At baseline and all weekly visits, depression symptom severity was determined with the Children's Depression Rating Scale-Revised (CDRS-R), a 17-item observer-rated questionnaire, and remission was defined as a CDRS-R score of ≥28. If a patient's depressive symptoms worsened over the course of the trial (defined as 30% worsening relative to baseline on two consecutive visits using CDRS-R scores), they were withdrawn from the study. In view of the potential risk for developing hypomanic symptoms following LCn-3 fatty acid supplementation, manic symptom severity was monitored over the course of the trial with the Young Mania Rating Scale (YMRS), an 11-item observer-rated questionnaire.