A Study of Omega-3 as a Treatment for Major Depression

The study will be a 6 week, parallel-group, double-blind randomized controlled trial of the efficacy of Omega-3 as a monotherapy for depression. People aged 21-65 who have major depression but are not currently on an antidepressant or planning to take an antidepressant in the next 14 weeks will be recruited. Participants will be randomly allocated to receive Omega-3 (fish oil) or placebo (paraffin oil) for 6 weeks. Participants will be followed up weekly and will be asked to rate their mood daily for the 6 week study period. Blood samples will be taken pre and post treatment to measure change in omega-3 levels. At the end of 6 weeks all participants will receive a further 8 weeks supply of omega-3.