Double-blind 18-month trial of lithium versus divalproex maintenance treatment in pediatric bipolar disorder

Objective: To determine whether divalproex sodium (DVPX) was superior to lithium carbonate (Li+) in the maintenance monotherapy treatment of youths diagnosed with bipolar disorder who had been previously stabilized on combination Li+ and DVPX (Li+/DVPX) pharmacotherapy. Method: Youths ages 5-17 years with bipolar I or II disorder were initially treated with Li+/DVPX. Patients meeting remission criteria for four consecutive weeks were then randomized in a double-blind fashion to treatment with either Li+ or DVPX for up to 76 weeks. Study participation ended if the subject required additional clinical intervention or if the subject did not adhere to study procedures. Results: Patients were recruited between July 1998 and May 2002. One hundred thirty-nine youths with a mean (SD) age of 10.8 (3.5) years were initially treated with Li+/DVPX for a mean (SD) duration of 10.7 (5.4) weeks. Sixty youths were then randomized to receive monotherapy with Li+ (n = 30) or DVPX (n = 30). The Li+ and DVPX treatment groups did not differ in survival time until emerging symptoms of relapse (p = .55) or survival time until discontinuation for any reason (p = .72). Conclusions: DVPX was not found to be superior to Li+ as maintenance treatment in youths who stabilized on combination Li+/DVPX pharmacotherapy.