Researchers at Drexel University looked at data on more than 1.1 million children born from 1984 to 1994 in Sweden and linked their school performance at the end of the northern European nation's compulsory education at about age 16 with parents' depression diagnoses from inpatient and outpatient records.

　　They found children whose mothers had been diagnosed with depression are likely to achieve grades that are 4.5 percentage points lower than peers whose mothers had not been diagnosed with depression.

　　Parental depression may hurt children school performance: <a href=http://www.hxen.com target=_blank class=infotextkey>study</a>

　　For children whose fathers were diagnosed with depression, the difference is a negative four percentage points, according to the study published in the U.S. journal JAMA Psychiatry.

　　Put into other terms, when compared with a student who achieved a 90 percent, a student whose mother or father had been diagnosed with depression would be more likely to achieve a score in the 85 to 86 percent range.

　　The study also showed that maternal depression appeared to have a larger negative effect on girls than boys. Girls scored 5.1 percentage points lower than their peers on final grades at 16 years old, while boys only scored 3.4 percentage points lower, it said.

　　"Our study -- as well as many others -- supports that both maternal and paternal depression may independently and negatively influence child development," senior author Brian Lee, associate professor at Drexel University's Dornsife School of Public Health, said in a statement.

　　"There are many notable sex differences in depression, but, rather than comparing maternal versus paternal depression, we should recognize that parental depression can have adverse consequences not just for the parents but also for their children," Lee said.

　　In an accompanying editorial, Myrna Weissman of Columbia University said the findings highlighted the importance of treating parents who suffered from depression.

　　"The study ... concludes that 'diagnoses of parental depression may have a far-reaching effect on child development.' We extend that conclusion to state that effective treatment of the diagnosed parents may also have far-reaching effects," Weissman wrote.

　　"Access to treatments that are vigorous, substantiated and evidence-based is a public health opportunity for improving the lives of both depressed parents and their children."