About Psychoactive Drugs
A psychoactive drug, psychopharmaceutical or psychotropic is a chemical substance that crosses the blood-brain barrier and acts primarily upon the central nervous system where it alters brain function, resulting in changes in perception, mood, consciousness, cognition, and behavior. These drugs may be used recreationally, to purposefully alter one's consciousness, as entheogens for ritual or spiritual purposes, as a tool for studying or augmenting the mind, or therapeutically as medication.
Because psychoactive substances bring about subjective changes in consciousness and mood that the user may find pleasant or advantageous , many psychoactive substances are abused, that is, used excessively, despite risks or negative consequences. With sustained use of some substances, physical dependence may develop, making the cycle of abuse even more difficult to interrupt. Drug rehabilitation aims to break this cycle of dependency, through a combination of psychotherapy, support groups and even other psychoactive substances.
In part because of this potential for abuse and dependency, the ethics of drug use are the subject of a continuing philosophical debate. Many governments worldwide have placed restrictions on drug production and sales in an attempt to decrease drug abuse. Ethical concerns have also been raised about over-use of these drugs clinically, and about their marketing by manufacturers.
Drug use is a practice that dates to prehistoric times. There is archaeological evidence of the use of psychoactive substances dating back at least 10,000 years, and historical evidence of cultural use over the past 5,000 years. While medicinal use seems to have played a very large role, it has been suggested that the urge to alter one's consciousness is as primary as the drive to satiate thirst, hunger or sexual desire. The long history of drug use and even children's desire for spinning, swinging, or sliding indicates that the drive to alter one's state of mind is universal.
This relationship is not limited to humans. A number of animals consume different psychoactive plants, animals, berries and even fermented fruit, becoming intoxicated, such as cats after consuming catnip. Traditional legends of sacred plants often contain references to animals that introduced humankind to their use. Biology suggests an evolutionary connection between psychoactive plants and animals, as to why these chemicals and their receptors exist within the nervous system.
During the 20th century, many governments across the world initially responded to the use of recreational drugs by banning them and making their use, supply or trade a criminal offense. A notable example of this is the Prohibition era in the United States, where alcohol was made illegal for 13 years. However, many governments have concluded that illicit drug use cannot be sufficiently stopped through criminalization. In some countries, there has been a move toward harm reduction by health services, where the use of illicit drugs is neither condoned nor promoted, but services and support are provided to ensure users have adequate factual information readily available, and that the negative effects of their use be minimized.
Psychoactive substances are used by humans for a number of different purposes. These uses vary widely between cultures. Some substances may have controlled or illegal uses while others may have shamanic purposes, and still others are used medicinally. Other examples would be social drinking or sleep aids. Caffeine is the world's most widely consumed psychoactive substance, but unlike many others, it is legal and unregulated in nearly all jurisdictions. In North America, 90% of adults consume caffeine daily.
Psychoactive drugs are divided into 3 groups:
General anesthetics are a class of psychoactive drug used on patients to block pain and other sensations. Most anesthetics induce unconsciousness, which allows patients to undergo medical procedures like surgery without physical pain or emotional trauma. To induce unconsciousness, anesthetics affect the GABA and NMDA systems. For example, halothane is a GABA agonist, and ketamine is an NMDA receptor antagonist.
Psychoactive drugs are often prescribed to manage pain. As the subjective experience of pain is regulated by endogenous opioid peptides, pain can be managed using psychoactives that operate on this neurotransmitter system as opioid receptor agonists. This class of drugs can be highly addictive, and includes opiate narcotics, like morphine and codeine.NSAIDs, such as aspirin and ibuprofen, are a second class of analgesics. They reduce eicosanoid-mediated inflammation by inhibiting the enzyme cyclooxygenase.