Shedding light on the unknown molecular mechanism of ADHD

By Dr Georgios Efthimiou, molecular biologist – geneticist PhD

The human is a complex and mysterious organ. Despite the thousand recent studies by neurobiologists there is still much we don’t know about it. However, new research has led scientists to certain biochemical pathways and developmental genes that are suspects of participation in ADHD pathogenesis.

Understanding the exact mechanism of this disorder is not a luxury. It is essential for timely diagnosing and effectively treating ADHD by doctors and expert psychologists.

1. Neurotransmitter networks

Neurotransmitters are chemical substances that deliver certain messages from neuron to neuron. Are as of the brain that are control movement or sense of motive and reward are located at the frontal lobe of the brain and the corpus callorum at the center of the organ. These areas are controlled by the neurotransmitters dopamine and norepinephrine via specific circuits that are still being mapped, similarly with the genes that encode for these neurotransmitters¹.

2. Developmental genes

By using modern imaging methods,  it was found that people with ADHD often have less dense neural mass at the left part of frontal lobe and thinner walls at the rear part of parietal lobe (at the back of the head). This indicates that the development or maturation of these are as was incomplete, urging the scientists to also focus on the hundreds of developmental genes that define brain’s growth¹.

3. Environmental effects

At least three environmental factors are known to cause or worsen ADHD symptoms:

• Smoking, alcoholoveruse, ordrugusebythemotherduringpregnancy^2,3
• Toxic agents in water or air (lead, pesticides, etc.)⁴
• Diet lacking certain trace elements and vitamins (magnesium, iron, Vitamins D and E)⁵

By deciphering these complex neurochemical and other secrets that are responsible for the development of ADHD, scientists will soon have new weaponry in their hands for improving the life of children with ADHD.

 

SOURCES:

1. Malenka RC, Nestler EJ, Hyman SE (2009). “Chapters 10 and 13”. In Sydor A, Brown RY. Molecular Neuropharmacology: A Foundation for Clinical Neuroscience (2nd ed.). New York: McGraw-Hill Medical. pp. 266, 318–323.
2. Burger PH, Goecke TW, Fasching PA, Moll G, Heinrich H, Beckmann MW, Kornhuber J (September 2011). “[How does maternal alcohol consumption during pregnancy affect the development of attention deficit/hyperactivity syndrome in the child]”. For tschrNeurolPsychiatr (in German) 79 (9): 500–506.
3. Abbott LC, Winzer-Serhan UH (April 2012). “Smoking during pregnancy: lessons learned from epidemiological studies and experimental studies using animal models”. Crit. Rev. Toxicol. 42 (4): 279–303.
4. Eubig PA, Aguiar A, Schantz SL (December 2010). “Lead and PCBs as risk factors for attention deficit/hyperactivity disorder”. Environ. HealthPerspect. 118 (12): 1654–1667.
5. Efthimiou G. (2015). The role of nutrition in the battle against ADHD