Download PSYCHOACTIVE DRUGS

•
Types of Psychoactive Drugs
• How they work
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 need
 Marked 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
STIMULANTS
* 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 cocaine
COCAINE:
Snorted, smoked, or injected
Increases well being, confidence, alertness, decreases appetite
Affects the neurotransmitter “dopamine”: normally, excess dopamine in a
synapse is reabsorbed by the releasing axon
Cocaine blocks reabsorption, flooding brain with dopamine  pleasurable
sensations
Afterwards, no dopamine is left over, and this produces the “crash” –
feeling down, depressed once drug is worn off
Very addictive
DEPRESSANTS (“downers”)




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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 gammaaminobutyric 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.
Increase relaxation, relieve
pain & anxiety
Also have a euphoric effect
Eg. morphine &
heroin, oxycodone,
codeine
HALLUCINOGENS
Psychedelic 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