K0736174
Malgorzata Basta
Describe the stimulant and sedative effects of drugs, both at the neural transmission level and
the behavioural level ,giving examples of each type of effect .
According to Oxford Dictionary of Psychology drug is “any chemical substance that
can affect the structure or function of a livinig body ,often used as a medicine ,or in making a
medicine or taken for its pleasure or satisfying effect”1. Moreover: ”broadly speaking, is any
chemical substance that, when absorbed into the body of a living organism, alters normal
bodily function.”2. Drugs are enemy that will destroy us ,unless we destroy them and they are
having destructive physiological and psychological effect on our organism. Neurons relase
many different kinds of transmitter substance,and various drugs can affect the production or
release of one or more of those chemicals .
I would like to concentrate on stimulant and sedactive effect and give an example of each
effect.Some drugs stimulate certain terminal buttons to relase their transmitter substance
countinously however other prevent certain terminal buttons from releasing their transmitter
substance.
Transmitter substances produce their effects by stimulating postsynaptic receptor
molecules ,which excite or inhibit postsynapic neurons by opening ion channels and
permitting ions to enter or leave the neurons.”Some drugs duplicate the effects of particular
transmitter substance on a receptor molecules”3.If we use the lock and key analogy to describe
the effects of a transmitter substance on a receptor molecule than a drug that stimulates
receptor molecules works like a master key ,turning the receptor molecules on even when the
transmitter substance is not present. Good ilustration is nicotine which stimulates
acetylcholine receptors located on neurons in certain regions of the brain. In low doses ,this
stimulation has a plesurable excitatory effect.In high doses it can cause convulsions and
death.Some drugs block receptor molecules ,making them inaccessible to the transmitter
substance and thus inhibiting synaptic transmission. The most popular stimulant drugs are
amphetamine and cocaine –they inhibit the reuptake of dopamine and sterengthen the
effectiveness of synapses that use this transmitter substances.
1
Oxford Dictionary of Psychology Andrew M.Colman ,Oxford University Press ,p.228
World Health Organisation. (1969). WHO Expert Committee on Drug Dependence. Sixteenth report.
(Technical report series. No. 407).Geneva:World Health Organisation.
3
Psychology G.Neil Martin, Neil R.Carlson,William Buskist ,Person ,p.158
2
-2-
Sedative effect coused some drugs –anti-anxiety or anxiolytic drugs and it’s connected
with depress behaviour , relaxation or sometimes loss of consciousness. In most cases ,the
depression is caused by stimulation of a class of receptor molecules and it’s activated by
neuromodulators produced by the brain .Barbiturates depress the brain’s activity by
stimulsting a particular category of neuromodulator receptors. “In small doses barbiturates
have a calming effect .In higher doses they produce difficulty in wolking and talking
unconsciousnrss coma and deth.”4.Is used by people who want to achive the relaxind and
calming effect and their are sometimes prescribed as a medication for sleep.
Anti-anxiety drugs are called benzodiazepines ,which include Valium. “Drug stimulate some
sort of neuromodulator receptors located on neurons in many parts of the brain including the
amygdala.”5This drugs are effective in reducing anxiety and ocasionally used to treat people
who are affected by periodic attacks.
This behavioural effect suggest that they are involved in the regulation of mood and as a
control of sleeping. Similar depresant drug is ethyl alcohol which has very similar effect to
those of barbiturates .Larger doses of alcohol reduce anxiety ,disrupt motor coordination and
then cause unconsciousness coma and finally death.
In conclusion it’s very important to mention that no metter how and which drug we use there
will be always fatal effect to our organism . Drugs can affect consciousness in several
different ways and there is only one step to be drug addict and to destroy our body and even
die.
REFERENCES:
1/ Oxford Dictionary of Psychology Andrew M.Colman ,Oxford University Press
2/ WHO Expert Committee on Drug Dependence. Sixteenth report. (Technical report series. No.
407).Geneva:World Health Organisation.
3/ Psychology G.Neil Martin, Neil R.Carlson,William Buskist ,Person
4/ Drugs and Drug Use in Society, Ross Coomber, Greenwich Readers, Greenwich University Press
5/ Drugs. Cultures ,Control & Everyday Life ,Nigel South ,Sage Publications
4
5
op. cit.p.159
Drugs and Drug Use in Society, Ross Coomber, Greenwich Readers, Greenwich University Press p.18