Depressants – Alcohol, benzodiazepine, barbiturates, ketamine
Depressants decrease central nervous system (CNS) arousal and excitability levels, giving off a feeling of sedation. Depressants bind to GABA receptors. GABA is the main inhibitory neurotransmitter in the brain. Depressants also block AMPA receptors, which are responsible for excitatory responses. Through these mechanisms, depressants both increase inhibitory effects and suppress excitatory effects, which is why their effects are so strong. Depressants also cause impaired judgment, coordination loss, and amnesia. Depressants are often prescribed as painkillers, such as Valium, or as anti-anxiety drugs, like Xanax. Depressants are also used to treat seizures and insomnia and are used as anesthetics.
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Often abuse begins with a legitimate prescription or social use, but escalates because of the addictive quality of the drugs. When taking depressants, users tend to feel sedated and sleepy and sometimes experience dissociative feelings, like they are outside of their own body. Withdrawal lasts several days and the withdrawal itself can often lead to serious medical problems. Depressing the CNS reduces the experience of anxiety, which makes depressants a common substance of choice for those seeking an “escape” from their own stress. Thus, the drugs are both chemically and psychologically addictive.
Stimulants - Cocaine, amphetamine, methamphetamine, ephedrine, MDMA/ecstasy (also a hallucinogen), PCP (also a hallucinogen), caffeine, nicotine, etc.
Stimulants increase CNS activity. Stimulants prevent certain chemicals from being reabsorbed, so the synaptic space becomes overloaded with neurotransmitters, particularly dopamine, norepinephrin, and serotonin. Stimulants are often used to increase alertness and productivity (caffeine, Ritalin) or induce a euphoric state (cocaine, MDMA).
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Because stimulants increase neural activity and cause physiological arousal, they can also cause paranoia and anxiety. Withdrawal from stimulants typically lasts several days. They are highly addictive because the body quickly builds tolerance to stimulants, so the user needs to take more to get the same high or avoid withdrawal. The reinforcing effects are strong, but often leave damage to the stress-response system and emotional regulation, even if use is short-lived.
Hallucinogens - LSD, MDMA/ecstacy, PCP, ketamine, mescaline, mushrooms
Effects of these drugs can range from visual or, more rarely, auditory hallucinations, to euphoric and dissociative sensations. People often report experiencing some altered state of consciousness that can range from euphoric to terrifying. Research shows that hallucinogens primarily affect serotonin neurotransmitters, but not much more is known about how hallucinations are produced. Hallucinogens do not have any current medical uses, though ketamine was formerly used as an anesthetic. These drugs are used recreationally, generally in group settings or as part of some cultural ritual. Hallucinogens are generally synthetically made, though some types occur naturally (mushrooms). While certain hallucinogens do not have reinforcing effects (LSD, MDMA), others do seem to have addictive properties (PCP, ketamine) because of a stimulant or depressant being mixed in. Most hallucinogens have relatively long effect (4-12 hours), but also often require a much longer recovery period than other classes of drugs, sometimes up to a full day. Use may lead to undesired hallucinations long after the drug use.
Narcotics/Opioids - Opium, heroin, methadone, etc.
Opiods and Morphine derivatives are highly addictive. These drugs work on the dopaminergic system, giving a strong pleasure response. Narcotics are one of the most addictive classes of drugs because people quickly build tolerance to the substance and have strong withdrawal effects. Withdrawal lasts several days or longer. Like other drugs of abuse, narcotic use can lead to long-term damage to stress-response and emotion-regulation systems. These drugs typically produce sedative effects and euphoric states. Some opiods are used as painkillers, like Oxycotin.
Cannabinoids (hallucinogen according to the CSA) - Marijuana, hashish
Cannabinoids include marijuana, hashish, and other cannabis derivatives. Marijuana binds to cannabinoid receptors in the brain. THC, the active component of marijuana creates a “high” that is generally sedated, but not immobilizing as many depressants and opiods. Immediate effects of
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How do Drugs affect the synapse?
Different drugs work differently in the synapse. No one drug does exactly the same thing in the same way. To find out how each drug affects humans in the synapse, go to Mouse Party. Push play, and then find out how each drug affects the synapse by dragging the mouse to the chair. You need to know how the following drugs work in the synapse:
- Cocaine
- Alcohol
- LSD
- Heroin
- Marijuana
This website from McGill University has the same information, but shown in a slightly different way. Note that LSD is not mentioned on this website.
What should we do about dangerous drugs? How should we treat addiction?
Traditionally, taking illicit drugs (e.g., cocaine) and improperly taking prescription drugs has been treated as a criminal act. Societies treat addictive tendencies as behaviors that can be curbed with harsh penalties and law enforcement. But new perspectives suggest that this may be the wrong approach. Watch this TED talk by Johann Hari:
Watch: Everything you think you know about addiction is wrong