Magnesium for Anxiety and Depression? The Science Says Yes!

Hi, I’m Dr. Tracey Marks, a psychiatrist, and I make mental health education videos. Today, I’m talking about the critical role magnesium plays in your mental health that you probably didn’t realize.
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Magnesium is considered one of the essential minerals that’s involved in more than 300 different body processes, including keeping your heart beating and maintaining electrical stability of your nervous system. Magnesium is used by the body to regulate serotonin and other neurotransmitters, and some researchers believe that low magnesium is the problem behind treatment-resistant depression. How could that be? Well, magnesium is an NMDA receptor blocker.
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Blocking NMDA increases the brain chemical called BDNF, which is brain-derived neurotropic factor.
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BDNF is like fertilizer for the brain cells.
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Neuro means brain and trophic is Greek for feeding. BDNF is one of the chemicals that’s responsible for cell regrowth and neuroplasticity.
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Neuroplasticity is the ability to improve nerve connections by destroying damaged nerves and growing new ones. Think of it as neuro-flexibility.
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There’s another popular NMDA blocker called ketamine. Ketamine was approved as a medication for treatment-resistant depression in 2019. Ketamine is a hallucinogen, and so it’s not very easy to take for depression, but it works very fast by its powerful effect on increasing BDNF. I have a video talking more about ketamine for depression. Magnesium also helps anxiety, and here’s how.
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You have NMDA receptors in your amygdala. Those receptors control fear conditioning and avoidance behaviors.
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Avoidance is key in maintaining phobias. I talk a little bit about it in the video that I did on safety behaviors. So blocking the NMDA receptors in the amygdala and the rest of your limbic system decreases your fear response and avoidance, thus reducing anxiety. Another way magnesium helps anxiety is it decreases glutamate, which is a brain chemical that stimulates and excites the cells, and it increases GABA, which slows cell activity. Benzodiazepines and most sleeping pills work by increasing GABA.
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Now, you may be thinking if magnesium is so good and it’s already in our food, why would anyone be depressed or anxious? We all eat magnesium, right? Wrong.
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According to the National Institutes of Health, 68% of the population doesn’t eat enough magnesium, and that’s most of us, and therein lies the problem. Even if you consume enough magnesium, stress and anxiety deplete magnesium levels, and here’s how that works.
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When you have a physical stress, like an illness or anxiety, you get an increase in your sympathetic nervous system.
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You get elevated levels of cortisol and adrenaline. These elevations make you excrete more magnesium through your urine, so during times of stress and anxiety, even people with normal levels of magnesium can become temporarily magnesium deficient. In one of the studies that I have referenced in the description, the researchers saw this phenomenon when they studied a group of college students during final exams week.
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The students had normal levels of magnesium before the exams and became deficient while under the stress of exams. And if you have a temporary situation that can make your magnesium dip, you can recover when that stress goes away.
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But imagine the person who has an anxiety disorder or who’s depressed.
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That person becomes magnesium deficient, and the magnesium deficiency keeps them anxious and depressed.
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It’s like a loop that feeds on itself.
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So anxiety depletes your magnesium, and low magnesium makes you anxious or depressed. How much magnesium do you need? The recommended daily amount for men is 400 to 420 milligrams, and for women, it’s 310 to 320 milligrams, and it’s always best to get your vitamins and minerals from nutrient-dense food.
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Nutrient-dense food is food that has a lot of minerals relative to the calories.
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The highest natural source of magnesium is pumpkin seeds, carrying a whopping 156 milligrams for one ounce. Three ounces of cooked chicken breasts only contains 22 milligrams.
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There are good reasons to take supplements. Supplements are good if you just can’t eat enough through your food, or if you have digestion problems, and as we get older, we have less stomach acid, which can lessen how much of it you absorb. Another reason to take magnesium supplements is if you have depression or anxiety. Having those conditions suggests that you may still have reduced magnesium levels. Antidepressants do increase magnesium levels, but as I mentioned before, some people whose depression doesn’t get much better with antidepressants may be stuck in depression because of low magnesium. We still don’t have that much research evidence to support using magnesium as an add-on agent, so your doctor may not have recommended magnesium because nutrition and mental health are relatively new focus in medicine, but the research evidence is growing.
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Here’s what 225 milligrams of magnesium looks like, at least for the brand I use. They’re pretty big capsules, and it still doesn’t meet my daily requirement.
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I’d still have to eat my ounce of pumpkin seeds to get closer to my requirement. If you take other supplements, it can be a chore getting down all these pills. There are several different formulations of magnesium supplements.
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Here’s some of the popular options.
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Magnesium oxide has a lower absorption but a higher concentration of elemental magnesium.
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Because it’s not absorbed well, it can cause diarrhea. Sometimes it’s paired with calcium as a combination tablet, because calcium is constipating.
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Magnesium hydroxide is sold as the laxative called Milk of Magnesia.
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You don’t want to take it as a nutritional supplement, because you don’t want to have diarrhea every day. Magnesium citrate is the most common form of magnesium supplementation, and it’s better absorbed.
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Magnesium diglycenate and magnesium aspartate are more biologically available than magnesium oxide, but still less than the citrate version.
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Biologic availability refers to how much of the pill your body actually uses.
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Magnesium L-threonate is supposed to be more absorbed by the brain, but the research on this is still new.
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The most common side effect associated with magnesium is diarrhea, and you see this most often with the oxide and hydroxide forms. So that’s magnesium, an important nutrient for your brain health. If you haven’t already seen it, take a look at this video on gut health and depression. Thanks for watching. See you next time.