Two cases of bipolar disorder successfully stabilized for five years with a low dose of risperidone and lithium.

Two patients with bipolar I disorder were successfully treated with a combination of risperidone and lithium in their acute manic states and maintenance periods. Although lithium monotherapy alone could not prevent relapse in these patients, the addition of a low dose of risperidone was well tolerated and effective for preventing recurrence over the long term. Plasma levels of HVA and MHPG were found to be elevated during the manic episodes and gradually decreased after the risperidone treatment. These results indicate that a low dose of risperidone to the lithium regimen was an effective and well tolerated means for treatment in the acute manic state and the later maintenance period in parallel with decreasing plasma levels of HVA and MHPG.