Supplements & Mental Health: Is There a Link?

Supplements & Mental Health: Is There a Link?

If you or anyone you know suffers from mental health conditions such as depression, anxiety, ADHD, bipolar disorder or schizophrenia, you know how challenging managing daily tasks can be. Doctors have a whole host of medications they can prescribe to help manage mental health symptoms. Unfortunately, many of these medications have mild-to-serious side effects — and some aren’t particularly effective. Walk into any health food store and you’ll find a multitude of natural supplements that claim to relieve anxiety, depression, ADHD and other mental health conditions — but do they work? We’re going to review the latest research to see which supplements have been proven to have a positive impact on alleviating mental health symptoms.

Researchers at Australia’s Western Sydney University recently reviewed 33 high-quality randomized controlled trials that studied the efficacy of several popular supplements for treating conditions such as depression, bipolar disorder, ADHD and schizophrenia. The 33 studies had collected data from 10,951 individuals, with at least 75 percent having a confirmed mental health disorder. The researchers analyzed and compared the data to determine which supplements, if any, helped treat mental illness. All the supplements they compared were deemed safe and did not interfere with medications. They also wanted to find out which dosages were the most effective. They published their results in the journal World Psychiatry in September 2019.

Which Supplements Helped Treat Depression?

Most of the studies’ participants were taking prescription antidepressants, so nutritional supplements were considered an additional form of treatment.


Researchers found that omega-3 supplements with high levels of eicosapentaenoic acid(EPA) had small-to-moderate positive effects in treating depression. EPA is a type of omega-3 fatty acid found in the flesh of cold-water fish, including tuna, mackerel, herring, salmon, halibut, cod liver, seal blubber and whale blubber. Many fish oil supplements also contain docosahexaenoic acid (DHA), but the review found no mental health benefit from DHA supplementation.

Folate-based Supplements

Vitamin B9 is the most studied folate-based supplement. Vitamin B9 comes in several forms: folic acid, folinic acid and methyl folate (levomefolic acid, l‐methyl folate and 5‐methyltetrahydrofolate). Researchers found that some types were more effective than others at treating depression. At low doses, folic acid showed significant effects in some of the studies, but other studies found at high doses, it did not have much impact. High doses of methyl folate showed the most benefit for treating depression.

Vitamin D

Vitamin D is another widely studied supplement. The Australian researchers found evidence that Vitamin D supplements had some positive effects on treating depression. Doses needed to be at least 1,500 to 7,000+ IU per day to be beneficial. This should come as no surprise since it is well-documented that people who live in areas with minimal sunshine during winter months often suffer from a type of depression called seasonal affective disorder. Our bodies need sunlight to produce Vitamin D naturally.

N‐acetyl Cysteine (NAC)

N‐acetyl cysteine is the nutraceutical form of the amino acid cysteine. It is the precursor to glutathione, an antioxidant in our bodies that plays a role in detoxification. NAC is used as a treatment for acetaminophen (Tylenol) overdoses and carbon monoxide poisoning. Researchers found that NAC had small-to-moderate success in reducing depression symptoms.

Which Supplements Helped Treat ADHD?

Again, the researchers found that omega-3 comes out as a small winner in the treatment of ADHD in children. Sixteen of the studies reported on hyperactivity/impulsivity and inattention symptoms specifically. They found that parents reported significant benefits from omega-3 supplementation, but teachers did not. The researchers concluded that omega-3 supplementation (with high levels of EPA) showed small positive effects for reducing these ADHD symptoms, but did not impact emotional or behavioral symptoms.

Which Supplements Helped Treat Bipolar Disorder?

The best supplement for treating bipolar disorder is N‐acetyl cysteine, according to the review. NAC was found to have small but significant effects (compared to a placebo) on social and global functioning of bipolar patients. However, NAC did not lessen the severity of the illness overall.

Which Supplements Helped Treat Schizophrenia?

None of the supplements studied showed any significant impacts on treating schizophrenia. However, methyl folate (Vitamin B9) and N‐acetyl cysteine were found to reduce some schizophrenia symptoms when taken with medication.

Additional Observations and Conclusions Found in the Review

The Australian researchers who reviewed the 33 studies concluded that when compared to placebos, omega-3s, methyl folate, Vitamin D and N‐acetyl cysteine helped slightly in reducing symptoms in many mental health disorders. They drew other conclusions regarding diet and our gut microbiome.

Diet and Mental Health

Researchers were quick to point out that supplements cannot take the place of a nutritious diet. In fact, they stated that abundant evidence suggests that most people with mental health conditions eat unhealthy diets high in fat and sugar and low in nutrient-dense foods. Studies even suggest that an unhealthy diet usually precedes certain mental health conditions and increases the risk of developing depression.

How Does a Poor Diet Elevate Mental Health Risks?

correlation exists between many mental health disorders and heightened levels of oxidative stress and inflammationin the body. Oxidative stress happens when our bodies have too many damaging free radicals, which are created as a natural byproduct of cell energy production. Our bodies produce antioxidants naturally and we get them from the foods we eat. If our diets are low in antioxidant and nutrient-dense foods and high in sugar, our bodies can’t counteract the oxidative stress and prevent inflammation. Prolonged oxidative stress causes cell and tissue damage and inflammation, including in our brains. Many mental health disorders are caused or exacerbated by oxidative stress and inflammation.

Fortunately, lifestyle changes, certain foods and supplements such as omega-3s and N‐acetyl cysteine lower oxidative stress and inflammation. You can read more about which foods lower inflammation in our post, The Best Foods to Combat Inflammation and which foods contain healthy antioxidants in our post, Antioxidant Foods: Health Benefit or Hype?.  

Furthermore, evidence has found that people with mental health conditions often have reduced levels of essential nutrients such as Vitamin D, zinc and folate — another side effect of a poor diet.

An Unhealthy Gut Microbiome May Be Linked to Mental Health Disorders

Another factor the Australian researchers discuss in the review is the link between gut microbiome dysfunction and mental health. Growing evidence suggests that the balance and diversity of the bacteria in our gastrointestinal tract play a significant role in many health conditions, including mental health. Diets high in refined sugar, processed meats, fried foods and other highly processed foods lead to less microbe diversity. Read more about our gut microbiome in our post, Is Gut Bacteria the Solution for Optimum Health?

The takeaway from the Australian research team is that certain supplements can have a positive impact on reducing the symptoms of some mental health conditions. Factors such as an unhealthy diet and lifestyle contribute to nutritional deficiencies — which leads to or exacerbates some mental health disorders. Of course, you should always consult your doctor before taking any supplements, especially if you’re taking medication.


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