Science Update
October 24, 2006
New Research Helps to Improve Understanding of Bipolar Disorder in Youth
Bipolar disorder may be hard to identify in children and adolescents for several reasons, including a lack of age-appropriate diagnostic guidelines and symptoms different than those commonly seen in adults with the disorder. However, findings from two studies by NIMH-funded researchers, published in the October issue of the Archives of General Psychiatry, may help scientists to better understand bipolar disorder in youth.
David Axelson, M.D., of University of Pittsburgh, and colleagues found that three different classifications of bipolar disorder among youth—bipolar I, bipolar II, and bipolar disorder not otherwise specified (BP-NOS)—represent varying levels of impairment on a continuum, with elevated mood as a common feature of the bipolar spectrum illness in youth. Elevated mood was present in about 92 percent of youth diagnosed as having bipolar I disorder, as well as nearly 82 percent of those with BP-NOS. Youth with bipolar II disorder showed less functional impairment and were less likely to be hospitalized than those with bipolar I disorder, and also had higher rates of co-occurring anxiety disorders than those with either bipolar I or BP-NOS. According to the researchers, this is the first study to systematically assess and compare children and adolescents with these different types of bipolar disorder.
In another study, Barbara Geller, M.D., and colleagues at Washington University showed that prepubertal and early adolescent-onset bipolar I disorder appears to be the same illness as adult-onset bipolar I disorder. Previous studies have shown differences in symptom severity, frequency of cycling between manic and depressive episodes, and other aspects that raised questions as to whether bipolar disorder in youth was the same illness as in adults. Dr. Geller also demonstrated that bipolar disorder is significantly more prevalent in relatives of such affected youth, compared with relatives of youth with attention-deficit/hyperactivity disorder (ADHD) or healthy youth. In addition, the prevalence of bipolar disorder in relatives was significantly greater if relatives had co-occurring disorders, such as ADHD, oppositional defiant disorder, or conduct disorder, and for parents the age of onset of bipolar disorder was significantly younger if he or she also had ADHD. The prevalence of major depression was not significantly different between relatives of youth with bipolar disorder and ADHD, although in both of these groups the prevalence was significantly greater than that found in relatives of healthy youth.
Axelson D, Birmaher B, Strober M, Gill MK, Valeri S, Chiappetta L, Ryan N, Leonard H, Hunt J, Iyengar S, Bridge J, Keller M. Phenomenology of children and adolescents with bipolar spectrum disorders. Arch Gen Psychiatry. 2006 Oct;63(10):1139-48.
Geller B, Tillman R, Bolhofner K, Zimerman B, Strauss NA, Kaufmann P. Controlled, blindly rated, direct-interview family study of a prepubertal and early-adolescent bipolar I disorder phenotype: morbid risk, age at onset, and comorbidity. Arch Gen Psychiatry. 2006 Oct;63(10):1130-8.
