Adolescence is the highest risk period for depression onset. More than 1.3 million youths suffer from major depression annually in the United States, and there is evidence for an increasing trend. Because many adolescents have their first depressive episode in adolescence and adolescent depression often leads to recurrent mood disorders in adults, effective treatment during early illness can minimize the negative consequences of initial and repeated episodes. Although some antidepressants (particularly Selective serotonin reuptake inhibitors (SSRIs)) are effective treatments for juvenile depression, recent warnings about suicide and the use of SSRls highlight the need for new and safe treatment for juvenile depression. Data in adults suggest that supplementation with polyunsaturated fatty acids (PUFA) might be useful for the treatment of depression. The purpose of this study is to investigate the safety and efficacy of PUFA for the treatment of adolescent depression.