About 44 percent of individuals who had bipolar disorder as children continue to have manic episodes as young adults, according to a report in the October issue of Archives of General Psychiatry, one of the JAMA/Archives journals. This rate, along with the severity of the disease at young ages, strongly suggest that bipolar disorder can be continuous from childhood to adulthood, the authors note.

Recent data has demonstrated an enormous increase in the diagnosis of pediatric bipolar disorder according to background information in the article. However, skepticism continues to exist regarding the existence of the condition in children.
Barbara Geller, M.D., and colleagues at Washington University in St. Louis studied 115 children (average age 11.1 years) diagnosed with bipolar disorder from 1995 to 1998. At the beginning of the study and again during nine follow-up visits conducted over eight years, the children and their parents were interviewed separately about their symptoms, diagnoses, daily cycles of mania and depression and interactions with others.

A total of 108 (93.9 percent) of the children completed the study (average age at follow-up, 18.1 years). During the eight-year follow-up, they spent 60.2 percent of weeks with any mood episodes and 39.6 percent of weeks with episodes of mania. Although 87.8 percent recovered from mania, 73.3 percent relapsed. The researchers also examined the characteristics of children's second and third episodes of mania and found that like the first episodes, they were characterized by psychosis, daily cycling between mania and depression and a long duration (55.2 weeks for the second and 40 weeks for the third episode).

At the end of the follow-up period, 54 patients were age 18 or older. Of those, 44.4 percent continued to have manic episodes and 35.2 percent had substance use disorders, a rate similar to those diagnosed with bipolar disorder as adults.

"In grown-up subjects with child bipolar disorder I, the 44.4 percent frequency of manic episodes was 13 to 44 times higher than population prevalences, strongly supporting continuity between child and adult bipolar disorder I," the authors write. "Subjects with child bipolar disorder I who were grown up at the eight-year follow-up constituted approximately half the sample. However, even if all subjects younger than 18 years at the eight-year follow-up never had episodes of bipolar disorder I as adults, the overall significance of the findings would be similar, because the rate would still be six to 22 times higher than population prevalences."

"In conclusion, mounting data support the existence of child bipolar disorder I, and the severity and chronicity of this disorder argue strongly for large efforts toward understanding the neurobiology and for developing prevention and intervention strategies," they write.

In an accompanying editorial, Ellen Leibenluft, M.D. of the National Institute of Mental Health, Bethesda, MD writes, "Extending previous seminal work on pediatric bipolar disorder, Geller et al present the first longitudinal study following up a large sample of youth diagnosed with pediatric bipolar disorder into adulthood."

"Just as the children in this important study have matured over the last decade, so has research on pediatric bipolar disorder," Dr. Leibenluft writes. More articles on the condition were published in January 2008 than in the decade between 1986 and 1996.

"This upsurge both results from and contributes to a growing awareness that serious mental illnesses do not emerge de novo when individuals reach adulthood, but rather reflect early developmental processes. This awareness has profound implications for future research, highlighting the need for longitudinal studies such as that of Geller et al as well as pathophysiological research in children, studies comparing adults and youth with bipolar disorder and studies of youth at familial risk for bipolar disorder," Dr. Leibenluft concludes.

This study was supported by a grant from the National Institutes of Health.