Ethnic differences in symptoms of post-traumatic stress after the Exxon Valdez oil spill

Previous studies have reported ethnic differences in the prevalence of post-traumatic stress disorder (PTSD), but the reasons for these differences remain unclear.

Ethnic differences in the prevalence of PTSD may reflect ethnic differences in (1) exposure to traumatic events; (2) appraisal of such event as traumatic; and (3) culturally-determined responses to standardized diagnostic instruments, reflecting differences in cultural meanings associated with physical symptoms and idioms of distress.

Ethnic differences in risk factors and factor structures of PTSD symptoms were examined in 188 Alaskan Natives and 371 Euro-Americans exposed to the Exxon-Valdez oil spill in 1989.

High levels of social disruption were associated with PTSD one year after the oil spill in both ethnic groups. However, low family support, participation in spill clean-up activities, and a decline in subsistence activities were significantly associated with PTSD in Alaskan Natives, but not in Euro-Americans. Factor analysis of the Diagnostic Interview Schedule PTSD subscale revealed five factors for both ethnic groups. However, the items comprising these factors were dissimilar.

These results suggest that social disruption is sufficiently traumatic to be associated with symptoms of post-traumatic stress, but that a diagnosis of PTSD must take into consideration local interpretations of these symptoms.