Since the early 2000s, supplementation of fish oil has significantly increased in part for the touted antidepressant effects. Many studies have found correlations between people who eat diets high in fish and lower incidences of depression. This has lead many Americans and others to look for ways to possibly mimic this antidepressant effect.
One shortcut to getting some of the potential mood benefit from fish is by taking “fish oil,” which contains two important omega-3 fatty acids: EPA and DHA. It is speculated that both of these fatty acids (especially EPA) tend to improve mood. However, there is an array of contradictory research and it’s really difficult for most people to decide whether they should supplement fish oil to help improve their depression.
Fish Oil for Depression: Research with Omega-3 PUFAs
There is an overwhelming amount of conflicting research in regards to using fish oil for the treatment of depression. It is important to realize that those who are most likely to benefit from taking supplements are people deficient in omega-3 fatty acid consumption. Additionally the amount of fish oil taken, quantities of EPA and DHA, as well as the quality of the supplement may play a role in determining whether it actually helps treat depression.
Like any treatment for depression, it should also be known that what works for one person may not work for another. Nonetheless, it appears as though fish oil is a minimal-risk antidepressant option to try assuming you are purchasing a quality brand. Below is a synopsis of the conflicting viewpoints and research on the usage of fish oil for the treatment of depression.
Evidence supporting fish oil as an antidepressant
Below is a summary of evidence in support of the usage of fish oil for the treatment of depression.
2014: In May of 2014, researchers Grosso et al. published a study in the journal PLOS One. They conducted a meta-analysis on the usage of omega-3 fatty acids for the treatment of depression. They specifically looked at randomized controlled trials (RCTs) with omega-3 PUFAs for the treatment of depression and objectively analyzed the outcomes among participants in these studies.
The studies they considered took place up until August 2013, and they used a variety of databases to gather these studies. The types of omega-3s utilized were mostly EPA and DHA. These studies consisted of people that were diagnosed with major depression as well as those who had depressive symptoms, but were not formally diagnosed.
Both the individuals that were formally diagnosed with major depression as well as those who were undiagnosed with depressive symptoms experienced significant improvements with omega-3 PUFA supplementation.
Authors noted that formulations with mostly EPA (rather than DHA) influenced the efficacy of the supplementation. They concluded that omega-3 PUFAs are effective among patients who have been diagnosed with major depressive disorder (MDD) as well as those who are depressed without a formal diagnosis.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/24805797
2014: Due to the fact that antidepressants can cause increased suicidality, some authorities recommend that they should be avoided at all costs for individuals under the age of 25. In 2014, Rice et al. suggested that long-chain omega-3 PUFAs (polyunsaturated fatty acids) are involved in a variety of psychological processes, holding potential to improve both physical and mental health.
Researchers in this study gathered evidence and realize that considerable past research has shown that supplementation could help individuals with depression. They decided to conduce a randomized, double-blind, placebo-controlled study by supplementing omega-3 fatty acids in the diets of youth with depression. The study lasted 12-weeks and consisted of 400 adolescents aged 15 to 25 all of whom had been diagnosed with major depression.
They divided the 400 participants into 2 groups: one group receiving CBT, and the other receiving omega-3 fatty acids (1.4 grams/day) plus CBT. The study found that omega-3 PUFAs provided a significant antidepressant effect and authors went as far as to say that they should be used as a “first-line therapy” in young people with major depression.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/25130262
2013: In 2013, Hegarty & Parker conducted a meta-analysis of evidence evaluating potential mood benefits that could be derived from omega-3 fatty acids. They highlighted the fact that many studies have cited low levels of omega-3 fatty acids among individuals with depression. They point out the fact that early studies of omega-3 formulations for depression found benefits, the findings in recent years haven’t been significant.
They believe that the reason for the inefficacy in recent findings has been due to DHA-dominant formulations. The authors emphasized support for EPA-centric formulations as well as highlighted the fact that fish oil may be a neuroprotective agent.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/23108232
2011: Researchers Lespérance et al. (2011) conducted a study in attempt to demonstrate the short-term effects of fish oil supplementation among those who were suffering from major depression. They set up a double-blind, randomized, and controlled, parallel group trial for an 8-week period. This included 432 patients from 8 Canadian psychiatric units that were randomly assigned to either 1.05 grams/day of EPA and 0.15 grams/day of DHA or were given a sunflower oil placebo.
The results were gauged based on the Inventory of Depressive Symptomatology as well as the MADRS (Montgomery-Asberg Depression Rating Scale). Results indicated that there was significant benefit of omega-3 PUFA supplementation among patients who experienced a major depressive episode (MDE). That said, individuals who had a depressive episode with comorbid anxiety didn’t experience “statistically significant” benefit.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/20584525
2003: An older study from 2003 conducted by Su et al. involved an 8-week double-blind, placebo-controlled experiment with omega-3 PUFA supplementation. They took 28 patients with major depressive disorder and assessed the severity of depression using the Hamilton Rating Scale for Depression (HAM-D). They then supplemented some of the individuals with 6.6 grams per day of omega-3 fatty acids or a placebo on top of their treatment. Results indicated that individuals receiving the omega-3 PUFAs experienced significant improvement in depressive symptoms and reported favorable tolerability.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/12888186
Evidence suggesting fish oil doesn’t treat depression
Below are studies that suggest fish oil is ineffective for the treatment of depression and/or is too risky to use for any medical condition.
2014: In a shocking publication, researcher Brian Peskin published an article “Why Fish Oil Fails” in the Journal of Lipids. In this piece, he highlights the studies that didn’t find any significant benefit associated with fish oil supplementation in 2013. He discusses the fact that fish oil tends to not only be “risky” to take over the long-term, but it likely produces no benefit in terms of treating heart problems, neurodegenerative disorders (e.g. Alzheimer’s), etc.
Although he doesn’t directly state that supplementation of omega-3 PUFAs produces no antidepressant effect, his review of evidence suggests that they are a risky supplement. That said, it should be noted that Mr. Peskin may have a conflict of interest as he works with supplement companies that create “rival” products to fish oil. Therefore some have viewed this publication as having significant bias and neglecting (a lot) of good science. It hsould be mentioned that this entire publication has since been “retracted.”
- Source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3914521/
2012: Bloch & Hannestad (2012) conducted a meta-analysis of randomized, placebo-controlled trials involving omega-3 fatty acid supplementation for the treatment of major depression. They looked at all placebo-controlled trials from 1965 up to 2010 and assessed the evidence. They also looked at the length of the trial conducted, methods, severity of baseline depression scores, and specific amounts of EPA and DHA administered.
Based on 13 trials that they analyzed with a total of 731 participants, they concluded that there was no significant benefit associated with omega-3 fatty acid supplementation compared to a placebo. They suggested that although there may be a small, insignificant benefit associated with omega-3 fatty acid supplementation, nearly all trials demonstrating efficacy may have been subject to publication bias.
- Source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3625950/
2009: Even among those who are not depressed, there is some evidence suggesting that supplementation of omega-3 PUFAs may be beneficial for mood and cognitive function. Researchers Antypa et al. conducted a study among 54 university students that randomly received either a fish oil supplement or a placebo for 4 weeks in a double-blind design. The goal was to determine whether supplementation with the omega-3 PUFAs could help improve depression-related cognition among healthy volunteers.
Researchers took note of: attention, cognitive reactivity, inhibition, memory, and risky decision-making. Results indicated that supplementation of the omega-3 PUFAs didn’t affect many functions, but did affect risky decisions. The supplementation also improved cognitive reactivity, but no effect on mood was found.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/18583436
2007: Back in 2007, researchers conducted a study using tuna oil (a form of fish oil) with a placebo among 83 individuals that were diagnosed with major depression. The study was double-blind, placebo-controlled, and took place for a period of 4 months. The researchers believed that deficiencies in omega-3 PUFAs may have been responsible for contributing to depressive symptoms and that supplementation may prove to be therapeutic.
They discovered that the tuna oil supplementation provided no benefit for the treatment of depression. The authors did note that although tuna oil was ineffective, other types of omega-3 PUFAs may be effective especially for individuals who are deficient.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/17659823
2005: In a randomized, double-blind, placebo-controlled study 77 participants were assigned to receive either 8 grams of fish oil per day or olive oil (as a placebo). Of the 77 participants, 59 of them managed to make it through the full 12 weeks of the study. All dietary and lifestyle factors were taken into account and mood was assessed using a shortened format of the Hamilton Depression Rating Scale and the Beck Depression Inventory.
Authors concluded that there was zero evidence in support of fish oil for the treatment of depression in comparison to a placebo. They even measured levels of circulating omega-3 and noted an increase. Mood did significantly improve after 2 weeks of the supplementation, but this effect wasn’t sustained over the course of 12 weeks.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/15664306
Verdict: High EPA Fish Oil Should be Tested
Based on a majority of scientific studies, it seems as though fish oil that is high in EPA is likely to be beneficial for those with major depressive disorder. Omega-3 PUFAs appear to be well-tolerated and yield minimal unfavorable side effects when taken at proper dosages. Supplements that contain over 60% EPA and/or considerably more EPA than DHA tend to be more effective.
A review of evidence suggested that amount of EPA should be between 0.20 and 2.2 grams/day more than the amount of DHA in a supplement for it to be effective in treating depression. If you suffer from depression and aren’t benefitting from first-line pharmaceutical drugs (e.g. SSRIs), you may want to consider taking a high-quality fish oil formula that consists of EPA.
At the very least you’ll find no major benefit from the fish oil, and at the very most the fish oil could end up significantly improving your depressive state. The good news is that fish oil supplementation has been shown to be beneficial as an adjunct treatment. Therefore if you are already taking an antidepressant, adding the fish oil may produce a greater overall effect.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/20439549
- Source: http://www.ncbi.nlm.nih.gov/pubmed/21939614
Potential Benefits of Fish Oil for Depression
Those that stand to gain the most benefit from taking fish oil for depression are those who don’t eat enough omega-3 fatty acids (e.g. fish) in their diet. Without enough omega-3 fatty acids, a person is more prone to depression.
- Adjunct option: If you are already taking an antidepressant, the good news is that fish oil can be supplemented for additional benefit. There are studies supporting the usage of fish oil as an antidepressant augmentation strategy. Always talk to your psychiatrist and/or doctor before doing this though.
- Balanced mood: Some studies have revealed that fish oil may help stabilize mood among individuals with bipolar disorder. In other words, it could help “balance” your emotions when taken over a long-term.
- Brain health: Even though EPA tends to be most beneficial for mood, there is some evidence suggesting that DHA may also play a role in improving brain health and function. Your brain is made up of fatty acids, which are building blocks for healthy activity and some of these come from fish oil.
- Cognitive function: There is also evidence suggesting that fish oil may help improve cognitive function. If you find that you are less impulsive, have better focus, and get more done during the day, it could be due to improved cognition.
- Less side effects: Compared to other drugs, fish oil is unlikely to have detrimental side effects. In fact, you may notice positive side effects such as improved mood, better cognition, and possibly even a little weight loss. Other antidepressant side effects can be a pain in the arse to deal with (e.g. sexual dysfunction/weight gain).
- Minimal withdrawals: There aren’t any major withdrawal symptoms associated with stopping fish oil. You may notice a reemergence of depression, but your neurotransmitters like serotonin won’t become deficient like they would when stopping an SSRI. Oddly enough, fish oil can actually help minimize withdrawal symptoms like “brain zaps” associated with stopping antidepressants.
Potential Risks of Fish Oil for Depression
While fish oil is generally well-tolerated to supplement, there are some risks to consider before taking it.
- Allergies: If you are allergic to fish or anything that’s in the supplement, you obviously shouldn’t be taking it. Most fish oils have warnings of potential allergic reactions on the bottle.
- Anxiety: Some have speculated that certain formulations of fish oil (with varying EPA/DHA) can cause increases in anxiety. There is conflicting evidence here though as some studies have found that fish oil is capable of reducing mental stress in men.
- Blood thinning: High amounts of fish oil taken on a daily basis can result in blood thinning. If you have any concerns about your dosage in regards to thinning of the blood, be sure to talk to your doctor.
- Prostate cancer risk: There are some studies linking fish oil consumption to increased risk of prostate cancer. While increased risk doesn’t indicate “causation,” it should be noted nonetheless.
- Worsening depression: Some people may experience an exacerbation of their depressive symptoms. While this is extremely unlikely, there are a few cases and self-reports that have surfaced.
- Source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3828934/
- Source: http://www.nlm.nih.gov/medlineplus/druginfo/natural/993.html
Factors to consider when supplementing fish oil for depression
It is important to note that there are many factors that could play a role in determining whether fish oil is likely to improve symptoms of depression. These factors include things like: individual physiology, dosage you take, how long you’ve taken it, the particular brand, amounts of EPA and DHA, as well as the purity of the product.
1. Individual basis
Whether fish oil works vs. doesn’t work will largely depend on the individual. Someone who is deficient in omega-3 fatty acids may notice an incredible benefit from its supplementation. Another person who eats plenty of fish may not need the excess EPA and DHA. Realize that like any treatment for depression, the responses will be subject to significant individual variation.
Your unique genetic code and physiology will influence the degree to which fish oil provides benefit. It should also be speculated that like any drug that influences your physiology, fish oil theoretically could even worsen your depression, while this is rare, it’s still a possibility.
2. Dosage
The recommended dosage for depression is between 2 grams and 4 grams of total omega-3 fatty acids daily. This isn’t the same as taking 2-4 grams of fish oil, it means that you should be taking enough fish oil to provide 2-4 grams of total omega-3 fatty acids (EPA+DHA) each day. Many people fail to get enough of the omega-3 fatty acids (the primary reason you’re taking fish oil to help with depression) from their supplement.
Taking 2 to 4 grams of “fish oil” is unlikely to yield 2 to 4 grams of omega-3’s. Read the label of the fish oil that you’ve bought and make sure that you’ll be taking enough to get the stuff (omega-3s) that actually has been found to help depression. You may want to experiment with the ratios of EPA and DHA that comprise the 2 to 4 grams as you may respond better to one than the other.
It should also be clear that 2 to 4 grams daily of combined EPA and DHA is one school of thought. Some practitioners are more aggressive in the amounts they recommend. I’ve read about significantly higher doses being tested with varying degrees of efficacy. Like any drug, it could take some time to work out the kinks and find an ideal dosage.
3. Duration
Like any antidepressant, you shouldn’t expect for it to work immediately. Some people may notice quicker benefits than others, but in general, don’t expect it to work overnight. You may not even notice that it’s doing anything after a week or two. Give the fish oil time and if it works, you may gradually notice that your mood has improved.
When fish oil starts working, you may not attribute the mood change to the fish oil, but it could be a direct result. Supplement it for two or three months daily and determine whether it’s working. Don’t be too quick to hop on the bandwagon saying that it doesn’t work unless you’ve actually given it a few months time.
4. Brand
The quality of product often depends on the particular brand that you buy. There are several good fish oil guides available as well as forum discussions that document the best quality products to buy. Unfortunately many of these guides are out-dated and much of the information is no longer relevant.
Be sure to first check if the company has undergone IFOS testing and is certified. Next, you may want to explore other independent testing companies to determine what they found. Keep in mind also that the particular subtype of fish oil you purchase from a company may result in varied efficacy.
Liquid fish oil is sold by certain companies (e.g. Carlson) and is thought to be better absorbed within the body. Some people swear by taking only the liquid version, but a disadvantage associated with the liquid oil is that it is more prone to rancidity and oxidation. On the other hand, some have argued that soft-gel formats may not be as good for absorption.
5. Amount of EPA and DHA
You don’t want your fish oil chock full of stuff that won’t help your brain. The amount of EPA and DHA are specifically what will help improve your mood. Some research suggests that EPA is probably more important than DHA when it comes to mood, and there are various formulations that tend to have more of one than the other.
As a starting recommendation, it would be advised to start with an EPA-dominant form of the oil. Most evidence for an antidepressant effect are derived specifically from EPA (eicosapentaenoic acid). That said, you may want to test out various formulations to determine which best suits your depression because some studies still suggest benefit from DHA.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/23733443
6. Purity vs. Rancidity
Many fish oils tend to oxidize quickly and often become rancid. As a good rule of thumb, if the fish oil smells rancid, it probably should be avoided. There is evidence that rancid fish oil could actually be causing additional harm. Absolutely stay away from any fish oil that smells a little “fishy” because it’s probably rancid.
Look for products that have been independently tested by the IFOS and ConsumerLab. Both will be able to inform you of brands to take and others to avoid. Taking rancid fish oil is going to do more harm than good so purchase your fish oil with caution.
Should Fish Oil be Used for Depression?
If you’ve tried an array of antidepressants and feel like a guinea pig with treatments for depression (e.g. antidepressant roulette), increasing intake of omega-3 fatty acids could be beneficial. There aren’t any major risks associated with supplementing fish oil unless you are taking a rancid or poor quality oil. Do your research and find a brand that has been internationally lab tested and is associated with a quality product, don’t just buy some cheap garbage from the store and assume it’s safe.
There have been cases of individuals who have found fish oil to be extremely beneficial for warding off depressive symptoms and/or stabilizing mood. It’s worth finding a quality brand and giving it a shot for at least 6 to 8 weeks (like you would a normal antidepressant) to determine whether you notice it working. You could also consider taking it as an adjunct option, as there is some evidence that it may produce beneficial effects when taken in combination with an SSRI.
It should be mentioned that there is already clear evidence suggesting a link between eating fish and antidepressant efficacy; those who eat more fish tend to have better outcomes. This could be in part due to the fact that increased omega-3 consumption offsets the effects of the high omega-6 intake of the standard American. If you aren’t eating the optimal diet for mental health, you may want to reassess what you’re eating and make an effort to include more fish, or at the very least, fish oil.
The risk of taking fish oil is low and the potential benefit is pretty great. Some people will find supplementation helpful, while others will not. Do not assume that just because fish oil alleviated your friend’s depression that it will do the same for you. Similarly, do not assume that just because fish oil didn’t do anything for another person that it cannot possibly work for you.
Give it a shot, keep an open mind, and best case scenario it’ll help improve your mood. If you have experience taking fish oil and have found it helpful (or non-helpful), feel free to share your comments below. For a more accurate understanding of your situation, mention the particular brand of fish oil you take as well as the daily amount.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/22198441