The biological model views
mental illness much as it
views physical illness and
hence refer to psychological
problems as ‘illness.’
1. Assumptions
Psychological
illnesses have a
physical cause
(genetic, chemical,
anatomical etc.)
Treatment of
psychological illness
will require a physical
intervention (surgery
or drug treatment for
example).
2. Explanations
Genetic
Bilogical illness is inherited from
parents. This could be shown if
there is a tendency for an illness to
run in the family or if a particular
gene can be identified as being
responsible for the disorder.
Usual methods of study
include family, twin or
adoption studies that look for
links between individuals with
a similar genetic make up
For example if one twin has
schizophrenia there is on average
about a 42% chance that their
identical brother or sister will also
develop the disorder. This obviously
suggests that schizophrenia is not
100% genetic, but it also suggests
that there is a genetic element to it.
Biochemistry
The brain relies on various
chemicals to help it
communicate, these are called
neurotransmitters. Examples
include adrenalin, serotonin and
dopamine. Perhaps an imbalance
in these chemicals can lead to
psychological disorders.
We know that LSD can cause
similar symptoms to being
schizophrenic and we know that
LSD is chemically similar to
the brain chemical dopamine.
There is a clear link between
brain chemistry and genes.
It appears that the schizophrenic brain is
overly sensitive to this neurotransmitter so
as a result messages get passed on that
would be blocked out in a ‘normal’ brain.
Drugs such as chlorpromazine, used to treat
some of the symptoms of schizophrenia
make the brain less sensitive to dopamine.
Neuroanatomy
Considers the possibility
that abnormal behaviour may
be caused by a problem with
the structure of the brain
We know that brain damage can
cause catastrophic alterations to
performance and behaviour, for
example Clive Wearing
There is less evidence to support
this aspect of the theory. Possible
exceptions are a link between
enlarged ventricles (fluid filled
chambers in the brain) and some of
the symptoms of schizophrenia, and
a possible link between the
hypothalamus and eating disorders
Infection
Infections can clearly
cause physical illness
such as colds, flu,
meningitis etc
Some evidence has
suggested that
influenza during the
middle section of
pregnancy, can lead to
an increased incidence
of schizophrenia when
the child reaches
maturity.
Evaluation of the biological model
The model has lead to a number of widely used
and effective treatments for various disorders.
Drugs have the added
bonus of being quick and
easy to take compared to
psychological treatments
that can take months and
be very costly.
There is the
problem of cause
and effect.
No psychological disorder has a 100% concordance
rate when MZ twins are compared. There are many
cases of one twin having a psychological disorder and
their identical twin showing no symptoms.
There is the danger that if we
concentrate on physical definitions and
physical treatments that we ignore the
root causes of psychological illness