Fish oil has been known for quite some time to have beneficial cognitive effects. New research, however, is pointing to it even being capable of assisting with depression. Researchers from Harvard and The University of Melbourne collaborated to perform meta-analysis on data about Omega-3 fatty acids; finding solid evidence that it definitely does bolster effectiveness of anti-depressants. This snippet from 9News  gives the lead researcher’s opinions on their findings:
“Millions of people in Australia currently take anti-depressants. There’s real potential here to improve the mental health of people who have an inadequate response to them.”
He said the studies backed omega 3 fish oil for boosting treatment, while vitamin D, methylfolate (an active form of folic acid), and S-adenosylmethionine (sometimes used to treat osteoarthritis) were also proven to lift mood levels.
“We’ve realised previously that omega 3 is good for the brain health … and omega 3 was shown to be more beneficial than a placebo when combined with anti-depressants in improving depression treatment.”
However, experts don’t know the extent of the correlation between the supplement and the anti-depressant – whether it’s the interaction of the two substances that can help lift someone’s mood, or if just taking the supplement itself helps.
Which isn’t entirely correct. Case studies that this meta-analysis was built on, including this one  from the University of McGill, include strong anecdotal clues for it performing adequately on its own. The paper  itself, published in The Journal of Clinical Psychiatry, was originally intended to ascertain whether or not it was a viable treatment for bi-polar disorder. Regrettably, the manic-phase symptoms were not managed well by fatty acids.