NEW YORK (Reuters Health) - Results of a Swedish population-wide study hint that children born prematurely have some risk of developing anxiety, depression or other psychiatric disorder in adolescence and young adulthood.

Children born “preterm” should therefore be watched more closely for these disorders, the investigators suggest.

Among 545,628 Swedish residents born in the 1970s and followed up until 23 to 29 years of age, Dr. Karolina Lindstrom from Sachs Children’s Hospital, Stockholm, and colleagues observed a stepwise increase in psychiatric hospital admissions with an increasing degree of preterm birth.

A normal pregnancy lasts 40 weeks. Lindstrom’s team found that 3.5 percent of subjects born moderately preterm at 29 to 32 weeks of pregnancy and 5.2 percent born very preterm at 24 to 28 weeks of pregnancy had been hospitalized because of a psychiatric disorder.

They report their finding in the January 2009 issue of Pediatrics.

Compared with those born at 40 weeks, the risk for psychiatric disorders was 68 percent higher in the very preterm group (birth at 24 to 32 weeks), 21 percent higher in the moderately preterm group

(birth at 33 to 36 weeks), and only 8 percent higher in the early term group (birth at 37 to 38 weeks).

Alcohol- and drug-related hospital admissions were not more common in adolescent and young adult ex-preterm infants. “These results,” Lindstrom and colleagues note, “are in line with previous studies reporting that addictive behavior is not an important problem in this group.”

The investigators conclude, based on their findings, that adolescent and young adults who were born prematurely are a group “in need of more attention in research and secondary prevention” of psychiatric morbidity.

SOURCE: Pediatrics, January 2009.