In this parallel-group , relapse prevention , phase-@ study ( screening -LSB- @-day -RSB- , pali ER open-label run-in -LSB- @-week -RSB- and stabilization -LSB- @-week -RSB- phases , and double-blind ( DB ) treatment -LSB- variable duration -RSB- , and open-label extension phases -LSB- @-week -RSB- ) , @/@ patients with schizophrenia were randomized ( @:@ ) to pali ER ( @-@ mg ) or placebo during the DB phase .