Stress and trauma are extracting their bitter toll from Queensland's Lockyer Valley residents, with many reporting flashbacks, anxiety and difficulty sleeping — symptoms that can foreshadow post-traumatic stress disorder.

Some are turning to alcohol to soothe the pain, but for others the stress already appears too great, with suggestions that perhaps one in five of Grantham’s evacuated residents may never re-occupy their homes. Leaving a community meeting yesterday, Grantham resident Paul Lindenmayer, 27, was still unable to come to terms with what had happened.

"Put it this way: I can’t eat and I can’t sleep," he said.

Mr Lindenmayer’s home — his first — was virtually destroyed.

"Who’s going to want to live here, even if the house is all right?" he said. "There’s a lot of talk about people who don’t want to come back."

Asked how many people might never return, Mr Lindenmayer replied: "Maybe 20 per cent."

At his flood-ravaged home in Murphys Creek, bill Scothey looked stunned. when the water scoured his property last week, he, like so many of his friends and neighbours, barely escaped with his life.

"I can’t believe I’m still here," he said. "I was all right until yesterday, then it all welled up."

Of the several dozen residents interviewed by the Australian in recent days, most reported sleeping problems, flashbacks, severe anxiety or a combination of all three and more.

Many said they had trouble remembering the details of their struggle to save families, property and livelihoods from the rising flood. Experts say these are classic symptoms of stress and trauma resulting from natural disasters that, if not managed properly, could lead to long-term mental health problems such as post-traumatic stress disorder.

Sadly, those problems are only made worse by storm clouds that threaten more wet weather.

In Grantham yesterday, police drove down main streets announcing by loud-hailer a severe thunderstorm warning.

At the pub in nearby Murphys Creek, Troy Johns, who survived by clinging to his verandah while his family huddled on his house roof, said he was keeping busy to stop his mind returning to the disaster.

"I come to work here every day and it’s all right because I don’t think about it, but in the afternoons, when it starts to slow down, I start thinking about it again and then I drink vodka," he said.

Mr Johns said he had been drinking vodka just to get to sleep.

Mayor of the Lockyer Valley Shire Council, Steve Jones, said stress was not just affecting residents, but rescue crews, volunteers and others who had offered their help.

"It’s not going to be hundreds, it’ll be thousands that are affected," he said. "the amount of grief these people have is immense."