Overview 

Clinical depression, also referred to as major or unipolar depression, is the most commonly occurring mood disorder and cause of disability that affects approximately 17 million Americans.

While nearly everyone experiences ‘the blues’ on occasion, these feelings are usually associated with a life event and are only temporary, passing within a short time. However, when a true depressive disorder is present, the person may be unable to function and daily life may be negatively affected. Personal relationships, work, school and overall health may suffer.

Depression is a real disease and not just a state of mind. In other words, one cannot simply ‘snap out of it.’ Furthermore, depression can manifest physical symptoms, such as muscle aches or general pain of nonspecific origin.

Unfortunately, many people with depression do not seek medical treatment and remain undiagnosed. However, depression can be treated and managed with appropriate intervention. 

Types of Depression

Major depressive disorder.  Also referred to as major depression, this form of depression is debilitating. Activities once found pleasurable are abandoned and everyday functioning becomes very difficult. While it is possible for a person to experience an isolated period of major depression, it is more common for people with major depressive disorder to experience recurring bouts throughout their lifetime.

Bi-polar disorder.  Also known as manic-depression, bi-polar disorder is characterized by extreme mood swings that range from high periods of mania to deep deep depression.

Post-partum depression.  Approximately 10-15% of women experience a major depressive eposide within one month after giving birth.

Seasonal affective disorder.  Simply dubbed as SAD, seasonal affective disorder occurs in reponse to reduced exposure to sunlight during the winter months. Generally, this depressive illness fades during spring and summer months.

Dysthymia.  Dysthymia is a depressive disorder with characteristics similar to major depression, but of less severity and lasting for prolonged periods of at least two years.

Psychotic depression. This form of depression is chronic and is accompanied by psychosis, such as a nervous breakdown, hallucinations, etc. 

Symptoms and Diagnosis 

Diagnostic guidelines for clinical depression are outlined by the American Psychiatric Association in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). According to the DSM-IV, at least five of the following eight symptoms must be present for at least one month in order to diagnose clinical depression:

- Weight loss due to a poor appetite, or overeating accompanied by weight gain
- Frequent insomnia or hypersomnia (sleeping too much)
- A lack of interest in regular activities and/or a decrease in sex drive
- Overall feeling of fatigue
- Excessive activity or inactivity
- Feelings of worthlessness or guilt
- Difficulty concentrating
- Suicidal thoughts

In addition, the following conditions must be met:

-          Symptoms presented are not secondary to a combination of psychiatric episodes.

-          Symptoms are affecting work, home, school or social functioning.

-          Symptoms are not related to substance abuse.

-          Symptoms are not related to normal bereavement due to the loss of a loved one or family member.

Causes and Risk Factors

The exact cause of major depression is still largely unknown. However, there is evidence to suggest that hormonal imbalances and, possibly, a genetic predisposition may be significant factors. For instance, people afflicted with depression show decreased levels of mood-altering hormones, such as serotonin and dopamine. In addition, some studies indicate that depressive disorders coincide with altered brain structure, especially in the hippocampus. Some researchers believe that oxidative stress may contribute to depression by damaging DNA in brain cells. Further, some studies indicate that depression is linked to vascular and cerebrovascular disease. 

Depression is more common in women than it is in men. However, men are more inclined to turn to substance abuse to cope with their depression and are more likely to exhibit violent tendencies. Children and adolescents are not immune to depression. In fact, research indicates that the first episode of depression often occurs in childhood and, when it does, is likely to persist into adulthood. Emotionally troubled adolescents, in particular, are at an increased risk for depression, substance abuse and suicide.

Treatment of Depression

Anti-depressant drugs are an all-too-frequent course of treatment for depression, but are not necessarily the best. For one thing, there is a high rate of relapse and dependency associated with these drugs. In addition, in 2004 a federal advisory panel released its findings in on the safety and effectiveness of one of the most common form of medications prescribed for depression--selective serotonin reuptake inhibitors (SSRIs). The panel found that SSRIs increase the risk of suicide in children and adolescents. The following year, the Federal Drug Administration (FDA) adopted these guidelines and subsequently issued strong warnings against the use of SSRs in treating depression in this age group.

Various forms of psychotherapy are also used in the conventional treatment of depression. One complimentary therapy gaining in popularity is cognitive therapy, which serves to manipulate brain chemistry by empowering the patient with new “tools” for daily living. In effect, cognitive therapy teaches the depressed person to replace automatic negative thoughts with more appropriate ones. This restructuring of thought processes not only relieves the feeling of helplessness or loss of control in the patient, but may also assist in stabilizing brain chemistry.

Recommended Supplements in the Treatment of Depression

DHEA

DHEA, or dehydroepiandrosterone, is a steroid hormone normally found in abundance in the brain. However, people with depressive disorders usually exhibit low levels of this mood-altering substance. DHEA levels also decrease with age. Several studies have shown that DHEA helps to regulate serotonin release, and that supplementation with DHEA can help to improve symptoms of depression. 

SAM-e

Sam-e (S-Adenosyl-Methionine) is involved in the functioning of monoamines (such as serotonin, dopamine and gamma-amino-butyric acid or GABA), neurotransmitters and certain serum lipids. In “normal” brain chemistry, sufficient amounts of SAM are produced by the amino acid methionine, but this synthesis is impaired in depressed individuals. Numerous double-blind, placebo-controlled studies have found SAM to be one of the most effective natural anti-depressants and is better tolerated and works faster than many tricylic anti-depressant drugs. While SAM has been widely used in Europe for at least 20 years, it has only arrived in the U.S. within the last few months.

Note: SAM supplementation is not suitable for manic (bipolar) depression patients as their manic symptoms may escalate.  

L-tryptophan

L-tryptophan is the metabolic precursor of serotonin and melatonin, neurotransmitters with sedative qualities and useful in the treatment of depression symptoms. However, L-tryptophan was banned in the U.S. due to an incidence of contamination and the Food and Drug Administration isn’t likely to allow it back on the market any time soon. But, a newly available supplement, 5-hydroxytryptamine (5-HTP), may be even more effective. Unlike L-tryptophan, 5-HTP is readily bioavailable since it does not require a transport molecule or compete with other amino acids in the system. While it was necessary to take L-tryptophan on an empty stomach, 5-HTP can be taken with meals. In addition, 5-HTP is biochemically closer to serotonin, chemically known as 5-hydroxy tryptamine. Studies have also shown that 5-HTP elevates beta-endorphins, the “feel good” hormones.  

Omega-3

According to the American Journal of Clinical Nutrition, there is a clear association between depression and a diet lacking in sufficient essential fatty acids, specifically, omega-3. The brain depends upon fatty acids to ensure membrane fluidity and nerve cell function, factors that effect neurotransmitter synthesis and transmission. Low omega-3 levels also influence the action of monomine oxidase, the enzyme responsible for breaking down serotonin, epinephrine and dopamine. The best sources of omega- fatty acid are cold water fish, such as salmon, halibut, etc., consumed 1-2 times per week. Supplementation with fish oil, a rich source of omega-3, should include docosahexanoic acid (DHA) and eicosapentaenoic acid (EPA). Follow the manufacturers dosage recommendations.  

Folic Acid

Several studies have shown that folic acid improves the symptoms of depression. In addition, supplementation with folic acid has also been shown to increase the benefits of antidepressant medications in adults.   

Vitamin B12

An elevated level of homocysteine is associated with an increased risk of developing depressive disorders. Low levels of vitamin B12 (cobalamin) plays a role in increased homocysteine production, which can be influenced by vitamin B12 supplementation, especially in older patients who tend to have a deficiency in this vitamin. 

Vitamin B6

A review of clinical trials involving vitamin B6 (pyridoxine) by Yale University revealed that premenopausal women prone to depressive episodes were positively affected by supplementation with this vitamin.

Herbs Used in the Treatment of Depression

St. John’s Wort

There are at least 10 pharmacologically active constituents found in the extract of this herb, but researchers are most interested in hypericin and pseudohypericin. The exact mechanism of the herb’s ability to alleviate depression and anxiety remain largely unknown, but a recent study may provide some clues. The action of hypericin at alpha receptor sites, known to be involved in the role of MAOs and 5-HTP reuptake inhibitors (a metabolite of L-tryptophan in the synthesis of serotonin), lends support to the herb’s universal reputation as a mood elevator and sedative.

Kava

This herb has a long history of use in reducing anxiety, but is relatively new in the treatment of anxiety-related depression. Several European countries have approved kava for the treatment of insomnia, nervous disorders and depression. In the U.S., kava preparations are available as dietary supplements. The beneficial agents of kava are kavalactones found in the dried rhizome of the plant. Several studies have shown that kava effects a GABA-receptor-binding capacity and an ability to block norepinephrine uptake. In a 1997 German study, 101 subjects suffering from non-psychotic anxiety took part in a 25 week placebo-controlled, double-blind trial with an extract of kava. The researchers concluded that kava is comparable to treatment with benzodiazepines but without unwanted side effects.

Ginkgo Biloba

Ginkgo biloba provides antioxidant properties. In studies using animal models, treatment with this botanical reduced the incidence and severity of depressive symptoms when the subjects were exposed to chronic stress. When the same study subjects were treated with the antidepressant drug venlafaxine, ginkgo extract provided protection from negative side effects.

Safety Precautions 

DHEA

Do not take if you are pregnant or nursing.

Do not take if you have prostate, ovarian, uterine or breast cancer.

May produce androgenic effects in women, such as deepening of the voice and facial hair.  

SAM-e

Do not take if you are undergoing cancer treatment or gene therapy.

Consult with your physician if you have bipolar disorder. 

L-tryptophan

Do not take in conjunction with type A monoamine oxidase inhibitors (MAOIs), serotonin 5-HT receptor agonists, or any other type of antidepressant medications.

Do not take if you carcinoid tumors or cardiovascular disease. 

Omega-3

Do not take if you are currently taking warfarin (Coumadin) due to an increased risk of bleeding.

Discontinue use two weeks before and after any surgical procedure. 

Folic Acid

Consult with a physician before taking if there is a possibility that you may have a vitamin B12 deficiency.

Vitamin B12

Do not take if you have Leber's optic atrophy. 

Vitamin B6

Consult with a physician if you are currently taking levodopa. 

St. John’s Wort

This herb can sometimes cause mild stomach irritation.

Hypericin may increase photosensitivity and has been recently linked with the formation of cataracts with long-term use. 

Kava

Do not take with benzodiazepines, sedatives, barbiturates or Xanax.

Avoid alcohol while taking kava.

Do not take if you have liver or kidney disease. 

Gingko biloba

Do not take if you have hypertension, diabetes, or are prone to seizures.