In order to understand why depression happens, it's necessary to understand a little about how the brain works. Neurotransmitters are natural substances that transmit messages between nerve cells in the brain. Some neurotransmitters, especially serotonin and norepinephrine, play an important role in regulating our moods. The new style antidepressants like Prozac attempt to regulate serotonin. The problem is that they also interfere with a number of other bodily functions, including appetite and sexual potency and may even dangerously lower serotonin, increasing violent tendencies.
The body can make these substances from foods in our diet. This means it's possible to raise levels of neurotransmitters that are too low simply by increasing our intake of the foods from which neurotransmitters are made.Tryptophan, an essential amino acid, is what serotonin is mainly derived from. When the diets of a number of countries are compared, those with a low-tryptophan intake were associated with a high rate of suicide. Studies have also shown that people suffering from severe depression have low levels of tryptophan, which improves as they do, and that depressed people put on a low-tryptophan diet get worse (Psycho Med, 1978; 8: 49-58; Arch Gen Psych, 1990; 47: 411-8). Since amino acids are components of protein, you can increase your levels of tryptophan through diet. However, since it's the least abundant amino acid in foods and also has to compete with so many others to enter the brain, it's best to use nutritional supplements. Studies that have been done so far show that tryptophan is as effective as antidepressants, without the horrendous side effects (Wurtman & Wurtman,
Nutrition and the Brain, Vol 7, Raven Press, NY, 1986). It's best to start with 25 mg taken with food and increase over 10-14 days to 75 mg three times daily. Tryptophan was given a bad press several years ago by the FDA and other medical authorities when it caused several deaths. However, it was recently exonerated when the problem was found to lie with contamination at the processing plant.
Before its conversion to serotonin, tryptophan must first be converted into 5-hydroxytryptophan (5-HTP). 5-HTP also has antidepressant properties roughly equivalent to antidepressant medications, and since it is a step closer to serotonin, not surprisingly, it appears to be even more effective than tryptophan. However, it can cause nausea and diarrhea, so it should be taken with meals to minimize irritation to the gut lining.
The other important neurotransmitter, in terms of your emotional equilibrium, is norepinephrine, which is derived from L-phenylalanine, another essential amino acid found in protein. This is also converted into phenylethylamine (PEA), a stimulant found in chocolate, in a reaction requiring vitamin B6. Although there hasn't been much research, in one study, a group of people with major depression were found to have low levels of a breakdown product of PEA. As soon as they began supplementing with L-phenylalanine and B6, their moods improved (J Clin Psych, 1986; 47 (2): 66-70).
Tyrosine, another amino acid, is yet another step closer in the chain to norepinephrine, and some small scientific studies suggest that taking supplements of it may be effective for some depressions (Adv Biol Psychiatry, 1983; 10: 148-59).
L-phenylalanine carries a number of side effects, including mild headaches, increased anxiety and insomnia, along with mild nausea and constipation.