Depression is a common emotional illness that varies widely in its intensity. Many of the natural treatments described in this section have been evaluated in people with major depression of mild to moderate intensity. This apparently contradictory language indicates a level of clinical depression that is significantly more intense than simply feeling "blue," but not as disabling as major depression of severe intensity, which usually requires hospitalization.

Typical symptoms of major depression of mild to moderate severity include depressed mood, lack of energy, sleep problems, anxiety, appetite disturbance, difficulty concentrating, and poor stress tolerance. Irritability can also be a sign of depression.

More severe depression includes markedly depressed mood complicated by symptoms such as slowed speech, slowed (or agitated) responses, markedly impaired memory and concentration, excessive (or diminished) sleep, significant weight loss (or weight gain), intense feelings of worthlessness and guilt, recurrent thoughts of suicide, and lack of interest in pleasurable activities. This form of clinical depression is a dangerous and excruciating illness. The emotional structure of the brain has frozen into a pattern of misery that cannot be altered by willpower, a change of scenery, or the most earnest efforts of friends. In a sense, the brain has locked up like a crashed computer.

One of the earliest successful treatments for major depression was shock therapy. This technique is in some ways analogous to rebooting a computer, and in cases of major depression, its effects were revolutionary. For the first time, a reliable way was available to bring people out of the depths of severe major depression.

However, shock treatment was overused at first and became unpopular as a result. The accidental discovery of antidepressant drugs provided a route with fewer interventions. The original antidepressants, known as MAO inhibitors, could bring people out from the depths of major depression as successfully as shock treatment. However, MAO inhibitors can cause serious and even fatal side effects. No one would ever think of using MAO inhibitors to treat mild to moderate depression.

Subsequently, antidepressants with progressively fewer side effects came on the market, but most of them still caused significant fatigue. Since fatigue is one of the most characteristic symptoms of mild to moderate depression, such medications were seldom found useful for anything other than severe depression. With the appearance of the selective serotonin reuptake inhibitor (SSRI) class of antidepressants, however, suddenly there was a practical option for depression that was less than catastrophic. Practically overnight, enormous numbers of people began taking Prozac and similar drugs for mild to moderate depression, as well as for the related, but more mild condition, known as dysthymia.

The big advantage of the SSRIs is that they usually don't cause severe fatigue. Many people find them to be entirely side effect-free. However, side effects are not uncommon and include sexual disturbances (such as impotence in men and the loss of the ability to experience an orgasm in women), insomnia, and nervousness. The antidepressant drug Wellbutrin is an option for people who have sexual side effects from SSRIs.

Alternative medicine offers numerous options for treating depression, but only one has strong scientific evidence behind it: the herb St. John's wort.

What Is the Scientific Evidence for St. John's Wort?

Numerous double-blind, placebo-controlled studies have examined the effectiveness of St. John's wort for the treatment of mild to moderate major depression, and most have found the herb more effective than placebo.1-6,123,135,155In addition, at least 8 studies have found that St. John's wort is at least as effective as standard antidepressants, including fluoxetine (Prozac), sertraline (Zoloft), citalopram (Celexa), and paroxetine (Paxil).7-9,124,125,136,137,148,192A 2008 detailed review of 29 randomized, placebo controlled trials found that St. Johns wort was consistently more effective than placebo and equally effective to standard antidepressants.180The total number of patients in these trials runs into the several thousands and compares favorably to the evidence-base for approved drugs. St. John’s wort has also shown a bit of promise for severe major depression, but the evidence is quite limited.137, 158

Note: St. John's wort alone should never be relied on for the treatment of severe depression.

Much has been made of two double-blind, placebo-controlled trials performed in the United States that failed to find St. John’s wort more effective than placebo for mild to moderate depression 5,123However, two studies cannot overturn a body of positive research. Approximately 35% of double-blind studies involving pharmaceutical antidepressants have also failed to find the active agent significantly more effective than placebo.123 As if to illustrate this, in the more recent of the two trials in which St. John’s wort failed to prove effective, the drug sertraline (Zoloft) also failed to prove effective. The reason for these negative outcomes is not that Zoloft (or Prozac, or any other drug) does not work. Rather, statistical effects can easily hide the benefits of a drug, especially in a condition like depression where there is as a high placebo effect and no truly precise method for measuring symptoms.

St. John's wort seldom causes immediate side effects. However, it interacts adversely with a large number of critical medications and may present other safety issues as well. For more information, see the full St. John's Wort article.