A Double-Blind Placebo-Controlled Trial of Omega-3 Fatty Acids as a Monotherapy for Adolescent Depression

Objective: Reports are mixed on the efficacy of omega-3 fatty acids (O3FA) for the treatment of major depressive disorder (MDD), with only limited data in adolescents. The present trial aimed to investigate systematically the efficacy of O3FA as a monotherapy, compared to a placebo, in adolescents with MDD. Secondarily, we explored O3FA effects on anhedonia, irritability, and suicidality—all key features of adolescent MDD.

Methods: Fifty-one psychotropic medication-free adolescents with DSM-IV-TR diagnoses of MDD (aged 12-19 years; 57% female) were randomized to receive O3FA or a placebo for 10 weeks. Data were collected between January 2006 and June 2013. O3FA and a placebo were administered on a fixed-flexible dose titration schedule based on clinical response and side effects. The initial dose of 1.2 g/d was increased 0.6 g/d every 2 weeks, up to a maximum of 3.6 g/d. Clinician-rated and self-rated depression severity, along with treatment response, served as primary outcome measures. Additionally, we examined O3FA effects on depression-related symptoms, including anhedonia, irritability, and suicidality. Treatment differences were analyzed via intent-to-treat analyses.

Results: O3FA were not superior to a placebo on any clinical feature, including depression severity and levels of anhedonia, irritability, or suicidality. Additionally, response rates were comparable between treatment groups. Within-treatment analyses indicated that both treatments were associated with significant improvement in depression severity on self- (O3FA: t = -4.38, P < .001; placebo: t = -3.52, P = .002) and clinician (O3FA: t = -6.47, P < .001; placebo: t = -8.10, P < .001) ratings.

Conclusions: In adolescents with MDD, O3FA do not appear to be superior to placebo.

Trial Registration: ClinicalTrials.gov identifier: NCT00962598