Chapter 5 of Lilienfeld includes a section about amphetamines. I have ADHD and know that one of the forms of treatments is medications that act as stimulants, so this section drew my attention.
Firstly, ADHD is formally called attention deficit hyperactive disorder. It is mainly characterized by inattention, hyperactivity, and impulsivity. A lack of dopamine and norepinephrine in the brain is believed to cause these symptoms of ADHD. These chemicals serve in focus, memory, and impulse control.
Next, Amphetamines are a class of stimulant (a drug that increases the activity in the CNS). Amphetamines increase the amount of dopamine and norepinephrine that is released. This means that more neurotransmitters are released from storage sites into the synapses.
For a person without ADHD, this results in a "rush".
It is rumored that militaries have used amphetamines to increase energy levels and motivation in troops. An example of the controversy surrounding this long time rumor is: in 2003 there was an incident where two American pilots bombed Canadian forces in Afghanistan. The pilots had been using amphetamines issued to them, and this factor sparked a mad debate.
For a person with ADHD, this results in increased focus, memory, and impulse control. This can be explained by the increased activity and communication in the parts of the brain that involve the two chemicals. In studies, the parts of the brain involved in executive functions, including the prefrontal cortex, specific subcortical regions, and the cerebellum, were shown to be more active with the use of amphetamines.
One quote I have liked since I was first learning about treatments for my ADHD is: "Taking stimulants is not like taking doses of an antibiotic to wipe out an infections; it is more like wearing eyeglasses that correct one's vision while the glasses are being worn, but do nothing to fix one's impaired eyes." This means that there is no cure for ADHD, but the symptoms can be alleviated. This factor is interesting because it allows us to look at the duration of the effects of certain chemicals/hormones/etc. in the brain.