Newswise — Almost half of pre-hurricane residents of New Orleans and one-fourth of those living in other affected areas had evidence of an anxiety or mood disorder five to seven months following Hurricane Katrina, according to a report in the December issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

"Hurricane Katrina was the worst natural disaster in the United States in the past 75 years, creating a disaster region as large as Great Britain, killing more than 1,000 people, uprooting 500,000 others and causing more than $100 billion in damage," the authors write as background information in the article. "This vast devastation would lead us to expect a high prevalence of mental illness among people who lived through Katrina."

Sandro Galea, M.D., Dr. P.H., of the University of Michigan School of Public Health, Ann Arbor, and colleagues surveyed 1,043 residents who had been living in affected areas of Louisiana, Alabama and Mississippi before Hurricane Katrina. The telephone survey was conducted between Jan. 19 and March 31, 2006, five to seven months after the storm. Participants were asked about stressors related to the hurricane and screened for symptoms of mood and anxiety disorders—which include depression, panic disorders and post-traumatic stress disorder (PTSD)—within 30 days of the interview.

A total of 31.2 percent of the participants had an anxiety-mood disorder, including 49.1 percent of the New Orleans metropolitan area residents and 26.4 percent of the other participants. Among all participants, 16.3 percent had PTSD; this included 30.3 percent of New Orleans residents and 12.5 percent of the others. Individuals who were younger than age 60, female, did not graduate college, had a low family income or were unmarried or unemployed before the hurricane were more likely to have anxiety-mood disorders, and those who were Hispanic or other minorities excluding blacks had lower rates of these conditions.

"The vast majority of respondents both in the New Orleans metro (91.9 percent) and in the remainder of the sample (81.7 percent) reported experiencing at least one of the 10 categories of hurricane-related stressors," including the death of a loved one, robbery, injury or property loss, the authors write. Among New Orleans residents, the extent of exposure to these stressors was more strongly related to anxiety-mood disorders than among residents of other areas. While New Orleans residents were most likely to develop anxiety-mood disorders following physical illness or injury and physical adversity, the rest of the participants were more likely to develop such a disorder following property loss.

The rate of anxiety and mood disorders in New Orleans residents was higher than that typically found in studies of mental illness following natural disasters in the United States, while the rate among the other respondents was roughly equivalent, the authors note. In addition, they conclude, "evidence that avoidable stressors associated with the slow government response to Hurricane Katrina (e.g., physical adversity) had important implications for the mental health of people who lived through Katrina argues strongly for the importance of efficient provision of practical and logistical assistance in future disasters, not only on humanitarian grounds, but also as a way to minimize the adverse mental health effects of disasters." (Arch Gen Psychiatry. 2007;64(12):1427-1434. Available pre-embargo to the media at www.jamamedia.org.)

Editor's Note: The Hurricane Katrina Community Advisory Group (CAG) is supported by a grant from the National Institute of Mental Health with supplemental support from the Federal Emergency Management Agency and the Assistant Secretary for Planning and Evaluation, Department of Health and Human Services. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.