Neurotransmitters excreted in the urine as biomarkers of nervous system activity: Validity and clinical applicability

• Published in: Neuroscience and biobehavioral reviews 2011-01, Vol.35 (3), p.635-644
• Main Authors: Marc, David T., Ailts, Joseph W., Campeau, Danielle C. Ailts, Bull, Michael J., Olson, Kelly L.
• Format: Article
• Language: English
• Subjects: ADHD; Adult and adolescent clinical studies; Animals; Attention Deficit Disorder with Hyperactivity - diagnosis; Attention Deficit Disorder with Hyperactivity - urine; Behavioral psychophysiology; Biological and medical sciences; Biological Transport - physiology; Biomarker; Biomarkers - urine; Blood-Brain Barrier - metabolism; Depression; Depressive Disorder - diagnosis; Depressive Disorder - urine; Fundamental and applied biological sciences. Psychology; Humans; Inflammation; Inflammation - diagnosis; Inflammation - urine; Medical sciences; Mood disorders; Nervous system; Nervous System - metabolism; Neurotransmitter; Neurotransmitter Agents - urine; Psychiatric; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychopathology. Psychiatry; Reproducibility of Results; Urinary
• ISSN: 0149-7634; 1873-7528
• DOI: 10.1016/j.neubiorev.2010.07.007

▶ Neurotransmitters excreted in urine are biomarkers to assess the nervous system. ▶ Improved technology has increased the sensitivity, specificity, and lowered cost. ▶ The mechanism of neurotransmitters transport from the brain to the blood. ▶ The mechanism of neurotransmitters transport from the blood into the urine. ▶ Urinary neurotransmitter testing for depression, ADHD, and inflammation. Strategies for managing the nervous system are numerous while methods of evaluating the nervous system are limited. Given the physiological importance of neurotransmitters as signaling molecules in the nervous system, the measurement of neurotransmitters has significant potential as a clinical tool. Of all the biological fluids that can be utilized, urinary neurotransmitter testing, due to its stability, sensitivity, and non-invasiveness, is the desired method to analyze nervous system function. Increasing use of this technology in a clinical setting demands a review of its feasibility, utility, and clinical value. We review the current body of literature pertaining to the mechanism of neurotransmitter transport across the blood–brain barrier as well as neurotransmitter filtration and excretion by the kidneys. In addition, this review summarizes the historical use of urinary neurotransmitter assessment to diagnose pheochromocytoma. Early research also correlated urinary assessment of neurotransmitters to various clinical symptoms and treatments of which we present research only for depression, ADHD, and inflammation because of the abundant amount of research in these areas. Finally, we review the limitations and challenges of urinary neurotransmitter testing. Taken together, evidence suggests that neurotransmitters excreted in the urine may have a place in clinical practice as a biomarker of nervous system function to effectively assess disturbances and monitor treatment efficacy.