It's a nightmare for the exhausted new mother--a constantly squalling infant. And if the baby can't calm down after a few months, it's a bad sign: A new study suggests that prolonged crying may be a sign of future behavioral problems.
When newborns cry inexplicably for hours every day, it's called colic. But colic rarely persists beyond 3 months and is not associated with later ill effects. More persistent crying, however, may be a symptom of flawed neurological development, according to a paper in the November Archives of Disease in Childhood.
Researchers at the National Institute of Child Health and Human Development in Bethesda, Maryland, analyzed data from a study of normal full-term infants born in Norway and Sweden in the late 1980s. The babies were evaluated periodically in the first 13 months of life, and about 5 years later, 327 children--or 80% of the original sample--were given tests probing their health, IQs, motor abilities, and personalities. Of these, 63 were colicky, and 15 continued to be prolonged criers. The colicky infants showed no decrements on the later tests, but the criers' average IQ was 9 points below that of the other children. The criers also had worse hand-eye coordination and were more likely to be hyperactive or present discipline problems.
Although the sample is small, the authors say they were able to rule out confounding factors including health problems, maternal IQ, and socioeconomic status. "It is likely that the prolonged crying behavior is indeed a reliable predictor" of impaired cognitive development, says lead author Malla Rao of the National Institute of Allergy and Infectious Diseases. The crying may stem from "irritability caused by subtle underlying neurological problems," the authors speculate.
Dieter Wolke, a psychologist at The Jacobs Foundation in Zurich, Switzerland, says the study is congruent with his research showing that criers are more likely to be hyperactive. The research has "important implications," he says, because problems are usually not diagnosed until children enter school.