Posttraumatic stress disorder among homeless adults in Sydney

Abstract

A number of international studies reveal high prevalence rates of posttraumatic stress disorder (PTSD) within homeless populations. Recent research on PTSD indicates that cognitive responses to trauma are critical in determining who develops the disorder. In Australia, a number of studies indicate exceptionally high rates of trauma experience among homeless adults, yet PTSD has not been investigated in this cohort. Therefore, the primary aim of this project was to improve understanding of PTSD and related cognitions in a sample of homeless adults in Sydney. The project attempts to determine the prevalence of PTSD and its onset in relation to homelessness (Study One) and also explores the role of cognitions in PTSD (Study Two). The sample consisted of seventy homeless men and women aged 18 to 73 years, who were randomly sampled through eight homeless services. A computer-assisted face-to-face structured clinical interview was conducted for each participant. The majority of the sample stated that they had experienced at least one traumatic event in their lifetime (98.2%). The twelve-month prevalence of PTSD was higher among homeless adults in Sydney in comparison to the Australian general population (41.1% versus 1.5%). In 59.1% of cases, the onset of PTSD was found to have occurred before the age of the first reported homeless episode. In a comparison of those with and without a current diagnosis of PTSD, it was found that those with PTSD scored significantly higher overall on measures of posttraumatic cognitions and early maladaptive schemas. In particular, this group scored higher on schemas that centre on the world being entirely dangerous and the self being totally inept. A mediational analysis showed that when trauma and mental health care were controlled, the relationship between early maladaptive schemas and PTSD symptom severity was mediated by posttraumatic cognitions. It was concluded that homeless adults in Sydney frequently experience trauma and PTSD, which typically precedes homelessness. It was also concluded that among homeless adults, posttraumatic cognitions and early maladaptive schemas appear to play an important role in PTSD and may be associated with symptom severity. These findings have implications for public policy on homelessness and mental health, homeless service provision, PTSD theory, and PTSD treatment for homeless adults.