Organic Acid Testing For Neurotransmitters
The following information may be helpful to understand treatment options for mental symptoms such as depression or anxiety. But please keep in mind that the first step in treatment should be a thorough history. It's best to talk to a qualified practitioner before deciding that a specific functional lab test is needed. Not everyone is necessarily going from organic testing.
Organic acid testing
Organic acids are metabolic wastes the body excretes through the urine. An organic acid test helps to uncover blocks in metabolism.
For example, lets say you want to assess need for folate (folic acid). The organic acid Formiminoglutamate (FIGLU) can be tested.
FIGLU is converted into glutamate by folate. Hi FIGLU in the urine indicates a functional need for more folate. There is a blood test for folate, but at times it comes back normal despite a functional need for more folate. In these cases the FIGLU marker serves as a functional assessment where the blood folate test does not. 
Some advantages to organic acid testing
- Organic acid tests shows if you have enough to meet your specific metabolic needs. Just counting up how much of any vitamin is in your blood doesn't do this.
- Not all vitamins are stored in the blood. For example vitamin B12 is stored in the liver. So how do we know that blood levels of B12 are the most accurate measurement?
- There are some metabolites for which there are no blood tests.
- Organic acid tests can reveal problems before they show up as deficiencies on other tests.
Organic acid tests for mental symptoms
Organic acid tests have numerous markers which may be helpful for people with mental symptoms.
B vitamin markers
Many B vitamins can be tested on an organic acid test. Two of the most important to consider with mental symptoms are vitamins B6 and B12.
B6 can be depleted by many medications (oral contraceptives, hypertension drugs) and exposure to common toxins such as pesticides. Symptoms of B6 deficiency include neurological problems such as poor balance, fatigue and mental/emotional instability. Vitamin B6 status can be tested with the organic acid xanthurenate. 
A vegetarian diet and poor digestive function are two of the most common causes of low B12 .B12 deficiency can present anemia, high homocysteine and neurological symptoms. Sometimes people are not anemic and have normal homocysteine, yet vitamin B12 deficiency is presenting only as neurological problems. Need for vitamin B12 need can be determined with methylmalonate.
Often people may have have a function need for vitamin B12,yest have normal blood serum levels. For this reason methylmalonate can be a more clinically relevant test.
Homovanillate (HVA) and vanilmandelate (VMA), are by-products of dopamine, norepinephrine and epinephrine metabolism.
These three neurotransmitters are important for mental and neurological function.
Low HVA indicates low levels of dopamine. This can indicate need for tyrosine and vitamins B6.
Low VMA indicates decreased adrenaline and nor-adrenaline production. Tyrosine, B6, or copper, may be helpful. Low VMA may also indicate adrenal exhaustion.
symptoms of low HVA and VMA include: depression, sleep disturbances, inability to deal with stress and fatigue.
In conventional medicine profound elevations of VMA is used to diagnose neuroblastic tumors. Functionally speaking, elevated VMA indicates stress or a metabolic problem causing too much production of catecholamines.
It may seem intuitive that people with anxiety and panic attacks have high levels of adrenaline and therefore increased VMA. In fact, the opposite is often true, anxiety is associated with low VMA and low catecholamines. 
Metabolism of serotonin can be measured through the metabolite it's broken down into, 5-hydroxyindoleacetate (5-HIAA). This represents total body metabolism of one serotonin pathway.
Low 5-HIAA indicates inadequate production of serotonin. Symptoms include: constipation, depression, fatigue, insomnia, attention deficit and behavioral disorders.
High 5-HIAA can be caused by SSRI medication, 5-HTP supplementation, increased release of serotonin from the central nervous system, digestive system or platelets. Very high 5-HIAA levels can ironically indicated a tryptophan deficiency, as this may cause an increased conversion of tryptophan to serotonin.
Elevated kyurenate and quinolinate indicate tryptophan is being used to produce inflammation instead of serotonin. High quinolinate levels in the brain can cause insomnia, irritability and nervousness. In this case the cause of inflammation needs to be treated. Simply giving the patient 5-htp and vitamins to make more serotonin is not going to work if those are just going to be converted into inflammatory cytokines. 
What other markers are on organic acid tests?
Organic acid tests can also be used to test detoxification pathways, metabolites of cellular energy function (to help determine need for supplements such as CoQ10) and there are even metabolites produces by bacteria in the G.I. system which can help show the cause of gastrointestinal symptoms.
However, interpretation of organic acid results take some skill, so it's best to have the guidance of someone familiar with the test. Interpretation should also take into account other factors which are not on the test, such as symptoms and medical history.
Ordering an Organic Acid Test
Organic acids tests are usually run as large panels of about 40 metabolites. These are available through specialty labs such as Genova Diagnostics. Lab tests are ordered through licensed practitioners, typically someone who works in natural health; Naturopathic Doctor, Chiropractor, Integrative Medical Doctor, etc.
 Lord, Richard S., J. Alexander. Bralley, and J. Alexander. Bralley. Laboratory Evaluations for Integrative and Functional Medicine. Duluth, GA: Metametrix Institute, 2008. 348-350. Print.
 Lord, Richard S., J. Alexander. Bralley, and J. Alexander. Bralley. Laboratory Evaluations for Integrative and Functional Medicine. Duluth, GA: Metametrix Institute, 2008. 343-344. Print.
 Lord, Richard S., J. Alexander. Bralley, and J. Alexander. Bralley. Laboratory Evaluations for Integrative and Functional Medicine. Duluth, GA: Metametrix Institute, 2008. 351-352. Print.
 Lord, Richard S., J. Alexander. Bralley, and J. Alexander. Bralley. Laboratory Evaluations for Integrative and Functional Medicine. Duluth, GA: Metametrix Institute, 2008. 353-354. Print.