Abnormalities in Developing Adolescent Brain Seen in Bipolar Disorder

Marlene Busko

May 12, 2008

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Interview with Dr. Blumberg

May 12, 2008 (Washington, DC) — Preliminary brain-imaging findings of differences in the amygdala and in the prefrontal cortex in brains of teens with bipolar disorder suggest that this disorder develops in adolescence and that future treatments might be able to reverse or halt the progression of brain changes, Hilary P. Blumberg, MD, from Yale University School of Medicine, in New Haven, Connecticut, said in a press conference at the American Psychiatric Association 61st Annual Meeting.

Vulnerable Adolescents with Genetic Predisposition

"Adolescence may be a very important time in developing bipolar disease, a time when those with genetic predisposition to the disorder may be at high vulnerability for developing the disorder as the adolescent brain changes," she said.

"But the flip side, which I think is very hopeful, [is that] because the brain is still dynamically changing over the adolescent period, there is an important opportunity to reverse changes, [and] there's some very preliminary evidence that treatment may help reverse structural and functional abnormalities and prevent progression," she noted.

"We are very hopeful that on horizon, with lots of work, this will lead to the ability to prevent this disorder," she said.

Preclinical investigations by other researchers have shown that medications for mood stabilization and for bipolar disorder may help facilitate the growth of nerve cells, Dr. Blumberg told Medscape Psychiatry. These findings complement the preliminary findings from her group, she noted.

"I think that we've made a lot of progress in finding the parts of the brain that are important," she observed, adding that other important research is aimed at elucidating the genes involved in this highly heritable disorder.

Changes in the Amygdala and Prefrontal Cortex

Dr. Blumberg and colleagues showed differences in mood disorders in 2 nodes in the brain's emotional circuitry: the amygdala and the prefrontal cortex.

Using magnetic resonance imaging (MRI), they showed that the amygdala — which is important in processing emotions — is smaller and had a different structure in individuals with bipolar disorder. Using functional MRI (fMRI), they and other researchers found adults and adolescents with bipolar disorder had an exaggerated response of the amygdala to emotional stimuli.

They also found evidence suggesting that the volume of the prefrontal cortex — which plays an executive role in regulating emotions — decreases over the adolescent period in individuals with bipolar disorder.

The emergence of prominent symptoms of bipolar disorder in adolescence at a time when the brain is changing suggests that abnormalities in brain circuitry during adolescence are implicated in bipolar disorder, Dr. Blumberg said.

"The findings provide important new leads that may help in the development of new ways to detect the disorder earlier, to provide more effective treatments, and hopefully to someday prevent the disorder," she said.

Other "exciting" genetic research may help identify new treatment strategies aimed at the molecular mechanisms associated with genes that affect brain circuitry, she added.

Dr. Blumberg has acted as a consultant for Pfizer and has received speaker honoraria from Eli Lilly and Abbott Laboratories.

American Psychiatric Association 161st Annual Meeting: Symposium 35. May 3-8, 2008.


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