The aims of this multicenter , @-week , double-blind , randomized , placebo-controlled fixed-dose ( @ g/d ) trial conducted from @ to @ were to assess efficacy and tolerability of levothyroxine adjunctive to continuing treatment with mood stabilizer and/or antidepressant medication for patients with bipolar I or II disorder , currently depressed ( DSM-IV ) , and to investigate gender differences in treatment response .