Attention! Calling all neurotransmitters!

Inattention, trouble focusing, impulsivity, hyperactivity…  All children have trouble with these at some times, but for the 5-10% of school-age children with attention-deficit hyperactivity disorder (ADHD), these issues are a constant daily struggle.

ADHD is correlated with underlying biochemical imbalances

For many children, ADHD is correlated with an underlying biochemical imbalance. Photo credit: Corbis

Children with ADHD have been shown to have abnormalities in urinary excretion of the neurotransmitters β-phenylethylamine (PEA) and the catecholamines (epinephrine, norepinephrine, and dopamine).  Decreased PEA levels have been associated with inattentiveness, and research demonstrates that urinary PEA levels are significantly lower in ADHD patients.  Both decreased and increased levels of epinephrine and increased levels of a norepinephrine metabolite have also been observed in individuals with comorbid anxiety and ADHD.  This suggests that sympathetic adrenal function may be altered in subjects with ADHD.  Clinically, PEA, epinephrine, and norepinephrine affect attention, memory, focus, and energy.  Imbalances in any of these neurotransmitters correlate with the symptoms of inattention, focus issues, and hyperactivity commonly seen with ADHD.

Urinary neurotransmitter testing can help monitor ADHD treatment

Neurotransmitter testing can be a useful tool for monitoring ADHD treatment.  A study in 2002 by Kusaga et al found that responders to methylphenidate, a stimulant that inhibits the reuptake of norepinephrine and dopamine, had significantly increased urinary PEA levels.  Non-responders, however, did not demonstrate a significant change.  Methylphenidate increases urinary epinephrine and norepinephrine levels as well.  This example illustrates how changes in biomarkers can provide insight into the response of an individual patient to a particular intervention.

ADHD is a disorder that affects a significant number of children.  Urinary neurotransmitter testing can be beneficial in identifying the underlying biochemical imbalances present in children with ADHD.  Neurotransmitter testing can also be used to help monitor and adjust ADHD treatment regiments to suit a patient’s individual biochemistry; thus increasing treatment efficacy and improving clinical outcomes.

References:

Anderson, GM, et al. (2000). Adrenomedullary function during cognitive testing in attention-deficit/hyperactivity disorder. J Am Acad Child Adolesc Psychiatry, 39: 635-43.

Baker, GB, et al. (1991). Phenylethylaminergic mechanisms in attention-deficit disorder. Biol Psychiatry, 29: 15-22.

Berry, MD. (2004). Mammalian central nervous system trace amines. Pharmacologic amphetamines, physiologic neuromodulators. J Neurochem, 90: 257-71.

Elia, J, et al. (1990). Stimulant drug treatment of hyperactivity: biochemical correlates. Clin Pharmacol Ther, 48: 57-66.

Hanna, GL, et al. (1996). Urinary catecholamine excretion and behavioral differences in ADHD and normal boys. J Child Adolesc Psychopharmacol, 6: 63-73.

Kusaga, A, et al. (2002). Increased urine phenylethylamine after methylphenidate treatment in children with ADHD. Ann Neurol, 52: 372-4.

Pliszka, SR, et al. (1994). Urinary catecholamines in attention-deficit hyperactivity disorder with and without comorbid anxiety. J Am Acad Child Adolesc Psychiatry, 33: 1165-73.

Zametkin, AJ, et al. (1985). Stimulants, urinary catecholamines, and indoleamines in hyperactivity. A comparison of methylphenidate and dextroamphetamine. Arch Gen Psychiatry, 42: 215-5.