Everyone gets the blues from time to time. In fact, according to the National Institute of Mental Health, major depressive disorder (also known as depression) affects 7 percent of adult Americans every year, and chronic, mild depression affects 2 percent.

The good news is you may not have to turn to drugs to combat the blues. Of course, if bouts of depression continue for weeks at a time, you need to see a health-care professional and work out a treatment plan. But for occasional down days, adopting some simple lifestyle and diet changes and making them part of your daily routine can naturally boost your mood.

A regular dose of exercise may be just what you need to ease the first signs of depression or anxiety. A study by a team of researchers including Michael Babyak, professor of medical psychology at the Duke University Medical Center, showed that engaging in mild aerobic exercise three times a week was as effective as undergoing a standard treatment with antidepressant medications. While researchers aren’t sure why exercise helps, some speculate being active may affect brain chemicals or improve blood flow to the brain. Babyak says you don’t necessarily have to do extremely vigorous activity — even fast walking (try for 30 minutes at least three times a week) may help improve your mood.

 The foods you choose can also affect your mood. “Low levels or actual deficiency of such nutrients as omega-3 fatty acids, zinc, selenium, chromium, vitamin D, and the B vitamins folic acid and B12 are all associated with human depressive symptoms,” says Alan C. Logan, naturopathic physician and author of The Brain Diet (Cumberland House, 2007). However, Ronald Pies, M.D., clinical professor of psychiatry at Tufts University School of Medicine and professor of psychiatry at SUNY Upstate Medical University, Syracuse, adds that there’s no solid evidence to date that specific foods or nutrients can boost a person’s mood under normal circumstances. The key, he notes, is moderation. “A nutritious, well-balanced diet is very important for maintaining a normal mood.”

 Omega-3 fatty acids, found in fish, fish oils, and flaxseed, are being studied for their mood-boosting properties. Specifically, research suggests that eicosapentaenoic acid (EPA), an omega-3 found in oily fish, may be especially effective against depression. Though the jury is still out on all of the potential benefits of omega-3s, many experts say it’s worth giving them a try. “Consider adding more omega-3 fatty acids to your diet, if not to boost mood, then to improve your overall cardiovascular fitness,” says Ronald Pies, M.D., clinical professor of psychiatry at Tufts University School of Medicine and professor of psychiatry at SUNY Upstate Medical University, Syracuse. “This can be easily done by increasing your dietary consumption of certain fish, such as salmon or herring.” You can also get fish oil in supplement form.

When your body relaxes, it can help you see the world from a rosier perspective. One way to achieve effective relaxation is through the increasingly popular practice of yoga. Studies by India’s National Institute of Mental Health and Neurosciences have shown that certain yoga-linked breathing exercises can lower levels of cortisol, an adrenal hormone linked to stress. Another study found that immediately after a one-hour session, yoga practitioners had a healthy boost in levels of the mood-related neurotransmitter gamma-aminobutyric acid (GABA). Low brain levels of GABA have been associated with anxiety and depression. Yoga has many other health benefits as well.

Some people report that taking the herbal supplement St. John’s wort helps their depressive symptoms, while others find no benefit. Naturopathic physician and author Alan C. Logan says research has shown that it’s worth trying St. John’s wort if you have mild to moderate depression. He warns, however, that this herb shouldn’t be used if you’re already taking antidepressant medications. In addition, St. John’s wort can interact with many other prescription drugs, such as birth control pills, making them less effective. As a general rule, it’s always advisable to consult a health-care practitioner before using any nutritional supplement.

Getting your feelings out, be it in a letter or journal entry, or through creative writing, can provide insight into your feelings and give you perspective on how to let go of destructive emotions. James W. Pennebaker, Ph.D., professor and chair of the department of psychology at the University of Texas, says that although research about the value of expressive writing is still preliminary, regularly recording your emotional upheavals can improve both your physical and mental health. He recommends a writing session that lasts for a minimum of 15 minutes a day, on paper or the computer, for at least three or four consecutive days. Try to write continuously without worrying about spelling or grammar.

Research shows that a lack of sunlight during the dark winter months can cause a verifiable condition called seasonal affective disorder (SAD), or the winter blues. Alan C. Logan, naturopathic physician and author, says that even adults who don’t have SAD often report a decline in mood during this time. Greater exposure to natural sunlight can help combat this problem, as can the regular use of a full-spectrum light box. “The value of a light box has also been demonstrated even in healthy adults without SAD,” says Logan. Using the light box early in the morning (7 a.m. or earlier) may be most effective, he adds.

A massage by a skilled practitioner is not only rejuvenating for your muscles, it can also be a great stress and anxiety buster. A 2005 review of many research studies showed that massage therapy consistently lowered levels of the stress hormone cortisol in patients with various physical and psychological conditions. At the same time, it increased the activity of pleasure-related chemicals in the brain. Even if it’s not for therapeutic purposes, a massage can be enjoyable and decrease muscle and mental tension.

Trying to think positively, even during down times, can also affect your mood. Start by making a list of all the things in your life that you appreciate — the results may surprise you. Alan C. Logan, naturopathic physician and author, adds that being mindful (staying in the moment) can also help. He suggests you can do this by paying attention to your thoughts, emotions, and bodily sensations. “Taking stock of these mental events in a nonjudgmental way allows for the identification of negative patterns that can lead to depressive symptoms,” he says. “Research suggests that mindfulness may lead to resilience against stress and positively alter brain activity in the areas governing emotions.”

 Though your tendency may be to avoid people when you’re feeling down, often this can just add to feelings of isolation and depression. Reaching out to people, whether you discuss how you’re feeling or not, can help. Studies show that positive social ties can significantly protect a person’s health and well-being. So try to strengthen your relationships with people around you: Propose social dates, keep in touch with friends, explore volunteer opportunities, or take a new class. If your depression makes it too difficult to do these things, you should begin by reaching out to a doctor or therapist for some help.