The use of valproate in the treatment of mentally retarded persons with typical and atypical bipolar disorders.

The author reports five cases of bipolar disorder in mentally retarded adults that were managed by treating the patients with divalproex sodium, a valproate derivative. Two patients had chronic mania (one of whom had Fragile X syndrome), two patients had rapid cycling illness (one of whom had an autistic disorder), and one patient had a classic bipolar disorder superimposed on an autistic disorder. Four of the patients had marked responses to valproate and the fifth patient had a moderate response. Valproate blood levels were within the usual therapeutic range of 50 micrograms/mL to 100 micrograms/mL. These results demonstrate the effectiveness of valproate in the treatment of mentally retarded patients with typical and atypical bipolar disorders.