Bipoloar Disorder: Predicting At-Risk Children Earlier

BY KRISTA CONGER

Eight-year-old Takeshi Yamaguchi (front) was diagnosed with attention-deficit / hyperactivity disorder at age 3 and bipolar disorder at age 6. His 10-year-old sister, Misaye, also has a mood disorder. Both are patients of child psychiatrist Kiki Chang, M.D., who is conducting a study to identify better medications for children with bipolar disorder and related illnesses.

WINTER 2003 - The devastating mood swings that are the hallmark of pediatric bipolar disorder are all too familiar to some parents, who may themselves struggle with the disease. Children of bipolar parents are up to four times as likely as their peers to suffer from some type of mood disorder. They are also likely to develop the condition at a younger age and in a more severe form than their parents.

Although the reasons for this disparity remain unclear, it's known that early diagnosis makes for much more effective treatment. Some researchers believe that treatment before symptoms begin might even stop the disease in its tracks. But how to identify which children in an at-risk family should receive treatment?

Child psychiatrist Kiki Chang, M.D., sees many children with bipolar disorder as patients. Recently he has begun to recruit them to participate in a study comparing the DNA of affected and unaffected parents and children. Chang hopes he may be able to identify particular genetic markers that can be used to pinpoint which at-risk children will go on to develop the disease before symptoms arise.

Chang also is conducting studies to identify better medications for bipolar children, who are often first diagnosed with attention-deficit/hyperactivity disorder or other mood disorders such as depression. The antidepressants and stimulants that are usually an effective treatment for these problems can drive an at-risk child into a manic phase, making the situation, and the symptoms, much worse. Chang wondered whether a drug called divalproex, or Depakote, that works well to suppress mania in adults could help kids who did not yet have full-blown bipolar disorder.

His hunch paid off: About 80 percent of the children in a recent study showed marked improvement in their mood or behavior.

"We analyzed the brain function of these children with early symptoms of bipolar disorder and found specific changes in areas of mood and attention regulation," says Chang. "It seems that the medication decreased activity in regions that we feel are over-activated in bipolar children, kind of cooling off those parts of the brain. The most interesting part of these studies, however, will be determining whether the drug can delay or prevent the development of bipolar disorder in these at-risk kids who don't yet have the full disorder."

Since mood disorders have a genetic component, the entire Yamaguchi family has participated in Chang's study to look for genetic markers that might indicate whether a child is likely to develop bipolar disorder. Melody Yamaguchi (second from right) has the illness, as does her father.

Chang's clinical success with children in the study also has pinpointed another possible area of research: how best to suppress the symptoms of ADHD that continue to plague some of these children even after their bipolar disorder is under control.

"It's a little too early to say that every child with a family history of bipolar disorder should be put on medications such as divalproex," he says. "We're finally beginning to understand the global spectrum of these disorders -- how the brain develops in children and how mood is regulated.We're hoping that all of these studies will lead to earlier diagnosis and better treatment of bipolar and other mood disorders, as well as ADHD."