Central nervous system stimulant
The brain, spinal column, and their internal network of millions of nerve cells make up the central nervous system (CNS) of the human body. This system controls the functions of internal organs, such as the heart and stomach, without a person's conscious awareness, and it also controls complex reactions that are within conscious awareness. For example, a person may sense danger, look around him and see a predator, and then run away. This complex reaction to stimuli is achieved through a complex series of actions and reactions that take place through the central nervous system.
A central nervous system stimulant is any drug or substance that speeds up this system. These can include commonly available substances such as caffeine, nicotine and cocoa, and very strong illegal drugs such as methamphetamine.
Prescription stimulants of the nervous system are commonly used to treat sleeping disorders, obesity, and attention deficit disorder/hyperactivity. They are sometimes added to enhance pain relievers. Methylphenidate and dextroamphetamine are stimulants of the central nervous system, and they are the main ingredients in trademarked drugs for attention deficit disorder, such as Ritalin, Concerta, Metadate, and Adderall. These are among the most widely prescribed drugs in use.
Another stimulant of the nervous system is cocaine, which has some medical uses as a local anesthetic, but is widely abused illegally. The same is true for methamphetamine, the second most abused drug in the world. Certain hallucinogenic drugs and alcohol can function both as stimulants and depressants of the central nervous system.
These stimulants are addictive in that they can make people feel more alert, self-confident, intelligent, energetic, and happy. However, when these effects wear off, the user may "crash" and feel more depressed than if he had not taken the drug. Side effects are increased heart rate, higher blood pressure, faster breathing, nervousness, aggressiveness, irritability, insomnia, loss of appetite, headaches, moodiness, and dizziness. In the long term, stimulants can cause permanent damage to the human body. Once a person becomes addicted to them, he will have to unpleasant undergo withdrawal symptoms such as depression, sleep problems, and moodiness.