Bipolar disorders neurobiology

Utility of Preclinical Models in Organizing Findings of the Neurobiology of Bipolar Disorder in Children and Adolescents... 

Ghaemi SN, Boiman EE, Goodwin FK. Kindling and second messengers an approach to the neurobiology of recurrence in bipolar disorder. Biol Psychiatry 1999 45 137-144. 

The neurobiology of bipolar disorder is less well studied than that of major depressive disorder. Early studies of monoamine metabolites found that they were increased in patients with bipolar disorder, but these were subsequendy inteiq reted as due to the increased motor acdvity seen in these padents. 

Bipolar disorder is characterized by episodes of mania or hypomania, which include hyperactivity, decreased need for sleep, and a euphoric or irritable mood. Additionally, persons with bipolar disorder may have episodes of depression similar to those seen in major depressive disorder. The lifetime prevalence of severe bipolar disorder is about 1% and 3-5% if milder cases are included, afflicting men and women equally. Both bipolar disorder and major depressive disorder tend to be episodic, and in the periods of time between episodes, persons may experience few or no symptoms. The etiology of bipolar disorder is predominately genetic, with a 70% concordance in monozygotic twins. The neurobiology of bipolar disorder is less well understood, and few animal models have been developed. Treatment of bipolar disorder usually involves mood stabilizer medications, including lithium, and the anticonvulsants valproate and carbamazepine. At times, antidepressant and antipsychotic medications are also used. 

Bezchlibnyk Y, Young LT (2002) The neurobiology of bipolar disorder Focus on signal transduction pathways and the regulation of gene expression. Can J Psychiatry 47(135) 48. 

In this chapter we review extant data on the neurobiology of unipolar and bipolar depressive disorders in children and adolescents. A complement to two recent reviews (Kaufman and Ryan, 1999 Kaufman et ah, 2001), this chapter places primary emphasis on those studies in which neuroimaging techniques have been used. Unfortunately, such studies are few and far between. Preclinical models that have guided research on the neurobiology of affective disorders in adults are discussed, and, given the limits in the application of these models to juvenile samples, especially in the case of unipolar disorder, the need for more developmentally focused preclinical work is emphasized. 

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