National Institute of Health Essay Example | Topics and Well Written Essays - 500 words

National Institute of Health - Essay Example And they are more inconsistent, affected by momentary events and dominated by objects in their immediate environment". However, when every function of the child is predominated by such behaviour then it is time to take cognizance. (Barkley, Russell. A, 1998). This disorder was first described by Heinrich Hoffman in 1845. A child with this affliction will either be hyperactive or will seem to be always lost in a brown study. The main causes for this disease are supposed to be neurobiological and genetic. A possible correlation between the use of alcohol and nicotine during pregnancy has been established by various studies. (Stock, Margaret, n.d). The hormone epinephrine (also known as adrenaline), is released during stressful situations producing an increased heart rate and increased blood flow to the muscles. Stimulants act similarly by increasing the levels of the neurotransmitters dopamine and norepinephrine in the brain. In addition they also act on the limbic system that reward behaviours like sexual intercourse, eating and drinking or in other words actions that are beneficial to the continuation of the species. These are normally accompanied by positive sensations due to increased levels of dopamine in the limbic system. Stimulants mimic this activity but at a much more enhanced level producing euphoric sensations by directly increasing dopamine level