• 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