This multicenter , double-blind , randomized , placebo-controlled study investigated quetiapine XR ( dose range , @-@mg / day ) in pediatric outpatients with an American Psychiatric Association , Diagnostic and Statistical Manual of Mental Disorders , @th ed. , Text Revision ( DSM-IV-TR ) diagnosis of bipolar I or bipolar II disorder ( current or most recent episode depressed ) treated for up to @ weeks ( ClinicalTrials.gov identifier : NCT@ ) .