Divalproex-responsive rapid cycling bipolar disorder in a patient with Down's syndrome: implications for the Down's syndrome-mania hypothesis. 
A case of rapid cycling bipolar disorder in a person with Down's syndrome, responsive to divalproex sodium, a valproic acid derivative, is presented.  This case and three other reported cases of mania in association with Down's syndrome suggest that this chromosomal disorder does not preclude the development of mania.