Frequent nightmares or bouts of night terrors in children may be an early warning sign of psychotic disorders, according to a recent study, reported by the Examiner.

Researchers from the University of Warwick in the United Kingdom found that children who regularly suffer from nightmares before the age of 12 were three and a half times more likely to develop delusions, hallucinations and other psychotic episodes. Those who suffered from night terrors had double the risk of such problems, the Examiner reported.

Those who have experienced nightmares will be familiar with the sensation of waking suddenly with a sense of fear, worry and possible palpitations. Night terrors, a sleep disorder, are often signified by a loud scream and the individual sitting upright in a panicked state, though unaware of any of the involuntary action. The thrashing of limbs and rapid body movements are witnessed in more extreme cases. Children wake up in the morning unaware of their activity throughout the night.

"We certainly don't want to worry parents with this news; three in every four children experience nightmares at this young age," researcher Dieter Wolke 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."

For the study, researchers examined data from the Avon Longitudinal Study of Parents and Children (ALSPAC), based in England. The group included more than 6,700 children and involved multiple assessments.

They found that those who only reported one period of recurrent nightmares saw a 16 percent increase, whereas those who reported three or more sustained periods of nightmares throughout the study saw a 56 percent increase in risk.

The study participants were examined six times between the ages of two and nine. The likelihood of experiencing psychotic experiences in adolescence increased with the incidence of nightmares.

Lucie Russell, Director of Campaigns at YoungMinds, an organization that focuses on child and adolescent mental health, said the study is important because it helps "promote early identification of signs of mental illness," which is vital to help the thousands of children that suffer.

"Early intervention is crucial to help avoid children suffering entrenched mental illness when they reach adulthood," Russell said.