A little over half of the children in the U. S. who have mental problems, including attention-deficit hyperactivity disorder, get professional help, federal health officials report.

However, “you could look at it the other way that half don't," said Kathleen Merikangas, a senior investigator at the U. S. National Institute of Mental Health and lead researcher of a study published online December 14 in Pediatrics.

Depression and anxiety often go undiagnosed and untreated, the study found.

The data came from youths aged 8 to 15 whose families participated in the National Health and Nutrition Examination Survey from 2001 to 2004. The youths were interviewed, and parents and caregivers also provided details about their children's mental health.

The researchers looked at six mental problems; generalized anxiety disorder, panic disorder, eating disorders, depression, ADHD and conduct disorder. They found that 8.6 percent had ADHD, including more boys than girls, 3.7 percent had depression, more common among girls, 2.1 percent had a conduct disorder, 0.7 percent had an anxiety or panic disorder and 0.1 percent had an eating disorder such as anorexia or bulimia.

Merikangas said that anxiety and depression are the most neglected problems.

And the earlier mental health problems are identified the chance of resolving them are better, she said.

Dr Jon Shaw, a professor and director of child and adolescent psychiatry at the University of Miami Miller School of Medicine, agreed that anxiety and depression in children often go unrecognized.

Depression and anxiety in children can lead to mood disorders in teenagers, he said.