How do street drugs affect the brain?
Lexova kete artikull interesant dhe mendova ta copy+paste ketu per ato qe jane kurjoze... /pf/images/graemlins/smile.gif
How do street drugs affect the brain?
By Judy Foreman, 11/5/2002
''George'' is 17, tall, good-looking, quiet - and a prime example of what kids know and don't know about illegal drugs. The son of a friend of mine, George knows a lot - and I mean, a lot - about drugs.
Asked what he takes, he rattles off pot, alcohol and `shrooms (mushrooms), which he and a friend grow. But he's also done acid (LSD), crack (cocaine), crystal meth (a form of methamphetamine), prescription tranquilizers, and painkillers such as Valium and Percocet, and, oh, yeah, GHB, ecstasy, and mescaline.
He learned to ''cook'' meth using such ingredients as decongestants and brake cleaner at an expensive residential treatment facility. Asked whether he wants to get clean, he says, ''Not right now. My use is just recreational.''
The latest federal government figures, released in September, show that illegal drug use is up among people between 18 and 25. In Massachusetts, cocaine in particular is increasingly popular among middle and high school students, a state study revealed last week.
Despite what George and America's other 16 million illicit drug users seem to know about street drugs, there's undoubtedly a lot they don't know, especially how such drugs affect the brain. Herewith, a quick primer.
One main class of street drugs is the psychostimulants, which include amphetamines (including methamphetamines and MDMA, also known as ecstasy) and cocaine. In low doses, amphetamines generate feelings of euphoria and alertness. But at higher doses, these drugs can trigger paranoia and psychosis.
Amphetamines are both psychologically and physically addicting. They can increase blood pressure and heart rate. Because they also dangerously constrict blood vessels, they ''deprive the heart of blood flow while forcing it to do more work,'' says psychopharmacologist Glen Hanson, acting director of the National Institute on Drug Abuse.
Amphetamines force the brain to pump out 30 to 40 times the normal levels of neurotransmitters, most notably dopamine, serotonin, and norepinephrine, Hanson says. The immediate effect is to activate the brain's ''reward'' circuits.
But over-revving this circuitry can cause violent behavior. Chronic stimulation also depletes brain cells so that they may no longer produce normal levels of neurotransmitters.
By contrast, MDMA, or ecstasy (or simply E), now used by nearly a million people, works somewhat differently. As one might guess from its chemical name (3,4-methylenedioxymethamphetamine), MDMA is an amphetamine.
Until recently, scientists thought that MDMA worked primarily on serotonin, initially increasing levels dramatically, creating such a flood of good feeling that users called it the ''love drug.''
But after a weekend on ecstasy, MDMA users, George among them, report that depression (or ''E-pression'') strikes as serotonin levels plummet. MDMA can also induce muscle tension and an unpleasant, involuntary clenching of teeth, notes Dr. Patrick E. McKinney, an emergency room physician and medical director of the New Mexico Poison and Drug Information Center in Albuquerque. In addition, MDMA can trigger such high body temperatures - 107 to 108 degrees Fahrenheit - that seizures, multiorgan failure, and even death can result.
And there are longer-term effects as well. In one set of studies, Dr. Una D. McCann, associate professor of psychiatry and behavior sciences at Johns Hopkins School of Medicine, and her husband, Dr. George A. Ricuarte, associate professor of neurology at Johns Hopkins, found MDMA is toxic to neurons that make serotonin in monkeys, baboons, and humans.
McCann and Ricuarte have documented neural damage in humans using both PET scans, a brain imaging technique, and tests for a breakdown product of serotonin. The implications are serious - without sufficient serotonin, sleep, mood, memory, and other crucial brain functions may be disrupted.
Recently, in a paper in Science, Ricuarte's group showed that in animals, ecstasy lowers levels of dopamine as well as serotonin, raising the risk of Parkinson's disease. So far, however, there appear to be no increased rates of Parkinson's disease among human ecstasy users. On the plus side, the benefits of ecstasy are beginning to be taken seriously as well. Last fall, the US Food and Drug Administration approved a study of ecstasy as an aid to psychotherapy.
Cocaine damages the brain in a different way, notes Dr. Marc Kaufman, a research pharmacologist at McLean Hospital in Belmont. Cocaine revs up the brain's ''reward'' circuitry, but unlike MDMA, it does its damage not by directly affecting neurons that make neurotransmitters, but by reducing blood flow to parts of the brain. By causing blood vessels to narrow, it raises the risk of stroke and heart attack. Using MRI scans of the brain, Kaufman and others have also shown that women are somewhat protected against cocaine damage because estrogen helps keep blood vessels open.
Other popular street drugs are depressants, among them, GHB and Rohypnol, the ''date rape'' drugs.
GHB, technically called gamma hydroxybutyrate, is also known as ''liquid ecstasy'' or ''Georgia HomeBoy.'' It can be easily slipped into a person's drink. Like alcohol and the tranquilizer Valium, GHB acts through GABA receptors, the brain's intrinsic tranquilizer system: when GABA receptors are activated, neural activity slows down.
So far, GHB has not been shown to damage neurons. But it can relax users to the point of rendering them incapable of resisting unwanted sex. It can also lead to coma and even to death; alcohol can enhance this effect.
Rohypnol has similar effects. Dubbed ''Roofies,'' Rohypnol is a benzodiazepine, a strong tranquilizer. Like GHB, it works through GABA receptors and receptors for benzodiazepine as well. Rohypnol, which is legally available overseas as a sedative, can also trigger amnesia, making it treacherous in the hands of anyone seeking to coerce someone into sex and render a victim unable to recall events.
Ketamine, a powerful anesthesia drug often used by veterinarians, is another popular downer. Known as ''K'' and ''Special K,'' it acts by blocking yet another type of receptor in the brain, producing general anesthesia.
The bottom line with all drugs of abuse, says Hanson, is that recreational use can turn into a ''game of Russian Roulette.'' Street drugs ''don't kill everyone who takes them.'' And obviously, not everyone becomes addicted. But he adds, ''The benefits just do not warrant the kind of risk you are exposing yourself to.''
George, among others, is not convinced. ''I think it all comes down to the person. We are all different, with such different brain chemistry,'' he says.
Lexova kete artikull interesant dhe mendova ta copy+paste ketu per ato qe jane kurjoze... /pf/images/graemlins/smile.gif
How do street drugs affect the brain?
By Judy Foreman, 11/5/2002
''George'' is 17, tall, good-looking, quiet - and a prime example of what kids know and don't know about illegal drugs. The son of a friend of mine, George knows a lot - and I mean, a lot - about drugs.
Asked what he takes, he rattles off pot, alcohol and `shrooms (mushrooms), which he and a friend grow. But he's also done acid (LSD), crack (cocaine), crystal meth (a form of methamphetamine), prescription tranquilizers, and painkillers such as Valium and Percocet, and, oh, yeah, GHB, ecstasy, and mescaline.
He learned to ''cook'' meth using such ingredients as decongestants and brake cleaner at an expensive residential treatment facility. Asked whether he wants to get clean, he says, ''Not right now. My use is just recreational.''
The latest federal government figures, released in September, show that illegal drug use is up among people between 18 and 25. In Massachusetts, cocaine in particular is increasingly popular among middle and high school students, a state study revealed last week.
Despite what George and America's other 16 million illicit drug users seem to know about street drugs, there's undoubtedly a lot they don't know, especially how such drugs affect the brain. Herewith, a quick primer.
One main class of street drugs is the psychostimulants, which include amphetamines (including methamphetamines and MDMA, also known as ecstasy) and cocaine. In low doses, amphetamines generate feelings of euphoria and alertness. But at higher doses, these drugs can trigger paranoia and psychosis.
Amphetamines are both psychologically and physically addicting. They can increase blood pressure and heart rate. Because they also dangerously constrict blood vessels, they ''deprive the heart of blood flow while forcing it to do more work,'' says psychopharmacologist Glen Hanson, acting director of the National Institute on Drug Abuse.
Amphetamines force the brain to pump out 30 to 40 times the normal levels of neurotransmitters, most notably dopamine, serotonin, and norepinephrine, Hanson says. The immediate effect is to activate the brain's ''reward'' circuits.
But over-revving this circuitry can cause violent behavior. Chronic stimulation also depletes brain cells so that they may no longer produce normal levels of neurotransmitters.
By contrast, MDMA, or ecstasy (or simply E), now used by nearly a million people, works somewhat differently. As one might guess from its chemical name (3,4-methylenedioxymethamphetamine), MDMA is an amphetamine.
Until recently, scientists thought that MDMA worked primarily on serotonin, initially increasing levels dramatically, creating such a flood of good feeling that users called it the ''love drug.''
But after a weekend on ecstasy, MDMA users, George among them, report that depression (or ''E-pression'') strikes as serotonin levels plummet. MDMA can also induce muscle tension and an unpleasant, involuntary clenching of teeth, notes Dr. Patrick E. McKinney, an emergency room physician and medical director of the New Mexico Poison and Drug Information Center in Albuquerque. In addition, MDMA can trigger such high body temperatures - 107 to 108 degrees Fahrenheit - that seizures, multiorgan failure, and even death can result.
And there are longer-term effects as well. In one set of studies, Dr. Una D. McCann, associate professor of psychiatry and behavior sciences at Johns Hopkins School of Medicine, and her husband, Dr. George A. Ricuarte, associate professor of neurology at Johns Hopkins, found MDMA is toxic to neurons that make serotonin in monkeys, baboons, and humans.
McCann and Ricuarte have documented neural damage in humans using both PET scans, a brain imaging technique, and tests for a breakdown product of serotonin. The implications are serious - without sufficient serotonin, sleep, mood, memory, and other crucial brain functions may be disrupted.
Recently, in a paper in Science, Ricuarte's group showed that in animals, ecstasy lowers levels of dopamine as well as serotonin, raising the risk of Parkinson's disease. So far, however, there appear to be no increased rates of Parkinson's disease among human ecstasy users. On the plus side, the benefits of ecstasy are beginning to be taken seriously as well. Last fall, the US Food and Drug Administration approved a study of ecstasy as an aid to psychotherapy.
Cocaine damages the brain in a different way, notes Dr. Marc Kaufman, a research pharmacologist at McLean Hospital in Belmont. Cocaine revs up the brain's ''reward'' circuitry, but unlike MDMA, it does its damage not by directly affecting neurons that make neurotransmitters, but by reducing blood flow to parts of the brain. By causing blood vessels to narrow, it raises the risk of stroke and heart attack. Using MRI scans of the brain, Kaufman and others have also shown that women are somewhat protected against cocaine damage because estrogen helps keep blood vessels open.
Other popular street drugs are depressants, among them, GHB and Rohypnol, the ''date rape'' drugs.
GHB, technically called gamma hydroxybutyrate, is also known as ''liquid ecstasy'' or ''Georgia HomeBoy.'' It can be easily slipped into a person's drink. Like alcohol and the tranquilizer Valium, GHB acts through GABA receptors, the brain's intrinsic tranquilizer system: when GABA receptors are activated, neural activity slows down.
So far, GHB has not been shown to damage neurons. But it can relax users to the point of rendering them incapable of resisting unwanted sex. It can also lead to coma and even to death; alcohol can enhance this effect.
Rohypnol has similar effects. Dubbed ''Roofies,'' Rohypnol is a benzodiazepine, a strong tranquilizer. Like GHB, it works through GABA receptors and receptors for benzodiazepine as well. Rohypnol, which is legally available overseas as a sedative, can also trigger amnesia, making it treacherous in the hands of anyone seeking to coerce someone into sex and render a victim unable to recall events.
Ketamine, a powerful anesthesia drug often used by veterinarians, is another popular downer. Known as ''K'' and ''Special K,'' it acts by blocking yet another type of receptor in the brain, producing general anesthesia.
The bottom line with all drugs of abuse, says Hanson, is that recreational use can turn into a ''game of Russian Roulette.'' Street drugs ''don't kill everyone who takes them.'' And obviously, not everyone becomes addicted. But he adds, ''The benefits just do not warrant the kind of risk you are exposing yourself to.''
George, among others, is not convinced. ''I think it all comes down to the person. We are all different, with such different brain chemistry,'' he says.