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Mental Disorders Persist Among Hurricane Katrina Survivors

Science Update

More residents affected by Hurricane Katrina are enduring mental disorders than was initially determined a few months after the storm, according to a study published online January 8, 2008, in the journal Molecular Psychiatry.  The trend runs counter to the typical pattern of recovery after a natural disaster, in which the prevalence of mental disorders among the survivors gradually decreases and fades out after about two years.

Ronald Kessler, PhD, of Harvard University and colleagues compared survey data from 815 respondents who were polled about their mental health five to eight months after the disaster, and again one year after that. Rather than declining, the occurrence of certain mental disorders had increased. For example, the prevalence of serious mental illnesses increased from 11 percent to 14 percent. The prevalence of suicidal thoughts increased from 2.8 percent to 6.4 percent, and the prevalence of people with actual suicide plans increased from 1 percent to 2.5 percent.

Post-traumatic stress disorder (PTSD) increased as well, but only among those respondents living outside of the New Orleans metro area—up from 15 percent in the original survey to 21 percent in the follow-up survey. The prevalence of PTSD in the New Orleans metro area increased slightly but not significantly (from 24 percent to 26 percent). Mood and anxiety disorders followed a similar upward pattern, but the change was not statistically significant either (from 30.7 percent to 34 percent).

However, hurricane-related stress decreased for people in the New Orleans metro area (from 98 percent to 78.3 percent) and even more so for respondents living outside of the New Orleans area (from 90 percent to 51.7 percent). The discrepancy between decreasing stress levels and increasing PTSD among the respondents living outside of the New Orleans metro area suggests that other unknown stresses or vulnerabilities are at work.  Additional research will be needed to identify these stresses and reconcile this apparent contradiction, according to the researchers.

The study results underscore the negative impact of the slow pace of recovery on Katrina-affected communities and survivors. The high rate of hurricane-related stress and the increase in some forms of mental illness nearly two years after the event suggest a continued need for practical and health-related assistance for the survivors. And because more people outside of the New Orleans area appear to be battling PTSD, they may need special attention.


Kessler RC, Galea S, Gruber MJ, Sampson NA, Ursano RJ, Wessely S. Trends in mental illness and suicidality after Hurricane Katrina . Molecular Psychiatry. online ahead of print Jan 8, 2008.