Herbal Treatments and Supplements for Depression: The Bottom Line

Depression is a complicated illness, and there is a great deal of information (and misinformation) about the effectiveness of different treatment options out there. Alternative and complementary approaches are those used outside of more mainstream treatments. Though there is a wide assortment of alternate and complementary approaches that are pitched to treat depression, it’s important to keep in mind that research shows psychotherapy (i.e., talk therapy), mindfulness, exercise, and prescription antidepressant medication (in more severe cases) to be the most well understood and widely effective.

However, certain alternative treatments have been found to potentially alleviate depression symptoms in some cases.

It can be tough to distinguish unproven wellness fads and marketing ploys from legitimate treatments that can actually help, so we’ve gathered and reviewed the evidence for some common alternative and/or complementary treatments here:

St. John’s Wort

St. John’s wort is a popular herbal remedy for depression and mood disorders. The extract, derived from a wild plant, has been used medicinally in Europe for centuries.

Effectiveness:

A 2017 meta-analysis of 27 clinical trials found that for patients with mild-to-moderate depression, St John’s wort has comparable efficacy and safety when compared to SSRIs (a commonly prescribed antidepressant medication). However, evidence on the long-term efficacy and safety of St. John’s wort is limited as the duration of all available studies ranged from 4 to 12 weeks. It is also unclear if St John’s wort would be beneficial for patients with severe depression, high suicidality or suicide risk.⁽¹⁾

Possible side effects and interactions:

Side effects tend to be mild and can include: trouble sleeping, vivid dreams, difficulty sitting still, nervousness, irritability, stomach upset, tiredness, dry mouth, dizziness, headache, skin rash, diarrhea, and tingling skin.
St. John’s wort can cause serious interactions if taken with certain medications, including antidepressants, so it is important to consult your doctor before trying St. John’s wort if you are currently taking other prescription drugs.

The bottom line:

St. John’s wort limits the effectiveness of many prescription medicines. Combining St. John’s wort and certain antidepressants can lead to a potentially life-threatening increase in your body’s levels of serotonin, a chemical produced by nerve cells. St. John’s wort isn’t consistently effective for depression. Do not use it to replace conventional care or to postpone seeing your healthcare provider.

Ginkgo biloba

Ginkgo (Ginkgo biloba) is an antioxidant supplement derived from the leaves of the ginkgo tree, and has long been used in Chinese medicine. Ginkgo has anti-inflammatory properties and is known to increase blood flow to the brain, which could prove helpful in treating certain medical conditions, however, research on its effectiveness in treating depression has been limited.

Effectiveness:

A 2015 review of animal studies suggested that ginkgo may help decrease depression symptoms, however more research is needed to understand its effect on humans.⁽²⁾

Possible side effects and interactions:

Ginkgo extract is considered safe for most people. Side effects tend to be minor, and can include headache, dizziness, upset stomach, and allergic skin reactions.
Ginkgo can slow blood clotting, and should not be combined with ibuprofen or other medications known to also slow blood clotting. Gingko may also cause interactions with common prescription antidepressants including fluoxetine and buspirone.

The bottom line:

There is currently too little research supporting Ginkgo’s effectiveness at treating depression in humans. If you are considering taking Ginkgo supplements for other uses, make sure to consult a doctor beforehand to fully understand potential risks, side effects, and interactions with other medication.

Marijuana

Marijuana is a psychoactive drug derived from the cannabis plant which has long been used recreationally, and more recently medically, in order to treat certain conditions, such as pain and nausea associated with cancer treatments.

Effectiveness

THC, one of the two main active ingredients in cannabis, is a psychoactive substance which interacts with a system in our brains that plays a role in regulating our mood. This has led some to wonder if marijuana could be used to treat a mood disorder like depression. This is an interesting question, but because marijuana was only recently made legal in Canada and certain U.S. states, research is limited.

Possible side effects and interactions:

Side effects of smoking cannabis may include: headache, dizziness, drowsiness, dry mouth, nausea, increased appetite, increased heart rate, change in blood pressure, impaired mental functioning, and paranoid thinking.
Cannabis can interact with prescription medications including sedatives (barbiturates and CNS depressants) and certain antidepressant medications such as fluoxetine.

The bottom line:

The limited research we currently have indicates that use of marijuana is more likely to be associated with an increase in mental health problems rather than a reduction. For a more in-depth look at the current research, see our page on Marijuana and Depression.

Omega-3s (Fish Oil Supplements)

Omega-3s are fatty acids typically found in fish. When researchers found that rates of depression tend to be lower in countries where fish is commonly eaten, they wondered whether Omega-3s might be able to help treat depression.

Effectiveness:

Research on the effectiveness of Omega-3s for treating depression has been mixed. A 2015 systematic review found that omega-3 supplements were not effective in treating depression.⁽³⁾ However, another review which included 26 studies concluded that omega-3 supplements in certain dosages did have an effect in reducing depression symptoms.⁽⁴⁾

Possible side effects and interactions:

Omega-3 supplements are considered safe when taking standard doses. Side effects are uncommon and may include nausea and upset stomach. Because fish oil comes from seafood, it is unclear whether they are safe for people with seafood allergies. Fish oil supplements may also interact with drugs that reduce blood clotting, such as anticoagulant and antiplatelet medications, herbs, and supplements, so taking fish oil supplements with them may increase the risk of bleeding.

The bottom line:

There is little evidence to suggest that Omega-3s can treat depression; yet they are an important part of a healthy diet and are known to carry a number of health related benefits, including supporting brain health. If you are able to, the World Health Organization recommends 1-2 servings of fish per week as the best way to get enough Omega-3s. If unable to, supplementing with fish oil (typically sold in liquid gel capsules) is a good way to ensure you’re getting enough Omega-3s in your diet for your overall health.

SAM-e

S-adenosylmethionine, or SAM-e, is a molecule that naturally occurs in the body which is known to help support healthy bodily functioning. A synthetic form of SAM-e is sold as a supplement (in tablet form) in North America, and it has been sold as a prescription in parts of Europe for years.

Effectiveness:

The existing trials of SAM-e, used as monotherapy or added on to other antidepressants, have shown encouraging and generally positive results. However, more evidence is necessary before definitive conclusions can be drawn. Larger, double-blind randomised controlled studies are warranted to confirm the antidepressant effectiveness of SAM-e.⁽⁵⁾

Possible side effects and interactions:

SAM-e seems to cause minimal side effects, making it a possibly reasonable choice as an alternative or complementary treatment for depression.
Talk to your doctor before trying SAM-e, as it may interact with other medications including prescription antidepressants and supplements including St. John’s Wort, and may not be safe for people with certain conditions such as bipolar disorder, diabetes, and Parkinson’s disease.

The bottom line:

Overall, the evidence that oral SAM-e may be helpful for depression is not conclusive.

Vitamin D

Vitamin D is an essential nutrient that is vital for bone health, cell growth, and immune function. Our bodies produce vitamin D when we are exposed to sunlight, and it can also be found in certain foods including egg yolks, oily fish, and red meat. More recently, research has linked vitamin D deficiency with depression. ⁽⁶⁾
Risk factors for vitamin D deficiency include limited sun exposure, vegan and vegetarian diets, darker skin tone, obesity, and living at higher altitudes. If you think your depression symptoms may be the result of a vitamin D deficiency, you can talk to your doctor about taking a blood test to determine your blood’s vitamin D levels and consider taking vitamin D supplements.

Effectiveness:

A randomized clinical trial that included 18,353 adults over the age of 50 without depression at baseline found that supplementing with vitamin D3 compared with a placebo did not result in statistically significant differences in the prevalence and recurrence of depression, or change in mood scores over a 5-year treatment period.⁽⁷⁾

Possible side effects and interactions:

When taken in correct dosages, vitamin D supplements are unlikely to cause side effects. If too much is taken, side effects may include dry mouth, weakness, nausea, vomiting, and others.
Vitamin D interacts with aluminum, increasing the amount the body absorbs which can be an issue for people with kidney disease. Aluminum is found in most antacids, so it’s best to take vitamin D two hours before, or four hours after antacids.

The bottom line:

Supplementing with vitamin D can help those with a confirmed vitamin D deficiency; however, D vitamin supplementation has not been found effective for treating symptoms of depression.

B Vitamins (Folate, B6, B12)

B vitamins, including B6, B12, and folate are essential to healthy bodily functioning, and are important in supporting brain health and mood regulation. Studies have found that vitamin B deficiencies may contribute to depressive symptoms.⁽⁸⁾
Vitamin B is naturally found in many common foods but some people are prone to vitamin B deficiencies. Being over the age of 50, and/ or consuming a vegan or vegetarian diet puts you at a greater risk of developing a vitamin B deficiency, and symptoms include fatigue, weakness, nausea, confusion, irritability and depression.

Effectiveness:

A 2019 meta-analysis of 9 studies revealed a modest positive impact of B vitamin supplementation on depressive symptoms, but that the observed reduction failed to reach statistical significance (i.e., the observed effect was no greater than chance).⁽⁹⁾

Possible side effects and interactions:

Talk to your doctor before supplementing with vitamin B, as too much can cause a vitamin B overdose, with symptoms including nausea, vomiting, blurred vision, excessive thirst, and skin conditions.

The bottom line:

The use of Vitamin B supplements can be helpful for those with a confirmed Vitamin B deficiency; however, B vitamin supplementation has not been found effective for treating symptoms of depression.

References:

Ng, Q. X., Venkatanarayanan, N., & Ho, C. Y. (2017). Clinical use of Hypericum perforatum (St John’s wort) in depression: A meta-analysis. Journal of affective disorders, 210, 211–221. https://doi.org/10.1016/j.jad.2016.12.048
Montes, P., Ruiz-Sanchez, E., Rojas, C., & Rojas, P. (2015). Ginkgo biloba Extract 761: A Review of Basic Studies and Potential Clinical Use in Psychiatric Disorders. CNS & neurological disorders drug targets, 14(1), 132–149. https://doi.org/10.2174/1871527314666150202151440
Wani, A. L., Bhat, S. A., & Ara, A. (2015). Omega-3 fatty acids and the treatment of depression: a review of scientific evidence. Integrative medicine research, 4(3), 132–141. https://doi.org/10.1016/j.imr.2015.07.003
Liao, Y., Xie, B., Zhang, H., He, Q., Guo, L., Subramanieapillai, M., Fan, B., Lu, C., & McIntyre, R. S. (2019). Efficacy of omega-3 PUFAs in depression: A meta-analysis. Translational psychiatry, 9(1), 190. https://doi.org/10.1038/s41398-019-0515-5
Cuomo, A., Beccarini Crescenzi, B., Bolognesi, S. et al. S-Adenosylmethionine (SAMe) in major depressive disorder (MDD): a clinician-oriented systematic review. Ann Gen Psychiatry 19, 50 (2020). https://doi.org/10.1186/s12991-020-00298-z
Anglin, R., Samaan, Z., Walter, S., & McDonald, S. (2013). Vitamin D deficiency and depression in adults: Systematic review and meta-analysis. British Journal of Psychiatry, 202(2), 100-107. https://doi.org/10.1192/bjp.bp.111.106666
Okereke OI, Reynolds CF, Mischoulon D, et al. (2020). Effect of Long-term Vitamin D3 Supplementation vs Placebo on Risk of Depression or Clinically Relevant Depressive Symptoms and on Change in Mood Scores: A Randomized Clinical Trial. JAMA, 324(5):471–480. https://doi.org/10.1001/jama.2020.10224
Almeida, O. P., Ford, A. H., & Flicker, L. (2015). Systematic review and meta-analysis of randomized placebo-controlled trials of folate and vitamin B12 for depression. International psychogeriatrics, 27(5), 727–737. https://doi.org/10.1017/S1041610215000046
Young, L. M., Pipingas, A., White, D. J., Gauci, S., & Scholey, A. (2019). A Systematic Review and Meta-Analysis of B Vitamin Supplementation on Depressive Symptoms, Anxiety, and Stress: Effects on Healthy and ‘At-Risk’ Individuals. Nutrients, 11(9), 2232. https://doi.org/10.3390/nu11092232