This study estimated the impact of Hurricane Katrina on mental illness & suicidality by comparing results of a post-Katrina survey with those of an earlier survey. The post-Katrina survey interviewed a sample of 1043 adults who lived in the same area before the hurricane. The same questions were asked about mental illness & suicidality as well as questions on personal growth that resulted from the trauma. Respondents to the post-Katrina survey had a significantly higher estimated prevalence of serious mental illness. Among respondents estimated to have mental illness, though, the prevalence of suicide ideation & plans was significantly lower in the post-Katrina survey; this finding was strongly related to 2 dimensions of personal growth after the trauma. (49 refs.)