Information updating and autobiographical memory in posttraumatic stress disorder

Cognitive theories suggest that information updating and autobiographical memory characteristics may play a role in the development and maintenance of PTSD symptoms (e.g., Ehlers & Clark, 2000). This thesis presents five studies that examine memory updating of negative and neutral associated memories, negative and positive appraisals about strangers, and disorganised trauma memories in posttraumatic stress disorder (PTSD). Study 1 demonstrated that low mood but not anxiety tended to be associated with difficulties with updating negative compared to neutral associative memories (Chapter 2). Study 2 found that relative to a sample of control participants, people with PTSD had difficulties with updating neutral compared to negative associative memories. Updating performance for neutral material was related to changes in memory characteristics with PTSD treatment (Chapter 3). Study 3 demonstrated that compared to controls, trauma survivors with PTSD showed more change in negative appraisals about strangers with negative information, compared to change in positive appraisals with positive information. Interpersonal distressing events in both groups tended to be associated with difficulties in updating appraisals about strangers (Chapter 4). Study 4 demonstrated that compared to controls, trauma survivors with PTSD reported poorer memory recall and more memory disjointedness of their traumatic event, but not of a negative control event. Poor recall and memory disjointedness improved with PTSD treatment (Chapter 5). Study 5 demonstrated that in healthy participants, exposure to a trauma film led to more disjointed memories of the film compared to exposure to a neutral film. Memory disjointedness partly mediated the relationship between peri-traumatic cognitive processing and re-experiencing symptoms after trauma film exposure (Chapter 6). The findings provide support for the cognitive model of PTSD (Ehlers & Clark, 2000), and suggest that difficulties in updating neutral information, the development of negative appraisals, and poor memory recall and memory disjointedness of trauma memories may contribute to the maintenance of PTSD symptoms.