The problems I see with urinary neurotransmitter testing are as follows:
1. Urinary neurotransmitter metabolites don't necessarily correlate with the levels of neurotransmitters in the brain. Since there are tons of neurotransmitters elsewhere in the body and all of the bodily fluids eventually get filtered into the urine by the kidneys, there is no way to know where these metabolites are coming from. For example, the majority of serotinin and dopamine are found in the gastrointestinal tract, not the brain! Acetylcholine is found at each neuromuscular junction in your body as well as the hippocampus in the brain.
2. Many neurotransmitters are recycled (we in the biz call this "re-uptake") on-site, so their metabolites generally don't get excreted in the blood or urine. Serotonin is one such neurotransmitter, while Acetylcholine is broken down after each use.
3. The activity of neurotransmitters is dependent on numerous things- not just the amount of neurotransmitter available. Things like anemia, high blood sugar, inflammation, autoimmune disease, and poor nutrition are much more likely to affect the brain before a blatant neurotransmitter deficiency problem sets in. For that matter, any of those things can cause a neurotransmitter imbalance and must be addressed in treatment.
4. Neurotransmitters do different things in different parts of the brain and body. For example, Dopamine can be excitatory or inhibitory, depending on which receptor is activated and which pathway is stimulated. GABA is found in numerous places in the brain including the frontal lobe, basal ganglia, and cerebellum and is involved in a variety of different pathways. GABA is always inhibitory, but can inhibit excitatory or inhibitory pathways, which may make its' overall effect either excitatory or inhibitory.
All that being said, there is a time and a place for the use of neurotransmitter-specific supplements and treatments... I just think that testing for urinary neurotransmitters is a waste of time and money. Below is my general approach when assessing neurotransmitter function.
1. Patients in my office fill out the Neurotransmitter Assessment Form prior to their first appointment. This form looks at clusters of symptoms that are indicative of neurotransmitter imbalances.
2. I address Overall Brain Health first and foremost in my office. I know this sounds like a really wishy-washy topic, but it's surprisingly important. Neurons (brain cells) need three basic things to survive: Oxygen, fuel (glucose, ketones), and stimulation. This is why ruling out things like anemia, high blood pressure, excessively low blood pressure, blood sugar problems, and hemisphericity needs to be part of the work up for anyone suspecting neurotransmitter imbalance. Many hormones have the ability to globally affect brain function, so thyroid problems and hormonal imbalance should be checked for, too. Even inflammation, digestive problems, food sensitivities, and gut bacteria imbalances can have a tremendous impact on the brain and it's ability to function.
3. Last but not least, if the topics addressed in step two have not resolved the patient's symptoms and they still present with signs of neurotransmitter imbalance I may choose to supplement accordingly. Generally I use combination supplements that include precursor amino acids, vitamins and co-factors needed to make neurotransmitters, and herbs that boost that activity of different receptors.
If you or somebody you know is interested in working with a functional medicine doctor please call my office at (919) 238-4094 and see if we are the right fit for you. Infinity Holistic Healthcare is located in Chapel Hill, North Carolina, part of the Raleigh-Durham "triangle" area.