The worst recession in 70 years has meant soaring unemployment rates and plummeting moods. “Anxiety and depression seem to be a little more common in terms of what I’ve seen in the past six to 12 months,” says Michael Smith, ND, a naturopathic physician at Carolinas Natural Health Center in Matthews, N.C. “It’s easy enough to equate it with what’s happening in the economy.”

Roughly 14.8 million people—nearly 7 percent of the adult American population—suffer from a major depressive disorder, according to the National Institutes of Health. Even more U.S. adults—approximately 40 million—report anxiety disorders in any given year. A good percentage of these people don’t find relief through conventional medicine. Although Chicago-based research company Mintel reports that prescription depression medications continue to dominate the pharmaceuticals market with $12.9 million in 2007 sales (and anxiety meds not too far behind with $9.8 million in sales), researchers question whether many of these drugs are effective. The authors of a 2005 study published in Archives of General Psychiatry looked at 240 patients suffering from moderate to severe depression and found that half of study participants didn’t respond to conventional antidepressants. A recent Mintel study also found that 38 percent of respondents suffering from general anxiety turned to treatments other than prescription medications.

It’s no wonder, then, that sales of many natural ingredients for anxiety and depression posted upswings over the past year, even as consumers pinched pennies, according to SPINS, a Schaumburg, Ill.-based market research company. Four of the most popular natural options—fish oil, 5-HTP, docosahexaenoic acid (DHA) and S-adenosyl methionine (SAM-e)—enjoyed sales increases upwards of 15 percent in conventional stores. This year, get ready for more of your customers than ever to come looking for a natural mood booster. Here are five supplements you can recommend.

Fish oil
Fish oil is rich in omega-3 fatty acids, a major building block in optimal brain chemistry, says Paul Anderson, ND, a professor of naturopathic medicine at Bastyr University in Kenmore, Wash. Although Americans tend to get adequate amounts of omega-6 fatty acids from foods like canola oil and nuts, we often come up short in omega-3s, which are most readily available in cold-water fish. Without enough omega-3s, “you tend to not transmit nerve signals properly,” says Anderson. “When your brain isn’t running properly, you can feel depressed or anxious.” Scientists have come to the same conclusion: A 2007 study of 43 adults found that those with diets high in omega-6s but low in omega-3s had high levels of proinflammatory cytokines—molecules that tend to be produced in the body when people are depressed or stressed. However, the research on omega-3s and depression is still developing. One 2009 study found that higher intakes of omega-3s and oily fish may reduce the number of occasions that women suffer depressive symptoms by about 30 percent. However, another 2009 study showed that complementing antidepressant therapy with an omega-3 supplement did not improve depression levels in patients with coronary heart disease.

Tip: Some customers report an unpleasant aftertaste or “fish burps.” This usually can be avoided by making sure your fish oil is made from “clean,” pollutant-free fish. For those who don’t eat fish, Anderson recommends pure DHA supplements made from plant sources. Because of the lack of EPA in these supplements, the body doesn’t have to convert it into active DHA. Thus, opt for a dose that’s half the strength of a comparable fish-oil supplement.

B-complex vitamins
According to Anderson, one of the common culprits for mild depression is an imbalance of brain neurotransmitters—natural chemicals that can act as mood enhancers by helping transmit signals between brain cells. Prescription antidepressants like Prozac and other selective serotonin reuptake inhibitors (SSRIs) focus on one of these neurotransmitters in particular: serotonin, which they allow to stay around longer in the system. A more natural solution, says Anderson, is supplementing with vitamins B6 and B3 (niacinamide). “Basically, they make your body conserve the amino acid tryptophan and convert as much tryptophan as possible into serotonin.” A 2004 Danish study of 140 people found that those who were clinically depressed had low levels of vitamin B6 in their blood.

If upping serotonin levels through B6 and B3 doesn’t help, the problem might be a deficiency of the other two neurotransmitters in the brain: norepinephrine and dopamine. Anderson recommends turning to vitamin B12 plus folic acid, which are necessary for the synthesis of these two chemicals. A 2002 Dutch study of nearly 4,000 elderly people backs up this suggestion: Researchers found that many of those who had depression symptoms also had vitamin B12 deficiencies.
Tip: If a consumer is already on an SSRI, Anderson recommends consulting with a physician before adding supplements like B6 and B3 that manipulate serotonin.

5-HTP
The amino acid 5-hydroxytryptophan, or 5-HTP, is another natural option for upping serotonin levels. As a serotonin precursor, 5-HTP may help those for whom SSRIs like Prozac don’t seem to work, says Katie Baker, ND, owner of Stone Turtle Health, a naturopathic family medicine practice in Seattle. “SSRIs block the uptake of serotonin so it sticks around longer,” she says. But that won’t do much good if not much serotonin is around to begin with. In contrast, 5-HTP is converted into serotonin in the body. “With 5-HTP, you are not plugging up the drain, so to speak; you are just putting more into the sink,” says Baker. A six-week study of 63 people found that those who took 300 mg daily of 5-HTP had the same depression relief as those who took prescription antidepressants—but with fewer side effects.

Tip: Smith notes some people who take 5-HTP have loose stools, so he suggests taking a fat-soluble version, which usually comes in a spray form that’s largely absorbed before it reaches the digestive system.

Theanine
An amino acid derivative found in green tea, theanine has long been known to trigger the release in the brain of gamma-aminobutyric acid, or GABA. GABA activates the major calming neurotransmitters, promoting relaxation and reducing anxiety, but the body has difficulty absorbing supplements containing synthesized GABA. That’s why Anderson recommends theanine, which the body can easily absorb and, ultimately, use to boost levels of GABA.

Tip: Anderson doesn’t recommend doses above 600 mg without physician oversight.

Vitamin D
Vitamin D has long been championed for its ability to help maintain healthy teeth and bones because it promotes calcium absorption. Turns out the multitasking vitamin might also help combat anxiety and depression. A 2008 study of 441 overweight and obese men and women in Norway found that those given 20,000 and 40,000 IUs per week of vitamin D supplements had significantly less depression symptoms after one year than those in a placebo group. It’s unclear how, exactly, vitamin D might fend off depression, but Smith conjectures that it might improve neurotransmitter function.

Tip: Concerns about vitamin D toxicity have largely been put to rest. To be safe, however, Smith and Baker recommend a blood test to ensure patients’ serum 25-hydroxyvitamin D levels aren’t above the optimal ranges of 50 and 100 nanograms per millileter. Then they suggest a follow-up blood test three months after a patient begins supplementing with vitamin D.

Joel Warner is a Denver-based writer who opts for old-fashioned rock ‘n’ roll for his antidepressant of choice.