A new study finds that children who lived in emergency trailer parks or hotels for long periods after Hurricane Katrina are far more likely to have serious emotional problems.

In a report being released Monday, researcher Irwin Redlener says at least 20,000 of those children still have serious emotional disorders or behavior problems, or don’t have a permanent home.

He says they’re 4.5 times more likely to have serious emotional disorders than children from similar families in a national study in 2004.

Psychologist Joy Osofsky has worked with children in schools in three parishes hit hard by the storm. She says it’s important to note that children in general are much more resilient than those from the extremely poor families Redlener is studying.