There are many plausible theories that explain the pathogenesis of ADHD in children and adolescents. The main theories thought to contribute the most to the development of ADHD are Neroanatomy, Neurophysiology, Neurochemistry, Genetic, Psychoneuroendocrine, Neurodevelopmental, and Neuroplasticity theories. However, there is one theory that stands out from the others. Neurochemistry theory, in my opinion, is the theory that best explains the etiology of ADHD. A majority of the literature also points to Neurochemistry theory as the main cause of ADHD. In addition, all of the other theories lead back to changes in the brain’s chemistry. Environmental factors, genetics, hormones, and bodily injuries all have been shown to cause direct or…show more content… Many patients’ symptoms improve when treated with medication. Currently, there are several medications that have been shown to correct neurotransmitter imbalances in the brain. In patients with ADHD, studies indicate that dopamine may be cleared too quickly from the synapse, which is indicative of increased dopamine transporter density (Krull, 2015). Stimulants, such as amphetamines and methylphenidate, are used as first-line medications to treat ADHD (Cortese, 2012). Both of these stimulants prevent the reuptake of norepinephrine and dopamine into the presynaptic neuron. Amphetamines promote norepinephrine and dopamine release into the extracellular area. Atomoxetine, a selective norepinephrine reuptake inhibitor (SNRI), works by indirectly increasing norepinephrine and dopamine concentrations in the prefrontal cortex area of the brain and also has some effect on the serotinergic system. Selective serotonin and norepinephrine reuptake inhibitors (SNRI), such as Venlafaxine and Duloxetine, have shown to help improve attention and decrease hyperactivity in human trials (Banerjee & Nandagopal, 2015). Tricyclic antidepressants (TCA) and selective serotonin reuptake inhibitors (SSRI), both of which act to prevent the reuptake of serotonin, are also used to treat ADHD. The serotonin deficiency hypothesis was raised after improvements in ADHD symptoms were shown in patients given medications that work on the serotinergic system. These findings further contribute to the plausibility of Neurochemistry theory as a causative factor in the development of ADHD (Cortese,
