http://articles.mercola.com/sites/articles/archive/2008/01/02/tryptophan-and-depression.aspxTryptophan is an amino acid (protein building block) that the body converts in two chemical steps to serotonin. Serotonin is a neurotransmitter that is frequently unbalanced in depressive individuals. Conventional antidepressants work to increase neurotransmitterenCommunityServer 2008.5 SP1 (Build: 31106.3070)