Amino acid analysis can be an important part of any thorough nutritional and metabolic analysis, especially in cases of chronic conditions that have been difficult to diagnose or have failed to respond to treatment.
Many laboratories are beginning to offer profile testing of up to 40 amino acids and related products, providing information on a variety of metabolic and nutritional disorders.
Disorders that can be discovered through an Amino Acid Profile include: protein inadequacy, gastrointestinal insufficiencies, inflammatory responses, vitamin and mineral dysfunctions, detoxification impairments, cardiovascular disease, ammonia toxicity, food and chemical sensitivities, depression, neurological dysfunction and inborn errors of metabolism.
Amino acid profiles done on blood can reveal imbalances seen in a variety of disorders including depression. Low tyrosine or phenylalanine levels can result in abnormal levels of mood-regulating chemicals in the brain, such as dopamine and catecholamines. Low tyrosine levels can also create subnormal levels of thyroid hormone – a well-known cause of depression.
Methionine is the precursor of SAMe which is needed for proper functioning of catecholamines and may be low in patients with depression.
Tryptophan is the body's source material for producing the hormones serotonin and melatonin, which also influence sleep patterns and mood. Depletion of tryptophan can cause an increase in depressed mood states; lower tryptophan levels have been correlated with a higher depression score even in patients who were already under treatment with anti-depressant drugs. [Arch Gen Psychiatry 1990;47(5): pp.411-18]