Misdiagnosis Widespread, Experts Claim
By Rosemary Frei, MSc
A recently published study documents a more than 3-fold increase between 1996 and 2004 in bipolar diagnosis rates among children discharged from the hospital, along with a doubling of the rate among adolescents (Biol Psychiatry. 2007;62:107-114). The investigators believe that the disorder is being overdiagnosed in the pediatric population by many physicians.
"Growth in the rate of bipolar disorder-diagnosed discharges might reflect a progressive rebranding of the same clinical phenomena for which hospitalized children previously received different diagnoses," write Joseph Blader, PhD, and Gabrielle Carlson, MD.
Using data from the National Hospital Discharge Survey, Drs Blader and Carlson found that the rate of bipolar diagnoses jumped from 10.0% to 34.1% for all pediatric psychiatric discharges during the study period, and it rose from 10.2% to 25.9% in adolescents. They calculated that the adjusted odds ratio for a hospital discharge diagnosis of bipolar disorder in children increased by 25% annually.
Although there were twice as many discharges of adolescents with a depressive disorder as with bipolar disorder in 1996, bipolar disorder discharges had caught up with depression discharges by 2004. Furthermore, the distribution of bipolar subtypes in adults remained the same between 1996 and 2004. The rate of psychotic features in bipolar children jumped from 7% before 2001 to >15% in subsequent years.
Drs Blader and Carlson, both of Stony Brook State University of New York School of Medicine, observe that the results underline the gray areas in the diagnosis of bipolar disorder in children.
"Nearly everyone knows that the symptoms and course of bipolar in adults are different from the problems we see in children," said Dr Blader.
"Is there any point in saying their clinical picture is some special form of bipolar disorder that children get? It implies that we know more about the illness than we do, or that if we treat these kids as if they have bipolar disorder they'll have better outcomes. And there's just no evidence for that now."