The numbers echo other estimates suggesting as many as 1 million U.S. children are bipolar, but it remains a controversial diagnosis in children. That’s partly because their symptoms often differ from adults’, and because most powerful antipsychotic drugs used to treat bipolar disorder were approved for adults and have not been well-studied in children. Some doctors believe bipolar disorder doesn’t occur in children, and until last month there was only one drug approved to treat the illness in kids.

The study’s lead author, Dr. Mark Olfson of Columbia University and the New York State Psychiatric Institute, said the results likely reflect over-diagnosis now or under-diagnosis in the past, rather than a true increase. Olfson has received speaking fees from Janssen LP, which makes one of the pediatric bipolar drugs, and has consulted for other makers of psychiatric drugs. More public awareness about mental illness, spurred partly by heavy marketing of psychiatric drugs, could have contributed to the surge. And early in the study, a leading manual of psychiatric illnesses expanded criteria for diagnosing bipolar disorder, Olfson noted.

Symptoms include extreme mood swings and disruptive behavior. In children, extreme irritability is sometimes the main symptom.

Dr. David Fassler, a University of Vermont psychiatry professor, said research suggests that close to half of children thought to be bipolar may be misdiagnosed. He said parents should get a second opinion if they have concerns about a diagnosis or proposed treatment. “Bipolar disorder is not always easy to recognize in children and adolescents. There’s considerable overlap with other conditions, including ADHD, conduct disorder, anxiety disorders and depression,” said Fassler, who was not involved in Olfson’s study.

The study appears in the September issue of Archives of General Psychiatry. It follows a report showing a big increase in U.S. children hospitalized with bipolar disorder, from 1.3 per 10,000 in 1996 to 7.3 per 10,000 in 2004, published in June in the journal Biological Psychiatry. Olfson and colleagues analyzed annual surveys of outpatient visits from the National Center for Health Statistics. Adult visits for bipolar disorder also increased during the study but not as markedly.

___

On the Net:

Archives: http://www.archgenpsychiatry.com

National Institute of Mental Health: http://www.nimh.nih.gov

Children & Adolescent Bipolar Foundation: http://www.bpkids.org

Copyright © 2007 The Associated Press.