About 10 percent of mothers experienced chronic, persistent depressive symptoms two years after Hurricane Katrina slammed into the Gulf Coast, killing more than 1,800 people, displacing hundreds of thousands and causing widespread damage estimated at more than $100 billion, according to a Georgia State University study. While most people don't develop persistent depression after a major disaster like that, a small but significant number will, according to a study led by Dr. Betty S. Lai, assistant professor of epidemiology and biostatistics at the School of Public Health at Georgia State.

The study, titled "Hurricane Katrina: Maternal Depression Trajectories and Child Outcomes," was published recently in Current Psychology. It tracked 283 mothers and their children who were living in southern Louisiana during Hurricane Katrina. Researchers examined their depression levels during the two years following the storm. 

"Overall, our findings indicate that the majority of mothers did not report elevated depressive symptom trajectories postdisaster," the report stated. However, 10 percent of the mothers reported "chronic, persistent depressive symptoms more than two years postdisaster."

Because maternal depression has been linked to negative parenting practices and increased behavioral problems in children, "understanding maternal depression following a disaster is necessary for developing interventions for improving maternal adjustment," the report said. 

The study focused specifically on low-income women, the majority of whom are single parents. In their report, the researchers noted that mothers, in general, may report higher levels of depression after large-scale disasters because they often place the needs of their children above their own. Impoverished mothers face an even greater risk of developing depression in those circumstances because they may have scant support resources.

The study also examined how maternal depression affected children, focusing on symptoms such as posttraumatic stress, depression and anxiety. Surprisingly, maternal depression trajectories were not associated with differences in children's distress symptoms," the report stated. 

Researchers noted that studies examining fathers' distress symptoms are needed to better understand the family dynamic after disasters.