It’s normal for a young child to have tantrums and be otherwise disruptive, but researchers have found that if such behavior is prolonged or especially intense, the child may have conduct disorder, a childhood psychiatric problem that could be a harbinger of antisocial behavior.

Researchers at Washington University School of Medicine in St. Louis found that certain symptoms of conduct disorder indicate problems are likely to continue as kids reach school age. They recommend that children who exhibit these symptoms — among them, high-intensity defiant behavior, aggression and destruction of property — be referred to mental health professionals for evaluation and possible intervention.

Their findings are published Jan. 15 in The Journal of Pediatrics.

“Previously, we did not understand the empirical differences between normal disruptive behaviors in preschoolers – like temper tantrums, for example — and behaviors that signal problems,” said senior investigator Joan L. Luby, MD, professor of child psychiatry. “If you went to your pediatrician and said, ‘My 3-year-old is having tantrums,’ the pediatrician wouldn’t tell you to see a psychiatrist.”

Although there was overlap between healthy young children and their peers who had conduct disorder, the researchers found that those who exhibited high-intensity defiant behavior, aggression toward people or animals, high-intensity destruction of property, peer problems and deceitfulness, including stealing, were likely to have conduct disorder. Having those symptoms also made it more likely they would carry the disorder into elementary school.

“We characterize a symptom as high-intensity when it’s really ‘high-pitched’ — so just how severe the anger is,” Luby said. “Other factors that would qualify a symptom as high-intensity would hinge on how frequently the behavior occurs and the context in which it occurs. A high-intensity symptom is one that is very acute or severe, occurs over a long duration of time and happens in a number of different contexts.”

“Children who had high-intensity symptoms as preschoolers were likely to have conduct disorder,” said first author Ji Su Hong, MD, who now works as a mental health provider for children treated at Grace Hill Health Centers in St. Louis. “And those symptoms also tended to predict conduct disorder when they reached school age.”

Grace Hill operates neighborhood-based health centers and a community health program in the St. Louis region.

Although healthy preschoolers also engage in disruptive behaviors — including losing their tempers, throwing toys and being untruthful — about one in 20 preschoolers has conduct disorder.

“That’s about one child per preschool class,” Hong said. “And conduct disorder is a serious problem when it affects a child under 10 because early-onset problems are more likely to persist as the child grows up.”

Kids with conduct disorder often have other disadvantages, too. Many children with school-age conduct disorder in the study were from homes with low incomes, with almost half from families with incomes of $20,000 a year or less. Further, about half had a history of abuse or neglect; 43 percent came from intact families, meaning more than half were either from single-parent homes or didn’t live with either parent; and more than half had been diagnosed with preschool depression.

Hong and Luby believe that the best chance young children have to avoid recurring problems is early diagnosis and treatment.

“In young children, violent and destructive behavior that’s deliberate really seems to be a key warning sign,” Luby said.