Supplements A Viable Treatment For Depression: Study

Researchers have weighed up the evidence when it comes to which nutrient supplements are effective in the treatment of mental health disorders.

It's a question that has been around in medical fields for quite some time -- if there is a relationship between poor diet and mental illness, what benefit is there to nutrient supplementation when treating mental disorders?

Now, a group of international scientists has undertaken the world's largest evidence review into the topic, examining the "best of the best" available research.

The study, led by Sydney's NICM Health Research Institute, determined that while the majority of nutritional supplements assessed did not significantly improve mental health, there is strong evidence that certain supplements are an effective additional treatment for some mental disorders when taken alongside traditional treatment.

"This mass of data has allowed us to investigate the benefits and safety of various different nutrients for mental health conditions - on a larger scale than what has ever been possible before," said lead author of the study Dr Joseph Firth.

“While there has been a longstanding interest in the use of nutrient supplements in the treatment of mental illness, the topic is often quite polarising, and surrounded by either over-hyped claims or undue cynicism."

The evidence review, published on Tuesday in World Psychiatry, examined 33 meta-analyses of randomised control trials and data from almost 11,000 people with mental health disorders -- including depression, stress and anxiety disorders, bipolar disorder, personality disorders, schizophrenia, and ADHD.

According to the study, the greatest evidentiary support can be found for the use of omega-3 supplements.

When used as an add-on treatment, the nutrient has been noted to reduce symptoms of depression beyond the effects of antidepressants alone.

"Meta-analytic data have shown that omega-3 is effective when given adjunctively to antidepressants," authors wrote in the study.

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There was also evidence to suggest omega-3 -- which is naturally found in foods including fish and chia seeds -- may have "small positive effects" when treating ADHD symptoms.

As for the use of vitamins, including E, C or D, or minerals such as zinc and magnesium, researchers determined there is currently a lack of evidence supporting their use to improve the symptoms of any mental disorder.

Dr Firth hopes the findings will be used to produce even more evidence-based guidance on the usage of nutrient-based treatments, as well as provide a clear overview on what is known when it comes to dosage, target symptoms, safety and tolerability.

“Future research should aim to determine which individuals might benefit most from evidence-based supplements and to better understand the underlying mechanisms so we can adopt a targeted approach to supplement use in mental health treatment,” Senior author on the study, NICM Health Research Institute’s Professor Jerome Sarris said.

“The role of the gut microbiome in mental health is a rapidly emerging field of research, however, more research is needed into the role of ‘psychobiotics’ in mental health treatment.”