When does bipolar disorder begin? That question confounds clinicians, worries parents, and is leading researchers such as Kiki D. Chang, MD, to look for answers in families with this highly heritable disorder.
“Parents with bipolar disorder know what’s happening if their children have early symptoms,” Dr. Chang says. “They tell me, ‘I don’t want my child to go through what I went through, and he’s having the same symptoms I did.’”
Dr. Chang believes early psychotherapy and medication might prevent prodromal bipolar disorder from fully developing. His team at Stanford University is among those seeking genetic and brain imaging biomarkers to make a pediatric bipolar diagnosis more reliable. Lack of age-specific criteria may be causing overdiagnosis, as suggested by a 40-fold increase in 10 years in the number of children and adolescents being treated for bipolar disorder.1
In this interview by Robert A. Kowatch, MD, PhD, Dr. Chang describes a child with probable early signs of bipolar disorder and discusses why early intervention is both complicated and promising.
Children at risk for bipolarity
DR. KOWATCH: You’re studying children considered at high risk for developing bipolar disorder; why are these studies important?
DR. CHANG: High-risk children represent a chance to understand risk factors for developing bipolar disorder and what the early symptoms are. By “high risk,” we mean children and adolescents who possess a genetic predisposition toward bipolar disorder.
Bipolar disorder develops over time; a boy such as “Brian” (Box 1) likely would have gone 3 to 5 years on the stimulant—not doing well—until he had a manic episode at age 14 or 15. The full mood episode usually does not develop until later, with the right—or you could say wrong— combination of environment and stressors acting on a genetic predisposition.
DR. KOWATCH: Do the parents of the children you’re studying have bipolar disorder?
DR. CHANG: Yes; we’re studying what we call “bipolar offspring”—children with biological parents with bipolar disorder (Box 2).2-4 One also could look at siblings; having a brother or sister with bipolar disorder increases risk as well. If you search back in these families, usually you’ll find many relatives with bipolar disorder who reflect the child’s genetic predisposition.
Case report: 10-year-old is ‘just like I was,’ says bipolar mom
Box 2Mrs. M, age 35, had early-onset depression but was not diagnosed with bipolar disorder until age 22. She requests a consultation for her 10-year-old son, Brian, whom she suspects also may have bipolar disorder. “I know there’s something going on; he’s just like I was, but no one would listen to me,” she says.
The boy’s pediatrician prescribed methylphenidate for “a little inattention” but felt that Brian was doing okay in school and had some friends. The stimulant might be helping, says Mrs. M, but she is not sure.
You talk to Brian and learn he has some anxiety. He sometimes gets very excited and runs around, and sometimes he does not sleep well. If you consider all the symptoms, this child has anxiety, attention-deficit/hyperactivity disorder, short depressive periods that affect his functioning, and a parent with bipolar disorder.
You ask further, and Brian tells you about hearing conversations and voices of old friends, his parents, and unknown people in his head, usually neutral, and not commanding or commentating. No one has asked him about parapsychotic phenomena, and he’s never reported this to anyone.
‘Bipolar offspring’: High risk for bipolar disorder
In adults, the incidence of bipolar types I and II is approximately 4%.1 Because two-thirds of adults with bipolar disorder have onset during childhood or adolescence, the incidence of pediatric bipolar disorder may be 1% to 2%. It could be as high as 3% if you include children with prodromes or early forms of the disorder.
The risk of a child developing a bipolar disorder is probably 15% to 20% when 1 biological parent—or sibling—has a bipolar disorder.2 If both parents have bipolar disorder, some older studies suggest that the child’s risk of developing at least a mood disorder would be up to 75%,3 and depression in a child might develop into a bipolar disorder.
Therefore, the risk of bipolar disorder developing in a child whose parents both have bipolar disorder may be >50% and could approach 75%.
‘Kindling’ in bipolar disorder
DR. KOWATCH: What have you seen in children whose parents have bipolar disorder?
DR. CHANG: We’ve tracked more than 200 bipolar offspring for up to 10 years. In some families we’ve seen the natural progression toward full mania and bipolar disorder.