Chronic Use of _____ Can Produce Lasting Damage to Serotonin-releasing Neurotransmitters.

Depressants

Depressants cause the body to relax by increasing the neurotransmitter GABA, which decreases neuronal excitability.

Learning Objectives

Compare the effects of different types of depressants on the brain

Key Takeaways

Key Points

• Depressants exercise not directly reduce arousal in the brain; they enhance the activity of a neurotransmitter that reduces arousal in the brain.
• The main types of depressants are alcohol, barbiturates, benzodiazepines, cannabinoids, and opioids.
• Examples of common depressants include hurting killers and social- feet medications, which take similar effects on the brain.

Key Terms

• ataxia: Lack of coordination while performing voluntary movements, which may announced to be clumsiness, inaccuracy, or instability.
• anxiolysis: The reduction of anxiety past means of sedation or hypnosis.

A depressant (also chosen a central depressant) is a chemic compound that manipulates neurotransmission levels, thereby reducing arousal or stimulation in various parts of the brain. Depressants are also occasionally referred to as "downers" because they lower the level of arousal in the encephalon when taken. Stimulants, or "uppers," which increment mental and/or physical part, are the functional opposites of depressants.

Effects of Depressants

Depressants are widely used throughout the world every bit prescription medicines and as illicit substances. Effects often include ataxia, anxiolysis, hurting relief, sedation or somnolence, and cognitive/memory impairment; in some instances, effects include euphoria, dissociation, musculus relaxation, lowered blood pressure or heart rate, respiratory depression, anticonvulsant effects, and fifty-fifty complete anesthesia or expiry. Calming effects of depressants may be beneficial to those suffering from anxiety, sleep disorders, or pain; nonetheless, the more extreme effects can exist dangerous and even life-threatening.

On the neural level, most depressants deed on the brain past affecting the neurotransmitter gamma-aminobutyric acid (GABA), which is responsible for regulating (specifically, decreasing) neuronal excitability throughout the nervous organisation.
Neurotransmitters are encephalon chemicals that facilitate communication betwixt brain cells. Depressants inhibit the next neuron from sending impulses by binding to receptor molecules. Although the dissimilar classes of depressants piece of work in unique ways, it is through their ability to increment GABA—and thereby inhibit encephalon activeness—that they produce a drowsy or calming effect.

Types of Depressants

Alcohol

Though initially a stimulant, booze ultimately depresses the brain, resulting in relaxation and dumb judgment.

Alcohol every bit a depressant: Alcohol depresses the brain, resulting in relaxation and impaired judgment.

Barbiturates

Barbiturates are effective as anxiolytics, hypnotics, and anticonvulsants, and also take an analgesic (painkiller) effect. However, they are commonly misused, physically addictive, and accept serious potential for overdose. In the late 1950s, it became clear that the social cost of barbiturates was beginning to outweigh the medical benefits, which sparked a serious search for a class of replacement drugs. Almost people still using barbiturates today practise and so to preclude seizures or for relief of migraine symptoms.

Barbiturates have been largely replaced by benzodiazepines, because the latter accept fewer side effects and less potential for lethal overdoses. Withal, barbiturates are nonetheless used every bit anti-convulsants (e.thousand., phenobarbital, an anti-seizure medication), as sedatives (e.one thousand., sodium thiopental), and analgesics for cluster headaches and migraines (due east.g., Fioricet).

Benzodiazepines

Benzodiazepines enhance the issue of the neurotransmitter gamma-aminobutyric acid (GABA) at the GABA receptor, resulting in allaying, hypnotic (sleep-inducing), anxiolytic (anti-anxiety), anticonvulsant, and muscle-relaxant properties. Amnesic-dissociative actions are as well seen in the applied pharmacology of high doses of many shorter-acting benzodiazepines. These properties make benzodiazepines useful in treating feet, indisposition, agitation, seizures, muscle spasms, alcohol withdrawal, and every bit a premedication for medical or dental procedures. Some of the most common benzodiazepines are anti-anxiety medications, such as clonazepam (Klonopin), alprazolam (Xanax), diazepam (Valium), and zolpidem (Ambien).

Cannabinoids

Although cannabis or marijuana is ofttimes considered either in its own unique category or as a balmy psychedelic, the drug—notably the chemical chemical compound cannabidiol that it contains—yet has many depressant furnishings such as muscle relaxation, sedation, decreased alertness, and tiredness. At that place are at least 85 different cannabinoids isolated from cannabis, the about common of which is THC, the active ingredient in marijuana. Cannabinoids can be administered by smoking, vaporizing, oral ingestion, transdermal patch, intravenous injection, sublingual absorption, or rectal suppository. Once in the body, virtually cannabinoids are metabolized in the liver.

Opioids

An opioid is whatsoever psychoactive chemical that resembles morphine or other opiates in its pharmacological effects. One of the oldest known drugs, opioids induce an analgesic (painkiller) effect by decreasing perception of pain, decreasing reaction to pain, and increasing pain tolerance. Known for their highly addictive quality, opioids piece of work by bounden to opioid receptors, which are found principally in the central and peripheral nervous arrangement and the alimentary canal. Opioids are among the world's oldest known drugs; therapeutic use of the opium poppy predates recorded history. The virtually common opioids in modernistic history are morphine, heroin, and codeine, which are known as incredibly constructive, albeit addictive, painkillers. Every bit opposed to these naturally occurring opioids that are derived directly from the resin of the poppy institute, synthetic opioids are synthesized chemically in the laboratory and are agents unremarkably used in hurting relief, treating drug dependence and anesthesia. Some examples include hydrocodone and oxycodone.

A Note on the Term "Narcotics"

The term "narcotic" originally referred medically to any psychoactive compound with sleep-inducing backdrop. In the United States, it has since become associated with opioids, usually morphine and heroin and their derivatives. The term is, today, imprecisely defined and typically has negative connotations. When used in a legal context in the United States, the term "narcotic drug" refers to a substance that is completely prohibited, or one, such as codeine or morphine, that is used in violation of governmental regulation. From a medical standpoint, it is no longer a useful term.

Stimulants

Stimulants induce temporary improvements in mental and/or concrete functions and are commonly used every bit prescription or recreational drugs.

Learning Objectives

Compare the furnishings of different types of stimulants on the brain

Primal Takeaways

Fundamental Points

• Stimulants increase the activity of the central nervous system, the sympathetic nervous system, or both.
• Well-nigh stimulants work by facilitating the activeness of sure neurotransmitters, such as dopamine or norepinephrine.
• Stimulants are often used medically to boost endurance, annul fatigue, promote weight loss, amend mood, or salve anxiety; they are also often used to treat conditions such as narcolepsy, ADHD, and sure forms of low.
• Examples of well-known stimulants include amphetamines, MDMA, NDRIs, cocaine, caffeine, and nicotine.

Primal Terms

• neurotransmitter: Any substance, such as acetylcholine or dopamine, responsible for sending nerve signals across a synapse between two neurons.
• dopamine: A neurotransmitter associated with movement, attention, learning, and the brain's pleasance and reward organization.
• narcolepsy: A disorder characterized by sudden, uncontrollable, and often cursory attacks of deep slumber, sometimes accompanied by paralysis and hallucinations.

Function of Stimulants

Stimulants are psychoactive drugs that induce temporary improvements in mental and/or physical functions. Occasionally referred to as "uppers," stimulants are the functional opposites of depressants, or "downers," which decrease mental and/or concrete office. Stimulants are widely used throughout the world equally prescription medicines and as illicit substances of recreational use or abuse.

Stimulants increase the activeness of the central nervous organization (the brain and spinal string), the sympathetic nervous system (function of the peripheral nervous system that controls the fight-or-flight response), or both. Common furnishings, which vary depending on the substance in question, may include enhanced alertness, sensation, wakefulness, endurance, productivity, and motivation. Effects tin can also include an increment in arousal, locomotion, heart charge per unit, and blood pressure, and the perception of diminished requirements for food and sleep. Some stimulants produce a sense of euphoria, specially those that exert influence on the key nervous system.

Neurological Mechanisms of Stimulants

Stimulants exert their furnishings through a number of different mechanisms. Some stimulants facilitate the activity of certain neurotransmitters, specifically norepinephrine and/or dopamine. Others block the action of sure receptors (such as the adenosine receptors) in a procedure known every bit receptor antagonism. Still others crusade action in other receptors (such as nicotinic acetylcholine) in a process known every bit receptor agonism.

Use and Abuse of Stimulants

Therapeutically, stimulants are used and/or prescribed for a multifariousness of reasons. They are used to increase or maintain alertness; to heave endurance or productivity; to counteract fatigue and lethargy throughout the solar day; to annul abnormal states that diminish alertness or consciousness (such every bit in narcolepsy); to decrease ambition and promote weight loss; and to raise concentration (especially for those with attentional disorders such as ADHD). Many stimulants are likewise capable of improving mood and relieving anxiety, and are occasionally used to treat symptoms of depression.

The euphoria produced past some stimulants leads to their recreational utilize, so many stimulants are either illegal or very carefully controlled in the Usa. Some may be legally bachelor only by prescription. Addiction to some central-nervous-organisation stimulants tin can quickly lead to medical, psychiatric, and psychosocial deterioration. Drug tolerance, dependence, sensitization, and withdrawal can occur after repeated apply. Over fourth dimension, stimulants can disrupt the functioning of the brain's dopamine system, dampening users' ability to feel any pleasance at all.

Types of Stimulants

Examples of well-known stimulants include amphetamines, MDMA, NDRIs, cocaine, caffeine, and nicotine.

Amphetamines

Amphetamines (such as ephedrine and methamphetamine) are a group of stimulants that increase the levels of norepinephrine and dopamine in the brain through reuptake inhibition—significant they block these neurotransmitters from being reabsorbed back into the neural networks. Amphetamines are known to cause elevated mood and euphoria, and are often used for their therapeutic furnishings. Physicians occasionally prescribe amphetamines to treat major depression, and numerous studies have demonstrated the effectiveness of drugs such every bit Adderall in controlling symptoms associated with ADHD. Due to their availability and fast-acting effects, amphetamines are prime number candidates for abuse.

MDMA

Methylenedioxymethamphetamine (MDMA), known by its common street names Ecstasy and Molly, had a medical application every bit a treatment for low and a psychotherapy aid until 1985, when information technology became a controlled substance. The stimulant effects of MDMA include appetite loss, euphoria, social disinhibition, insomnia, improved free energy, increased arousal, and increased perspiration.

MDMA too has many concrete side furnishings: since MDMA increases the activity of serotonin, the brain becomes depleted of serotonin, causing a rebound sadness or depression in the days following use. MDMA differs from well-nigh stimulants in that its primary pharmacological consequence is on the neurotransmitter serotonin rather than dopamine, epinephrine, or norepinephrine. MDMA also decreases the release of dopamine. The increment in seratonin is acquired because the MDMA prevents seratonin from entering the reuptake site, causing a continued flow, and eventually excess seratonin.

NDRIs

Norepinephrine and dopamine reuptake inhibitors (NDRIs) (such as the antidepressant Wellbutrin) inhibit the uptake of dopamine and norepinephrine, effectively increasing their amounts in the brain and causing a stimulating consequence. Many of these compounds are constructive ADHD medications and antidepressants. These medicines have an extended release mechanism, and are typically less popular for recreational use.

Cocaine: Cocaine, in pulverization grade, is a commonly abused stimulant that produces a sense of euphoria in the user.

Cocaine

Cocaine is fabricated from the leaves of the coca shrub, which grows in the mountain regions of Due south America. In Europe and Due north America, the most mutual grade of cocaine is a white crystalline pulverization. Nearly cocaine use is recreational and its abuse potential is high, and so its auction and possession are strictly controlled in most jurisdictions.

Caffeine and Nicotine

Caffeine is a drug that is found naturally in coffee, tea, soft drinks, and cocoa. Caffeine stimulates the body, increases heart rate and claret pressure level, and facilitates alertness and concentration. The vast bulk (over fourscore%) of people in the United States consume caffeine on a daily basis. In very low concentrations, nicotine also acts as a stimulant, and information technology is one of the main factors responsible for the dependence-forming properties of tobacco.

Hallucinogens

Hallucinogens affect the levels of serotonin or glutamate in the encephalon and are divided into psychedelics, dissociatives, and deleriants.

Learning Objectives

Compare the effects of different types of hallucinogens on the brain

Central Takeaways

Key Points

• Hallucinogens are drugs that alter sensory input to the brain. They are divided into three categories: psychedelics, dissociatives, and deliriants.
• Psychedelics work by interacting with serotonin receptors in the brain and produce a state of empathetic well-being and visual distortion.
• Dissociatives are a subclass of hallucinogens that piece of work by blocking or altering sensory perception.
• Deliriants are very like to dissociatives; they are considered to be "true hallucinogens" because the visuals they produce are difficult or impossible to distinguish from reality.
• Common hallucinogens include MDMA, PCP, and LSD.

Key Terms

• LD50: In toxicology, the median lethal dose of a toxin, radiations, or pathogen required to impale half the members of a tested population later on a specified examination duration.
• antagonist: A chemical that binds to a receptor but does not produce a physiological response, thereby blocking the action of agonist chemicals.
• glutamate: An of import neurotransmitter that plays a key role in long-term potentiation and is important for learning and retention.
• serotonin: An indoleamine neurotransmitter (5-hydroxytryptamine) that is crucial in maintaining a sense of well-being and security and is involved in depression.

Hallucinogens are drugs that change sensory input to the brain. This creates an altered sense of reality, as well every bit a change in emotions and thought patterns. Hallucinogens can connect the conscious listen to the unconscious, delivering thoughts and feelings that would otherwise remain out of our conscious awareness.

Naturally occuring hallucinogen: Hallucinogenic mushrooms often have a characteristic blue bruising on their stems.

Hallucinogens are divided into three categories: psychedelics, dissociatives, and deliriants.

Psychedelics

Psychedelics are distinguished from the other two subclasses by their lack of addictive qualities, as well as the remarkable experiences one may have under their influence. Most (but not all) psychedelics are not-toxic and have a very high LD50. This means that the user would have to ingest or have very large amounts of the drug, many times that of a recreational dose, in order to impale themselves. The resulting experiences, however, tin can be extremely overwhelming, often driving users to seek emergency help.

Effect of Psychedelics on the Brain

Most psychedelics work past interacting with serotonin receptors in the encephalon. Furnishings include increased breathing and heart rate, dilated pupils, dehydration, increased color perception, a state of compassionate well-existence (feeling equally though one is at peace with everyone and everything), and visual baloney: things may appear to movement, shapes may announced on textures and exhibit a kaleidoscope-like effect, or lighting may dramatically change for no apparent reason.

Dissociatives

Dissociatives are a subclass of hallucinogens that work by blocking or altering sensory perception (including senses that are perceived by the unconscious mind), creating a feeling of disconnection and depersonalization from one's trunk and reality in general. Many dissociatives are strong depressants, and big doses can tiresome downward the center or breathing to the point of causing death. Generally they are not physically addictive, but tin exist habit forming if used repeatedly in a brusk time bridge.

Outcome of Dissociatives on the Brain

Most dissociative drugs simulate a dream-like experience. As with psychedelics, a mixing of the senses tin lead users to believe they tin see sounds or taste textures. Primary dissociatives are NMDA antagonists, which cake glutamate from inbound its receptors and regulating brain function.

Deliriants

Deliriants are very like to dissociatives, and are considered to be true hallucinogens because the visuals they produce are difficult or impossible to distinguish from reality. Nether their influence, users will ofttimes take entire, rational conversations with people who aren't actually there. Some people may meet their ain reflection and believe information technology is another person copying their actions. Users frequently retain awareness of their concrete environment, only are consciously impaired. Almost all deliriants are toxic enough that in that location is a very small divergence, in terms of quantity used, betwixt a recreational dose and a lethal 1. Both Benadryl and Dramamine are deliriants when taken in extremely high quantities.

Issue of Deliriants on the Encephalon

Deliriants piece of work past inhibiting acetylcholine, a neurotransmitter responsible for cognition and stimulation. By contrast, when you drinkable a cup of coffee, your acetylcholine increases, leading to enhanced alertness and focus.

Mutual Hallucinogens

Psychedelics

Psilocybin mushrooms, as well known equally "shrooms," are mushrooms that contain the psychedelic compounds psilocybin and psilocin. They are mainly used as recreational drugs, whose effects include euphoria, altered thinking processes, closed- and open-eye visuals, synesthesia, an altered sense of time, and spiritual experiences.

LSD, also a psychedelic, blocks serotonin from the encephalon, which regulates mood, perception, muscle contraction, and other cognitive functions. LSD blocks serotonin because information technology is, structurally, like to serotonin. For this reason, the encephalon mistakes LSD for serotonin and directs information technology to the synaptic cleft (instead of actual serotonin). LSD causes a number of alterations in perception past affecting both cognitive and visual sensory systems, and it changes the sense of time, body-image, and ego. Retentivity is also greatly affected. A typical "trip" can last anywhere between six and ten hours.

Dissociatives

PCP (or affections dust), a dissociative, prevents the actions normally caused when a neurotransmitter called glutamate is able to attach to its receptor in the encephalon. It also disrupts the actions of other neurotransmitters. This drug is addictive, and its effects are very unpredictable. For example, it may make some people hallucinate and become ambitious, while others may become drowsy and passive.

Dextromethorphan is the active ingredient in virtually over-the-counter and prescription cough medicines. When used in excess of specified maximum dosages, dextromethorphan acts as a dissociative. It can produce effects similar to the dissociative states created by other dissociative anaesthetics such as ketamine and phencyclidine.

Nitrous oxide, usually known as laughing gas, is used in surgery and dentistry for its anaesthetic and analgesic furnishings. It is known equally laughing gas due to the euphoric furnishings of inhaling it, a property that has led to its recreational utilise every bit a dissociative hallucinogen.

Deliriants

While deliriants are often naturally occuring (in plant species), constructed compounds such asdiphenhydramine (Benadryl) and dimenhydrinate (Dramamine) are also deliriants. Uncured tobacco is also a deliriant due to its very high nicotine content, resulting in a febrile hallucinogenic intoxication. Despite the fully legal status of several common deliriant plants, deliriants are largely unpopular as recreational drugs because of their unfavorable furnishings.

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Source: https://courses.lumenlearning.com/boundless-psychology/chapter/how-psychoactive-drugs-impact-the-brain/

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