Big coffee drinkers are taking a latte break from reality, with half of them likely to hallucinate or hear things, the Herald Sun reported Wednesday.

If the break is supposed to be a stress-buster -- as it often is -- that makes things worse. And if a cigarette is involved, you're playing with fire.

Research at Victorian university La Trobe found that stressed coffee lovers are three times more likely to see or hear imaginary things than everyone else.

In tests, they heard Bing Crosby singing "White Christmas" -- or at least thought they did.
Professor Simon Crowe tested 92 people with varied caffeine-intake and stress levels. Subjects thought they were doing hearing tests and were initially subjected to Bing.

Then they were played three minutes of static hiss and asked to press a buzzer if they heard snippets of White Christmas in there -- which there weren't.

On average, low-caffeine subjects heard it once. But stressed coffee guzzlers buzzed three times.

"If you are stressed and have a high level of caffeine, you are more likely to notice things that aren't there, see things that aren't there," Crowe said.

Click here to read more on this story from the Sun.