A previous UK research has shown that omega 3 supplements don't work for people with depression, but it could if they combine it with antidepressants, according to new research.

Many health care professionals are believed to be aware of the effectiveness of certain supplements to health and well-being, but they are reluctant to recommend them for lack of sufficient evidence.

Today researchers from Harvard University and University of Melbourne reveal that while not all of these supplements are trustworthy, some warrant more attention. To be more specific, fish oil supplements with omega 3, vitamin D, S-adenosylmethionine (SAMe), and methylfolate may boost the job of antidepressants.

The new study is based on a review conducted on 40 different clinical trials involving the use of vitamins alongside three common antidepressants namely serotonin-norepinephrine reuptake inhibitors (SNRIs), selective serotonin reuptake inhibitors (SSRIs), and tricyclic antidepressants.

The data showed that "omega 3 fish oil – in combination with antidepressants – had a statistically significant effect over a placebo," said Dr. Jerome Sarris, meta-analysis leader.

Although the effects are less than that of omega 3, the other three supplements can still be helpful as adjunct mood-boosting therapies.

The team theorized that the efficacy may be brought about by the supplements' ability to lower inflammation, which has been linked to depression, and improve the pathways of neurotransmitters.

Sarris described these findings to be "exciting."

"We have a safe, evidence-based approach that could be considered a mainstream treatment," he said.

Further, the results suggest that nutraceuticals may help people with depression become more responsive to their treatment. So far, more than 14 million adults in the United States have major depressive disorder, and many of them won't experience remission even after several trials or treatment sessions, according to Sarris. 

The researchers didn't find any adverse side effect when these nutraceuticals were taken alongside the antidepressants, but they still advise patients to be cautious and seek advice from their doctors about the treatment.

While the news is great for fish oil and vitamin D, it isn't for vitamin C and zinc, which produced mixed results. The data also didn't show any positive effect for patients who took inositol and folic acid.

The study is now available in American Journal of Psychiatry.