types of psychoactive drugs how they work. 4 ways that drugs work: 1.some drugs, like heroin and...
TRANSCRIPT
• Types of Psychoactive Drugs• How they work
PSYCHOACTIVE DRUGS
How nerve impulses work
Almost all drugs that change the way the brain works do
so by affecting chemical neurotransmission
4 WAYS THAT DRUGS WORK:
1. Some drugs, like heroin and LSD, mimic the effects of a natural neurotransmitter
2. Others, like PCP, block receptors and thereby prevent neuronal messages from getting through
3. Some, like cocaine, interfere with the molecules that are responsible for transporting neurotransmitters back into the neurons that released them
4. Finally, some drugs, such as Methamphetamine, act by causing neurotransmitters to be released in greater amounts than normal
A psychoactive drug is a substance that alters perceptions and mood
Dependence can be physical:Physiological needMarked by unpleasant withdrawal symptoms
Or dependence can be psychological:Eg to relieve negative emotions
Tolerance is needing more of the drug to get the same effect
Depressants Reduce neural activity Slow body functions Alcohol, barbiturates, opiates
Stimulants Excite neural activity Speed up body functions Caffeine, nicotine,
amphetamines, cocaine
Hallucinogens Psychedelic drugs that distort
perceptions and cause sensory images (hallucinations) in the absence of sensory input
LSD, marijuana http://
www.ceida.net.au/drugs.asp
Types of
Psychoactive Drugs
* Affect CNS by increasing heart rate, blood pressure, & muscular tension* Increase attentiveness, less need for sleep and food, can reduce anxiety* Caffeine can improve mood by mimicking brain chemical, adenosine
Eg. amphetamines, ecstasy, nicotine, caffeine and cocaineCOCAINE:Snorted, smoked, or injectedIncreases well being, confidence, alertness, decreases appetiteAffects the neurotransmitter “dopamine”: normally, excess dopamine in a
synapse is reabsorbed by the releasing axonCocaine blocks reabsorption, flooding brain with dopamine pleasurable
sensationsAfterwards, no dopamine is left over, and this produces the “crash” –
feeling down, depressed once drug is worn offVery addictive
STIMULANTS
DEPRESSANTS (“downers”) Reduce anxiety, slow down mental function, neurons fire more slowly Inhibit brain’s normal functioning Speech can become slurred, muscle control is reduced Eg. alcohol, barbiturates, benzodiazepenes Benzodiazepines enhance the effect of the neurotransmitter gamma-
aminobutyric acid, which results in sedative, hypnotic (sleep-inducing), anxiolytic (anti-anxiety), anticonvulsant, muscle relaxant and amnesic action.[2] These properties make benzodiazepines useful in treating anxiety, insomnia, agitation, seizures, muscle spasms, alcohol withdrawal and as a premedication for medical or dental procedures.
NARCOTICS
Increase relaxation, relieve pain & anxiety
Also have a euphoric effectEg. morphine & heroin, oxycodone, codeine
HALLUCINOGENSPsychedelic drugs produce a loss of contact with reality: •Produce changes in perceptions, like: •HALLUCINATIONS -- perceptions that have no direct external
cause – seeing, hearing, feeling, etc. things that don’t exist. Hallucinations can be caused by hypnosis, meds, withdrawal from drugs, psychological breakdowns, prolonged sleep deprivation
•Eg. Marijuana – scientific name - Cannabis sativa (Indian hemp)active ingredient THC (tetrahydrocannabinol) It is usually smoked by various methods, but is also eaten in many various
forms – there are also lotions for medicinal uses Can produce euphoria, well being, but can also produce paranoia and sadness Makes sensory experiences more intense Magnifies both + and – feelings Impairs memory