Abstract
Background: Clinical trials suggest long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA; 'fish oil') may reduce depressive symptoms in adults with MDD. Hence, n-3 PUFA may be a potential treatment for depression in youth.
Methods: Participants were aged 15-25 years with MDD who sought care in one of three government-funded mental health services for young people in metropolitan Melbourne, Perth, or Sydney, Australia. Participants were randomly assigned in a double-blind, parallel-arm design to receive 'fish oil' (840 mg of eicosapentaenoic acid and 560 mg of docosahexaenoic acid) or placebo capsules as adjunct to cognitive behavioural case management (CBCM). All participants were offered fortnightly 50-minute CBCM sessions delivered by qualified therapists (treatment as usual) at the study sites during the intervention period. The primary outcome was change in the interviewer-rated Quick Inventory of Depressive Symptomatology, Adolescent Version (QIDS-A17-C) score at 12 weeks. Erythrocyte n-3 PUFA levels were assessed pre-post intervention.
Results: 233 young people were randomised to the treatment arms: 115 participants to the n-3 PUFA and 118 to the placebo group. Mean change from baseline in the QIDS-A17-C score was -5.8 in the n-3 PUFA group and -5.6 in the placebo group (mean difference, 0.2; 95% CI -1.1 to 1.5; p=0.75). Erythrocyte PUFA levels were not associated with depression severity at any timepoint. The incidence and severity of adverse events were similar in the two groups.
Conclusions: This placebo-controlled trial and biomarker analysis found no evidence to support the use of fish oil for treatment in young people with MDD.
