One in four preschool kids, who survived the 2011 quake and tsunami, need psychiatric care.

According to latest study by researchers at Tohoku University School of Medicine and colleagues, about 25.9 percent of children aged between 3 and 5 suffer from nausea, headache and vertigo. Many children in the study also displayed symptoms of withdrawal and aggression, The Japan Times reported.

Researchers have said that the children are most likely to suffer from serious health conditions in the future.

Their study was based on responses of 178 children from Iwate, Miyagi and Fukushima, AFP reported. Researchers used standard child behavior checklist for the study. The survey was conducted between September 2012 and June 2013.

Researchers found that the number of children needing urgent psychiatric care was roughly three times higher than those living in regions of Japan that weren't affected by the disaster.

 "I was surprised at the percentage of children who need medical care. I didn't expect it would be this high," Shigeo Kure of Tohoku University School of Medicine told AFP.

"It is known that children need (psychiatric) care right after an earthquake disaster, but this study was done more than a year and half after the fact, so that concerns me," said Makiko Okuyama of the National Center for Child Health and Development, who participated in the study, according to The Japan Times.

magnitude-9 earthquake shook North-eastern Japan March 11, 2011. The mega earthquake and tsunami were followed by a level 7 nuclear meltdown. About 18,000 people died in the disaster.