Cause: Can be either psychologically caused, or due to chemical imbalance.

Useful Supplements: Folic Acid, Iron, Phenylalanine, Phosphatidylserine, Tyrosine, Vitamin B6, Vitamin B12.

Useful Herbs: Damiana, Ginkgo Biloba, St. John’s Wort, Yohimbe.

Further information: Depression can be caused by either a chemical imbalance (either natural or caused by medication such as oral contraceptives) within the system, or by outside stresses. While feelings of depression occur in most people, chronic depression, or long-lasting depressed spells, may need treatment.
Symptoms of depression include a depressed mood that lasts for most of the day, change of appetite and sudden gain or loss of weight, disturbed sleep, physical agitation, loss of interest in normal activities, fatigue, difficulty concentrating, feelings of worthlessness, and morbid or suicidal thoughts.
The cause and extent of depression are often the best indicators of which type of treatment is needed. If depression appears to be triggered by specific outside stresses, counseling is often the most effective method of coping. If, however, depression is severe and does not respond to counseling alone, medication may be necessary.
Some dietary changes have been shown to help in the treatment and alleviation of depression. In some cases, food allergies and sensitivities will cause individuals to have more intense bouts of depression.¹ See further information on food allergies for information on elimination diets and other ways to test for food allergy.
In most cases, there are two foods which consistently cause depression and mood swings to be more severe: sugar and caffeine.² Both should be avoided by those who are prone to depression.
Regular exercise appears to be helpful in the treatment of depression. Through exercise, the body produces endorphins, which are chemical mood enhancers. Routine exercise, even as little as three hours per week,³ can have a positive effect on mood.⁴

The following supplements and herbs may be effective in the treatment of depression:

The full class of B vitamins (including B6, B12, and Folic Acid) are often deficient in patients with depression.⁵ Some medications, such as oral contraceptives, deplete these nutrients in the body, making mood swings more common. Supplementation with Vitamin B6 is extremely helpful in the treatment of depression associated with oral contraceptives⁶ or pre-menstrual syndrome (PMS).⁷

Vitamin B12 is also effective when taken alone in combating depression.⁸ Even when B12 levels appear normal, the addition of a B12 supplement is often found to improve a patient’s mental state.⁹

Folic Acid deficiency has been found in many patients with depression. Taken in large amounts either alone¹⁰ or in conjunction with prescription medication,¹¹ it has shown promise in alleviating the symptoms of depression.

Low Iron levels are also often associated with depression – low iron leads to low energy, and lack of energy for daily activities can often lead to a depressed state. In such cases, iron supplements are often useful.

Phenylalanine is an amino acid which has been shown to improve moods in over 75% of a studied group of depressed patients.¹² It is especially effective when used in two forms: amino acid L-phenylalanine and its mirror image D-phenylalanine.¹³

Phosphatidylserine (PS) is derived from the amino acid serine. It affects neurotransmitters in the brain, causing more positive moods. In studies, women taking this supplement showed 60% less depression than those taking a placebo.¹⁴

Tyrosine is an amino acid which is needed in the creation of certain neurotransmitters which affect mood. Women who take oral contraceptives often have lower levels of Tyrosine; this is probably a major factor in depression associated with oral contraception.¹⁵ A twelve week Tyrosine supplementation has been shown effective in treating depression.¹⁶

St. John’s Wort is the most commonly used herb in the treatment of depression. While relatively "new" in the United States, it has been used in Germany for mild depression for many years.¹⁷ Patients show a marked improvement in as little as one week – far sooner than with most prescription medications. In addition, St. John’s Wort has far fewer side effects (mainly light sensitivity in fair-skinned patients). In some cases, patients respond as well to St. John’s Wort as to prescription medications.¹⁸

Gingko, Damiana, and Yohimbe show potential in the treatment of depression, but no studies have been completed on these herbs to date.

References:

¹King DS. Can allergic exposure provoke psychological symptoms? A double-blind test. Biol Psychiatr 1981;16:3–19.
²Christensen L. Psychological distress and diet-effects of sucrose and caffeine. J Applied Nutr 1988;40:44–50
³Martinsen EW, Medhus A, Sandivik L. Effects of aerobic exercise on depression: a controlled study. BMJ 1985;291:109.
⁴Martinsen EW. Benefits of exercise for the treatment of depression. Sports Med 1990;9:380–9.
⁵Reynolds E et al. Folate deficiency in depressive illness. Brit J Psychiatr 1970;117:287–92.
⁶Adams PW, Wynn V, Rose DP, et al. Effect of pyridoxine hydrochloride (Vitamin B6) upon depression associated with oral contraception. Lancet 1973;I:897–904.
⁷Gunn ADG. Vitamin B6 and the premenstrual syndrome (PMS). Internat J Vit Nutr Res 1985 (Suppl 27):213–24 (review).
⁸Lindenbaum J, Healton EB, Savage DG, et al. Neuropsychiatric disorders caused by cobalamin deficiency in the absence of anemia or macrocytosis. N Engl J Med 1988;318:1720–8.
⁹Ellis FR, Nasser S. A pilot study of vitamin B12 in the treatment of tiredness. Br J Nutr 1973;30:277–83.
¹⁰Di Palma C, Urani R, Agricola R, et al. Is methylfolate effective in relieving major depression in chronic alcoholics? A hypothesis of treatment. Curr Ther Res 1994;55:559–67.
¹¹Coppen A, Chaudrhy S, Swade C. Folic acid enhances lithium prophylaxis. J Affective Disorders 1986;10:9–13.
¹²Sabelli HC, Fawcett J, Gustovsky F, et al. Clinical studies on the phenylethylamine hypothesis of affective disorder: urine and blood phenylacetic acid and phenylalanine dietary supplements. J Clin Psychiatr 1986;47:66–70.
¹³Beckman H, Strauss MA, Ludolph E. DL-Phenylalanine in depressed patients: an open study. J Neural Transmission 1977;41:123–34.
¹⁴Maggioni M, Picotti GB, Bondiolotti GP, et al. Effects of phosphatidylserine therapy in geriatric patients with depressive disorders. Acta Psychiatr Scand 1990;81:265–70.
¹⁵Rose DP, Cramp DG. Reduction of plasma tyrosine by oral contraceptives and oestrogens: a possible consequence of tyrosine aminotransferase induction. Clin Chem Acta 1970;29:49–53.
¹⁶Gelenberg AJ, Wojcik JD, Growdon JH, et al. Tyrosine for the treatment of depression. Am J Psychiatr 1980;137:622–3.
¹⁷Harrer G, Sommer H. Treatment of mild/moderate depressions with Hypericum. Phytomed 1994;1:3–8.
¹⁸Vorbach EU, Hubner WD, Arnoldt KH. Effectiveness and tolerance of the Hypericum extract LI 160 in comparison with imipramine: Randomized double-blind study with 135 outpatients. J Ger Psyciatr Neruol 1994;7(Suppl 1):S19–23.