September 12, 2019
2 min read

Add-on nutritional supplements show potential for mental disorders

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

We were unable to process your request. Please try again later. If you continue to have this issue please contact

Image of Joseph Firth 2019
Joseph Firth

Data from a large meta-review published in World Psychiatry suggested that some nutritional supplements provided efficacious adjunctive treatment for specific mental disorders in certain conditions.

The strongest evidence supported omega-3, particularly eicosatetraenoic acid (EPA), as an effective nutritional intervention.

“Research such as this is important to bring together all the existing top-tier evidence, in order to establish where there is and is not sufficient basis for using nutrient supplements in psychiatric treatment,” Joseph Firth, PhD, senior research fellow at Western Sydney University’s NICM Health Research Institute, told Healio Psychiatry.

In their meta-review, Firth and colleagues compiled and examined all available data from meta-analyses of randomized controlled trials to determine the efficacy and safety of nutrient supplements in the treatment of different mental disorders. The review included 33 meta-analyses of randomized control trials and data from more than 10,000 individuals with ADHD, depression, anxiety disorders, bipolar disorder, personality disorders and schizophrenia.

The results showed that most nutritional supplements examined in the review failed to significantly improve mental health; however, certain supplements offered effective adjunctive treatment for some mental disorders when used alongside conventional treatment.

Image of fish oil 
Source: Adobe Stock

Specifically, the strongest evidence showed that omega-3s were effective when given as an adjunct to antidepressants in patients with depression and seemed to offer the greatest benefit when administered as high-EPA formulas. The data also indicated that omega-3 may offer the most benefit for patients with raised inflammatory markers. In addition, emerging evidence suggested that omega-3 supplementation may benefit patients with ADHD.

“An important finding is that there is currently no evidence to support the use of any nutrients as a first-line treatment or monotherapy for any psychiatric disorder,” Firth said. “Furthermore, the results show that previously indicated adjunctive supplement treatments are likely ineffective. For instance, the indicated efficacy of b-vitamin supplements in depression is driven mostly by large positive effects in early trials of high-dose methylfolate - whereas the typical forms of folic acid have no effects on depression or psychotic disorders.”

Firth and colleagues also found that adjunctive treatment with special types of folate-based supplements reduced symptoms of major depressive disorder and negative symptoms in schizophrenia, with positive effects from randomized controlled trials of high-dose methylfolate in MDD. Promising evidence supported the amino acid N-acetylcysteine as a potential adjunctive treatment in mood disorders and schizophrenia, according to the results.

The review also yielded good safety profiles for all nutrient supplements, without evidence of serious adverse effects or contraindications with psychiatric medications.

“The vast majority of nutrient supplementation trials to date have been conducted in populations with longstanding mental illness,” Firth told Healio Psychiatry. “Further research in the field should be dedicated towards examining the efficacy of potentially effective adjunctive treatments like N-acetylcysteine and L-methylfolate in young people in early stages of mental illness.” – by Savannah Demko

Disclosure: Firth reports support from a Blackmores Institute Fellowship. Please see the study for all other authors’ relevant financial disclosures.