidence of PTSD was found in both the short- and long-term. Although SOs' PTSD did not impinge on the recovery of the SAH patients being cared for, given that it is important to ensure SOs continue caring, regression results are presented which show the cause of SOs' PTSD was (at least in the short- term) due to the use of maladaptive coping strategies. The overarching conclusion is that the elevated incidence of PTSD in SAH patients and SOs helps explain why they experience psychosocial disability. In the final part of the thesis (Chapter 8) the clinical and theoretical implications of this conclusion are considered, such as that teaching patients and their SOs more effective coping skills might prevent PTSD and psychosocial disability.