Transcript Animals in drug research

Unit 3 – Health psychology:
substance misuse
The use of animals in drug research
The specification requires that you are able to:
• Describe and evaluate* the use of animals in
laboratory studies when researching into
drugs
• Evaluate*, including relative strengths and
weaknesses, research methods using animals
(including both practical and ethical strengths
and weaknesses)
Therefore the Learning Objectives for this
session are that you will be able to:
• Describe how, and explain why animals are
used in drug research
• Describe advantages of using animals for
drug research (practical and/or ethical)
• Describe disadvantages of using animals for
drug research (practical and/or ethical)
Answer a past exam paper question on this
topic and identify areas for improvement
Animal research on drugs...
• Biological and medical research - this is concerned
with what keeps us (and animals) alive and healthy
• For example – the brain; in relation to substance
misuse, this involves investigating the effects that
various substances have on the brain
• This is important for our understanding of the mode
of action of substances at the synaptic level, issues
of tolerance, withdrawal and physical dependence
and subsequently, for developing treatments for
substance misuse
For example:
• Rats were used to examine the effects of
chronic stress on ethanol (aka ethyl alcohol!)
intake by Nagaraja & Jeganathan (2003)
• They found that the group of rats who were
subjected to chronic stress (measured by
overcrowding) increased their ethanol intake
and ethanol preference over other liquids
available, in comparison to the control group
( who were subjected to acute stress)
Another example:
• Meisch (2001) used rhesus monkeys to
investigate whether drugs are reinforcing
• The monkeys were given the opportunity to selfadministrate drugs* orally
• *A range of drugs (opioids, stimulants and
ethanol) were used
• Findings showed that drugs such as these are
reinforcing when taken orally; the monkeys
chose to take the drugs as a reward – this links
to the issue of addiction and substance misuse
• So, why use animals for drug research?
• Basically, in order to do research which
couldn’t be conducted with humans for
ethical reasons
• Cost is an issue also – it is cheaper to
research with animals than humans
(they are not as high maintenance!)
Issues to consider when using animals ...
• Ethical issues:
o Causing pain and fear
o Social isolation
o Numbers of animals
o Choice of species
• Practical issues:
o Similarities / differences between animals and
humans
o Controls
o Benefits for animals
Animal research – the 3 Rs …
• The people who work in laboratories with animals often get
bad press; however, they have no interest in mistreating
animals
• For many of them it is their primary responsibility to look
after the animals, and they work with laboratory animals
because they are animal lovers
• Many are also actively involved in developing scientific
methods to reduce the need for animals or replace them
entirely
Animal research – the 3 Rs …
• Good science and good animal welfare go hand in
hand; if an animal is suffering stress or pain it could
affect the results of the research
• Therefore, it makes good scientific sense to house
animals in the best possible conditions and make sure
they get the best possible care from skilled and
experienced carers
• What animals need is not always the same as what
people think they need, so scientists are studying
which environments different animals prefer
Animal research – the 3 Rs …
• Any researcher planning to use animals in their
research must first show why there is no alternative
and what will be done to minimise numbers and
suffering, ie:
• Replace the use of animals with alternative
techniques, or avoid the use of animals altogether
• Reduce the number of animals used to a minimum, to
obtain information from fewer animals or more
information from the same number of animals
• Refine the way experiments are carried out, to make
sure animals suffer as little as possible; this includes
better housing and improvements to procedures
which minimise pain and suffering and/or improve
animal welfare
Evaluation – ethical issues …
In the UK, the use of animals in laboratories is
monitored and regulated by Home Office licence,
so checks on their welfare are more likely than
checks on the welfare of human participants!
If long-term negative effects of a drug manifest, it
is considered that it is better that an animal
suffers these than a human
Where studies cannot use human participants for
ethical reasons, animals can be used because they
are seen as expendable
Evaluation – ethical issues …
It has been argued that current ethical guidelines
do not do enough to protect laboratory animals
from physical and psychological harm
Speciesism - ‘a prejudice or bias in favour of the
interests of members of one's own species and
against those of members of other species’;
involves the judgment that being human is a good
enough reason for human animals to have greater
moral rights than non-human animals
Evaluation - practical issues
Higher levels of control are possible with animals
than humans; animals have been specifically bred for
research purposes and raised in controlled environments, so
the effects of prior experiences can be controlled
Animal research is generally cheaper; amounts of
substances needed are smaller and ensuring the welfare of
animals is less expensive than ensuring the welfare of
humans
Findings from animal research have highlighted the
processes involved in addiction to substances at the synaptic
level; this has then been investigated in humans under less
rigorous conditions
Evaluation - practical issues
• Extrapolation - can data from animal
experiments be unproblematically generalised
to humans?
• Yeah, but ….
• Mammalian brains are similar in structure
across species
• All mammals partake in major categories of
human behaviour: cognitive (memory, attention,
perception), affective (emotional – fear, anger
etc), motivational (aroused and directed
behaviour – feeding, drinking, exploring)
Evaluation - practical issues
• No, but …
• Animals are not necessarily good models for
humans, so results are not necessarily
generalisable, because …
• Different mammalian species have different genetic
and evolutionary histories, so they evolve in
different ways and at different rates
• This links to an ethical issue – if findings cannot be
generalised to humans, then the animals have
suffered for no purpose
Evaluation - practical issues
• Also ...
• Findings from animal research cannot be used to
explain the interaction between experiences,
genetics and drugs which has been found in human
drug use/misuse
• For example, it has been found that environmental
cues can affect how people respond to drugs (how
quickly they respond, intensity of response); it is
extremely difficult to investigate this using animals
(vastly different social environments and cues)