International research examines nutritional supplements for mental health

A meta-synthesis of evidence establishes the gold standard for nutrients proven to assist in the management of a range of mental health disorders, according to the new research published in World Psychiatry.

An international team of scientists from the NICM Health Research Institute at Western Sydney University in Westmead, Australia examined 33 meta-analyses of randomized control trials and data from 10,951 people with mental health disorders including depression, stress and anxiety disorders, bipolar disorder, personality disorders, schizophrenia and attention-deficit/hyperactivity disorder (ADHD). The aim was to provide a clear overview of the benefit of specific nutrient supplements, including dosage, target symptoms, safety and tolerability, across different mental disorders.

Although the majority of nutritional supplements assessed did not significantly improve mental health, the researchers found strong evidence that certain supplements are an effective additional treatment for some mental disorders, supportive of conventional treatment. All nutrient supplements were found to be safe when recommended dosages and prescriptive instructions were adhered to and there was no evidence of serious adverse effects or contraindications with psychiatric medications.

The strongest evidence was found for omega-3 supplements as an add-on treatment for major depression, reducing symptoms of depression beyond the effects of antidepressants alone, researchers said. There was some evidence to suggest that omega-3 supplements may also have small benefits for ADHD, as well as emerging evidence for the amino acid N-acetylcysteine as a useful adjunctive treatment in mood disorders and schizophrenia.

Special types of folate supplements may be effective as add-on treatments for major depression and schizophrenia, however folic acid was ineffective. There was no strong evidence for omega-3 for schizophrenia or other mental health conditions. Additionally, researchers found a is currently a lack of compelling evidence supporting the use of vitamins such as E, C, or D and minerals such as zinc and magnesium for any mental disorder.

Joseph Firth, PhD, lead author of the study and senior research fellow, said the findings should be used to produce more evidence-based guidance on the usage of nutrient-based treatments for various mental health conditions.

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

Jerome Sarris, PhD, senior author and professor, said that as the role of nutrition in mental health is becoming increasingly acknowledged, it was vital that an evidence-based approach be adopted.

"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," Sarris said in a statement. "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."