Pre- and post-disaster negative life events in relation to the incidence and severity of post-traumatic stress disorder.

There is evidence suggesting that stressful life events may precede major psychiatric illness, such as major depression, and that the severity of a traumatic event outside the range of usual human experience may provoke post-traumatic stress disorder (PTSD). The present study was carried out to examine the effects of pre- and post-disaster stressful life events on the incidence rate of PTSD following two man-made traumatic events. An epidemiological study examining 127 victims of a flash fire in a ballroom and 55 motor vehicle accident (MVA) victims was undertaken. PTSD symptoms were assessed by means of the Composite International Diagnostic Interview and the pre- and post-disaster stressful life events by means of the Diagnostic Interview Schedule, Disaster Supplement. Binary logistic and multiple linear regression analyses were employed to examine the relationships between PTSD and pre- and post-disaster life events. There were no significant relationships between stressful life events the year prior to the traumatic event and the incidence or severity of PTSD. There were highly significant relationships between the cumulative number and event severity of post-disaster negative life events and the incidence rate and severity of PTSD. The post-disaster life events were significantly more related to the avoidance-depression dimension than to the anxiety-arousal dimension of PTSD. The most significant life events were: loss of job or income, broken relationships, serious illnesses or injuries in the victims and death or illness in close acquaintances. The results of this study show that the number and severity of additional stressful life events signal a higher risk to develop PTSD and a higher severity of the avoidance-depression dimension of PTSD symptomatology.