Major depressive disorder (or simply 'depression') is a serious mood disorder that causes persistent sadness and loss of interest in activities once enjoyed, often making it difficult for people with the condition to carry out their usual daily activities.
In addition to sadness and lost interest, common symptoms of depression include fatigue or lack of energy, changes in appetite, unintentional weight gain or loss, sleep problems, difficulty concentrating, feelings of guilt or worthlessness, or thoughts of suicide.
Treatment for depression typically includes psychotherapy (also called "talk therapy"), medication, or a combination of the two, according to Mayo Clinic. Certain lifestyle changes, such as a more nutritious diet, can also help people with depression feel better.
"Poor nutrition plays a major role in depression," says Deborah Serani, PsyD, psychologist and senior adjunct professor at Adelphi University in Garden City, New York. "Food is like a pharmaceutical compound that affects the brain. The more balanced you make your meals, the more balanced your brain will function," she says.
While a healthy diet is not a substitute for standard treatments for depression, it can still play an important role in managing and preventing symptoms. Research shows that a diet rich in fruits and vegetables, for example, is linked to a reduced risk of depression symptoms compared to diets high in anti-inflammatory foods such as red and processed meat and fast food.
While there is no specific diet that treatment guidelines recommend for people with depression, studies do suggest that regularly including the following six foods in your diet can improve your mood if you have the condition.
1. Fish
Research shows that vitamin D deficiency is linked to depression. People who consumed sufficient vitamin D experienced an improvement in depressive symptoms, according to a meta-analysis of 41 studies. That's good news for seafood lovers: fish - especially trout, tuna, salmon and mackerel - is rich in vitamin D.
Trout, tuna, salmon and mackerel are also rich in omega-3 fatty acids, which may also be linked to depression, especially in people with an omega-3 deficiency. According to a scientific study, regular consumption of foods rich in omega-3 fatty acids appears to ease depression in people who don't get enough of this nutrient.
Your doctor can help you determine if you have a vitamin or nutrient deficiency, and whether this may be making your depression worse.
2. Lean protein-rich foods
Research shows that there is power in lean proteins. Lean protein is known for its physical health benefits, including stronger muscles, better heart health and a greater chance of weight loss - but did you know it can also help improve your mental health?
Lean proteins can play an important role in regulating mood, says Dr. Serani. Although more research is needed on the role protein plays in treating depression, a study of nearly 18,000 American adults found that dietary protein intake reduced the risk of depressive symptoms.
Low-fat cheese and milk, eggs, chicken, turkey, fish, lean beef, low-fat Greek yogurt and beans are all good sources of lean protein, notes Serani.
These foods are also packed with vitamin B12, according to Mayo Clinic. "B vitamins can help protect and maintain the nervous system, including the brain, and may aid in overall mental health," says Scott Lyons, PhD, a psychologist in private practice in Florida.
Vitamin B12 also plays a role in the production of brain chemicals that influence mood, and a deficiency in this important nutrient may be linked to depression, according to Mayo Clinic.
3. Dark leafy greens
Another reason to fill your plate with dark leafy greens, which are known for their heart health benefits: Foods like spinach and kale are excellent sources of magnesium, which can help support a healthy mood, says Serani.
According to a systematic review of twelve studies, low magnesium levels are common in people with depression. Another study found that low magnesium intake was significantly linked to depression, especially in people under 65. That same study found that those who increased their magnesium intake had reduced depressive symptoms, especially in younger adults.
4. Green tea
Green tea is widely considered one of the healthiest drinks in the world and offers numerous potential benefits, including improved heart health, lower cholesterol levels and a reduced risk of cancer and diabetes.
Some research suggests it may improve mood because it contains the amino acid L-theanine, says Serani. L-theanine can have several positive effects on the brain and body, including increased focus, alertness, calmness and relaxation.
A small study showed that an additional dose of 250 milligrams (mg) of L-theanine per day for eight weeks, along with their usual medications, safely reduced symptoms in people with depression.
Because this was a small study, more research is needed to confirm these findings. But in general, there is little to no harm in adding one or a few cups of green tea to your day. However, be aware of the caffeine content in green tea, especially if you have heart or kidney problems. One cup of green tea contains about 28 mg of caffeine, according to Mayo Clinic.
5. Nuts and seeds
Nuts and seeds are not only delicious and satisfying, but they can also improve your mood.
This is partly because nuts and seeds are rich in L-tryptophan (sometimes simply called "tryptophan"). It's an essential amino acid that the body needs to make serotonin, a brain chemical involved in mood regulation and plays a key role in depression, says Serani.
A small study found that individuals who consumed high concentrations of tryptophan experienced significantly less depression, irritability, and anxiety than those who consumed lower amounts of tryptophan.
6. Ancient grains
Although "ancient grains" are a popular health word, the term has no official definition. The Oldways Whole Grains Council loosely defines ancient grains as grains that have remained largely unchanged over the past several hundred years (as opposed to foods like modern wheat, which have been bred and changed many times).
Ancient grains include whole grains such as spelt, barley, quinoa and buckwheat. These foods can help support mental health because they contain complex carbohydrates and have a low glycemic index (meaning they help maintain stable blood sugar levels), says Serani.
A large study of nearly 80,000 postmenopausal women showed that diets rich in high-glycemic foods (that is, foods known to cause a rapid rise in blood sugar levels, such as added sugars) may be associated with an increased risk of depression.
Another, much smaller study showed that participants who followed a high-glycemic diet were more likely to experience depressed mood over time than those who followed a low-glycemic diet. But a meta-analysis showed that consuming more complex carbohydrates (such as those found in ancient grains) can reduce the severity of depressive symptoms.
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