Nightmares can be traumatic for children, but new research suggests kids who have lots of frightening dreams may be at an increased risk for psychotic experiences come adolescence.
"We certainly don't want to worry parents with this news," Professor Dieter Wolke, a psychologist at the University of Warwick in the U.K., said in a statement.
"However, nightmares over a prolonged period or bouts of night terrors that persist into adolescence can be an early indicator of something more significant in later life," he added.
Nightmares are common in childhood during the REM (rapid eye movement) part of the sleep cycle, what's considered the deepest part of sleep. They usually contain vivid and disturbing content, and you often immediately wake from and remember the dream, the National Sleep Foundation notes. Wolke said about three out of four children under the age of 12 experience them.
They're not as extreme as night terrors, which often occur during non-REM cycles of sleep in the first half of the night. A person usually wakes up with a loud scream, sitting upright in a panicked state. The child typically has no memory or a vague recollection of the terrifying events.
Researchers assessed a study pool of nearly 6,800 kids who were enrolled in a long study involving children born during the 1990s. They were examined six times between the ages of 2 and 9.
The more nightmares, the more likelihood a child experienced psychotic experiences. Those who reported one bout of recurrent nightmares saw a 16 percent rise in rick, but those with more sustained periods of nightmares saw a 56 percent increase. Children under 9 who had persistent nightmares were 1.5 times more likely to develop psychotic experiences including hallucinations, delusions and interrupted thoughts.
Night terrors doubled the risk for these problems.
Last October, a study found irregular sleep times in children may increase risk for behavioral problems.
The researchers said worried parents should try to help their kids maintain proper sleep habits. That includes creating a relaxing sleep environment that's not too hot or cold or bright, avoiding naps during the day, skipping caffeine and sugary drinks and avoiding large meals close to bedtime.
Also, leave the television, video games and computers out of the bedroom.
"This is a very important study because anything that we can do to promote early identification of signs of mental illness is vital to help the thousands of children that suffer," Lucie Russell, director of campaigns at the British mental health charity YoungMinds, said in a press release.
The study was published Feb. 27 in SLEEP.