Omega-3 supplements may reduce symptoms of major depression when used with antidepressants, according to Australian researchers.

In a review of research on nutritional supplements and mental health disorders, omega-3s stood out, reported Joseph Firth, Ph.D., Western Sydney University. Used as an add-on treatment for major depression, there was strong evidence that the supplements reduce symptoms beyond the effects of antidepressants alone.

Omega-3 supplements contain polyunsaturated fatty acids commonly found in fish oil. They appear to be safe in the recommended dosages and when used as directed. There was no evidence of adverse effects or contraindications with psychiatric medications, the investigators wrote.

Firth and colleagues advocate for an evidence-based approach to nutritional supplements in mental health care. The study examined 33 meta-analyses of randomized control trials and data from nearly 11,000 people with diagnosed mental health disorders. 

There was no strong evidence for omega-3 benefit in schizophrenia or other mental health conditions.

The study was published in World Psychiatry.