A major clinical study in Montreal will try to pinpoint the effectiveness of Omega-3 in the treatment of depression.

The study's size is unprecedented, and will be carried out by the centre hospitalier de l'Université de Montréal (CHUM).

Preliminary studies are already underway, and suggest there is a link between a diet low in omega-3 fatty acids, which are found in some fish, and some psychological problems.

The eight-week study, will include 508 people in Quebec and Ontario who have been diagnosed with severe depression. In the double-blind study, part of the group will get a placebo, while the others will get concentrated fish oil supplements.

Researchers are trying to find a treatment that could replace or complement anti-depressants.

Funding for most of the work will be provided by Isodis-Natura, a European company founded by David Servan-Schreiber, a psychiatrist and ardent promoter of the virtues of omega-3.

Despite the source of financing, and the fact that Isodis-Natura sells an omega-3 supplement in Quebec, CHUM is confident it will have the freedom to carry out a thorough and accurate study.

David Servan-Schreiber will act as a consultant for the CHUM research team.

The results are expected in Oct. 2007.

Omega-3 fatty acids are also thought to protect against heart disease and cancer.

The Heart and Stroke Foundation of Canada recommends people eat at least two to three servings of fish a week.