Amphetamines
The amphetamines include legitimate pharmaceutical preparations as well as illicitly produced substances. Amphetamines have been used medically as bronchodilators for asthma, appetite depressants for weight loss, in treatment of attention deficit disorder in children and of narcolepsy, and as a supplement in the treatment of some forms of resistant depression. During World War II and the Vietnam war, amphetamines were made available to troops to help counteract fatigue and improve concentration.

During the 1960s and 1970s, the illicit use of amphetamines became widespread. A large proportion of the drugs came from the diversion of legitimately produced pharmaceutical preparations. As a result of increased regulatory efforts, it is less common now to find drugs such as Dexedrine or Benzedrine on the streets. Instead, the supply of crystal methamphetamine produced in illegal labs has grown. “Cooking” crystal meth is relatively easy and quite lucrative, although it is extremely dangerous. The chemicals used to create the drug are toxic and highly explosive. Crystal meth addiction tends to cluster in certain parts of the country, such as the South and the Southwest, close to the illicit labs. It’s also frequently abused by long-haul truckers. In some cases, crack cocaine addicts have turned to crystal meth as a substitute because of the lower cost and longer high.

Amphetamines exert their effect on the brain in a twofold fashion. They attach to and directly stimulate the cells that oduce excitation of certain areas of the brain. They also cause these cells to secrete neurotransmitters like norepinephine and dopamine, which also contribute to the stimulating and euphoric effects. The main problem with the amphetamines is that, in overriding the brain’s normal regulatory mechanisms, they cause profound depletion of the brain’s normal chemicals, just as cocaine does. Even months after cessation of use, lab animals demonstrate lower than normal levels of important neurotransmitters like norepinephrine, dopamine, and serotonin. It is thought that in some cases of long-term, heavy use, these chemicals never return to normal levels.

Long-term, heavy use of amphetamines leads to a psychosis that is clinically indistinguishable from paranoid schizophrenia. “Speed freaks” become intensely paranoid, and may experience hallucinations. Amphetamines also trigger seriously aggressive behavior, especially if the user feels threatened.

Physical effects of the stimulant properties of amphetamines can lead to major physical complications such as heart damage, strokes, and life-threatening fevers.

Amphetamines are similar to other stimulant drugs in how they produce addiction. There is a powerful conditioning effect. The brain learns to associate a pleasurable sensation with all kinds of cues connected to the use of the drug. During the early period of abstinence, as with cocaine, the addict has to deal with powerful cravings that are a result of this learning process.