A problem with ADHD is that the levels of the chemical messengers of the brain are disturbed. While stimulant medications have been the treatment of choice to help counteract this imbalance, according to Gene-Jack Wang and associates in 2010 in the "Journal of Nuclear Medicine," amino acids have been shown to be effective. However, the advice of a qualified professional should always be consulted regarding the treatment of ADHD.
Reduced heart rate has often been associated with ADHD and aggressive behavior according to Florian Daniel Zepf and colleagues in 2009 in the "Journal of Neurotransmission." Therefore, reduced heart rate is considered to be a valid scientific indicator of ADHD, the authors explain. Heart rate is known to be affected by neurotransmitters, therefore, they have been a target for investigation for ADHD. Since amino acids can behave as and shape the formation of neurotransmitters, they are considered to be involved as well, according to Zepf and colleagues.
Rapid depletion of the amino acid tryptophan results in reduced neurotransmission of the chemical messenger serotonin, as explained by Zepf and colleagues. Heart rate is reduced when this occurs, as the researchers note. Also, the uptake of the neurotransmitters dopamine and serotonin is interrupted, the creation of the two is altered, and the breaking-down process is disturbed, according to Robert Oades and colleagues in 2008 in "Progress in Brain Research."
Tryptophan depleting drugs were found to reduce levels of the neurotransmitter serotonin, reduce heart rate and increase ADHD behavior in a group of boys in the study conducted by Zepf and colleagues. Therefore, tryptophan affects the function of the neurotransmitter serotonin, the authors explain. Also, significant improvements in attention and visual and auditory responses were found when a supplement mix containing amino acids were given to people with ADHD in a study conducted by Luke Curtis, M.D., C.I.H., M.S. and colleagues, which was published in 2008 in "The Journal of Alternative Medicine." Tyrosine is an amino acid used in neurotransmitter synthesis and functioning related to dopamine, according to Bryan Kolb and Ian Whishaw in the 2003 book "Fundamentals of Human Neuropsychology." Tyrosine comes from food and is small enough to make it past digestion to be packaged into the axon terminal, which is essential for an amino acid to be effective.
Given the complex nature of ADHD, multiple treatment modalities are likely the best way to treat it, according to Curtis and colleagues. ADHD is explained by prenatal, social, developmental, nutritional and environmental factors and should be treated accordingly, the researchers explain. A thorough approach to treating ADHD should encompass nutritional, pharmacological, environmental and psychosocial interventions, as stated by the research team.
Although human and rat physiologies differ, rat studies shed some light on the idea that ADHD has environmental causes. ADHD behavior type rats showed more excitatory amino acids present when they were not handled much by the researchers prior to reaching puberty, compared to those that were left undisturbed, according to a study conducted by L. Ruocco and colleagues published in March 2009 in "Behavioural Brain Research." So, being handled physically was able to reduce the amount of excitatory amino acids that have repeatedly been linked to ADHD behaviors.